A recent impaired-driving case in Minnesota revealed that an expired calibrator was used in blood alcohol testing at the Midwest Regional Forensic Laboratory.

The issue was not identified through routine oversight or public disclosure. It surfaced only after an independent expert (me) requested additional records during the case review.

That discovery led Daniel Koewler and me to publish a new commentary in MinnPost showing why Minnesota needs independent oversight of its forensic laboratories.

The pattern behind the problem

The expired calibrator is not just a one-off issue. It fits into a broader pattern.

In 2025, a Minnesota veteran found himself fighting a DWI case over a urine alcohol result that had been rounded upward by laboratory software.

His measured value was 0.0799, below the legal threshold. But when the laboratory converted the result into statutory units, the software rounded the value up to 0.08.

In 2010, the Tri-County Regional Forensic Laboratory reported urine alcohol concentrations incorrectly because results were not converted into the statutory units required by Minnesota law. This caused alcohol concentrations to be reported higher than they should have been.

In 2011, the state also experienced the Intoxilyzer 5000 source-code controversy, in which a known software patch was not installed for years despite the defect having been identified. This error led to certain valid breath samples being rejected, exposing drivers to harsher refusal penalties.

Minnesota then spent roughly $1.7 million on the DataMaster DMT to replace the Intoxilyzer 5000. The BCA highlighted that the DMT had two methods of analysis: fuel cell and infrared technologies.

Yet one of those analytical components, the fuel cell, was turned off within months of deployment despite being touted as an important quality assurance safeguard.

In 2012, serious problems were uncovered at the St. Paul Police crime laboratory after a court challenge revealed that drug analysts were operating without written standard operating procedures or properly validated testing methods.

Independent reviewers later found major deficiencies in documentation, quality assurance practices, and analytical procedures. Drug testing at the lab was eventually suspended while the problems were investigated.

In 2025, a judge excluded DNA produced by the BCA in Minnesota v. Porter. The evidence generated was found not to be scientifically reliable.

And just last fall, we discovered problems involving dry-gas reference materials used to check breath-testing instruments. This discovery forced prosecutors to dismiss or reevaluate dozens of cases across the state.

Each of these issues may seem technical on the surface. But in forensic science, technical details are the foundation of reliability.

Why these issues matter

When those details are wrong, the consequences affect real cases, real people, and real outcomes in court.

What ties these events together is not just the errors themselves. It is how they are discovered.

Again and again, these problems come to light only after case-by-case scrutiny by defense attorneys and independent experts.

They are not identified through a system designed to catch and disclose them early.

We need forensic oversight

At least 18 states now have forensic science oversight boards or commissions that provide independent review of forensic laboratories and investigate scientific failures.

In 2025, those efforts became more coordinated through the creation of the National Association of Forensic Science Boards.

Minnesota does not currently have anything comparable.

What oversight is really about

The purpose of an oversight is to ensure public labs are doing good science and to investigate errors in the system.

Most forensic scientists are doing careful and professional work under difficult conditions. The issue is the system.

Oversight is about creating a structure that identifies errors early, reviews them independently, and discloses them transparently.

That is how scientific disciplines maintain credibility.

Where Minnesota stands

Right now, Minnesota relies heavily on litigation to surface problems that should be visible through routine quality assurance and public reporting.

That is not an efficient or reliable way to safeguard scientific integrity.

If forensic science is going to carry the weight it does in criminal court, it needs to operate with the same level of openness and accountability expected in other areas of science.

Read the full article here: https://www.minnpost.com/community-voices/2026/03/minnesota-needs-independent-oversight-of-forensic-labs/

I’m excited to share a new paper of mine that was just published in Forensic Science International: Synergy: Unit inconsistency in forensic blood and breath alcohol reporting.

This paper addresses a simple but important issue that has real implications in forensic toxicology.

In many U.S. jurisdictions, such as South Dakota, Massachusetts, and New York, statutes define blood alcohol concentration (BAC) as percent by weight (a mass/mass unit). Modern laboratories, however, measure and report BAC in grams per deciliter (g/dL), a mass/volume unit.

These units are often treated as interchangeable.

They are not.

Because whole blood has a density of approximately 1.055–1.06 g/mL, a value reported in g/dL will be numerically higher than the equivalent percent by weight value.

What does that mean in practice?

A reported BAC of:
0.080 g/dL

when converted to percent by weight becomes:

0.080 g/100 mL ÷ 1.06 g/mL × 100 ≈ 0.075% by weight

That’s about a 6% difference.

In jurisdictions where the statute defines BAC as percent by weight, but laboratories report values in g/dL without reconciling units, this results in systematic overreporting of BAC by approximately 6%.

This extends to breath alcohol as well

Some jurisdictions, such as New York and Massachusetts, do not report breath results directly in g/210 L, but instead express breath alcohol as an equivalent %BAC by weight.

In these cases, the conversion from breath to blood is performed, but the final value is still treated as percent by weight without reconciling the underlying mass/volume units.

Breath alcohol is typically measured as:
0.08 g/210 L (mass/volume)

Assuming the standard 2100:1 blood-to-breath ratio,

0.08g/210 L (breath) corresponds to 0.08g/100 mL (blood)

But that is still a mass/volume value.

Converting to percent by weight:

0.08 g/100 mL ÷ 1.06 g/mL × 100 ≈ 0.075% by weight

The same ~6% difference carries through.

Bottom line

This is not a problem with instrumentation.
It is not a calibration issue.
It is a unit reconciliation issue.

My paper walks through:

• how mass/mass and mass/volume differ in whole blood

• and how this discrepancy carries through both blood and breath alcohol reporting

My goal was to clarify how unit definitions affect interpretation, particularly when comparing laboratory results to statutory BAC thresholds expressed as percentages by weight.

If you work in forensic toxicology, this is a reminder that how we define the measurand can determine how we interpret results.

Excited to share that my latest paper, co-authored with Bethany Pridgen, is now published in Forensic Science International: Synergy: “The limits of accreditation: Monopoly, insularity, and the need for openness in forensic science.”

The central argument: accreditation does not mean what courts think it means.

One organization. 94% of the market.

ANAB accredits roughly 94 percent of all forensic providers in the United States. Combined with A2LA, two private organizations control more than 99 percent of forensic accreditation.

Neither carries the transparency obligations or enforcement mandates of an actual regulatory agency. Yet courts routinely hear that accreditation means a lab operates under the most rigorous standards.

A closed loop

In most non-forensic ISO/IEC 17025 programs, assessors come from diverse technical backgrounds across multiple industries. That outside perspective matters.

Forensic accreditation works differently. ANAB’s program relies on volunteers drawn directly from other crime labs.

They attend the same conferences, belong to the same professional organizations, and operate within the same law enforcement structures as the labs they assess. When your assessor works at a lab, you may assess the next cycle; the incentive to flag problems is structurally suppressed.

Three labs. Three failures. All accredited.

Randox manipulated calibration data for years before a defense expert caught it reviewing raw data in a single case.

Maryland used single-point calibration for blood alcohol testing for a decade, passing two accreditation cycles before anyone cited it.

The UIC lab couldn’t adequately separate delta-8-THC from delta-9-THC internally in 2021 and kept the method in use until 2024.

Accreditation confirmed procedures were being followed in every case. It missed the science.

The bottom line

Accreditation should be the beginning of scrutiny. Not the end of it.

The paper is open access in Forensic Science International: Synergy: https://www.sciencedirect.com/science/article/pii/S2589871X26000148

I was pleased to learn that two of my recent articles are currently featured among the most downloaded papers on the Forensic Science International: Synergy website.

Both articles address issues that I believe are central to the future of forensic science: scientific independence and transparency in forensic testing.

The first article, “Truth, Power, and the Crisis of Forensic Independence,” examines the tension that exists when forensic laboratories operate within law enforcement hierarchies.

When scientists challenge institutional narratives or expose systemic problems, the response is not always scientific debate. Sometimes it is professional retaliation or marginalization. The article argues that true scientific integrity requires institutional independence, transparency, and protection for those who raise legitimate concerns.

The second article, coauthored with Chuck Ramsay, “Errors in Toxicology Testing and the Need for Full Discovery,” reviews toxicology failures across multiple jurisdictions over several decades.

Errors include calibration issues, reporting mistakes, laboratory misconduct, and failures in disclosure. The paper argues that broader discovery and transparency are essential safeguards for both science and justice.

I appreciate the attention these topics are receiving and look forward to continuing to write about issues at the intersection of science, law, and forensic practice.

Forensic toxicology is often viewed as one of the most objective disciplines in forensic science. After all, the results come from analytical instruments like GC-MS or LC-MS. But as Dr. Hilary Hamnett explains in this episode of the podcast, the human decisions surrounding those instruments can still introduce bias.

Dr. Hamnett, an Associate Professor of Forensic Science at the University of Lincoln, spent years working in toxicology laboratories in both the UK and New Zealand before turning her attention to research on cognitive bias in forensic science.

Dr. Hamnett identifies several stages where bias can influence decisions:

• choosing which tests to run

• deciding whether a drug is present

• determining the concentration

• interpreting the results

Interestingly, Dr. Hamnett considers the earliest stage to be the most important. If the wrong tests are selected at the beginning, the rest of the case may be affected.

One example discussed during the episode involved a laboratory that knew a deceased individual had a history of heroin use. Based on that information, the lab immediately performed confirmatory testing for opiates using a limited blood sample. The result was negative. Only later did investigators learn that the individual had transitioned to methadone treatment, which had not been tested for. Because the entire sample had been used, no further testing was possible.

Cases like this highlight how contextual information can shape analytical decisions.

So what can labs do to reduce bias?

Dr. Hamnett suggests several steps, including standardized testing schemes for common case types, greater transparency in reporting, and clearly documenting analytical decisions. These measures help ensure that scientific decisions are driven by procedure rather than assumptions about the case.

Awareness of cognitive bias is growing in forensic science, and Dr. Hamnett believes the field is slowly changing. More laboratories are beginning to adopt bias-minimizing policies, and new guidance is being developed to help labs address human factors in their workflows.

The results may come from instruments, but the decisions around that science are still made by people.

Clips

Instruments aren’t purely objective

Decisions must be written down

Context can mislead in forensic toxicology

Reports must show uncertainty

Learn More

Papers discussed in the episode:

The effect of contextual information on decision-making in forensic toxicology
https://www.sciencedirect.com/science/article/pii/S2589871X20300449

The use of contextual information in forensic toxicology: An international survey
https://www.sciencedirect.com/science/article/pii/S1355030618301230

You can also hear Dr. Hamnett discuss this topic on The Tox Pod:
https://thetoxpod.buzzsprout.com/227318/episodes/8253367-cognitive-bias-with-hilary-hamnett

Automated Transcript (not checked for errors)

Aaron Olson: Welcome to the show. Today we’re joined by Dr. Hillary Hamnet, an associate professor in forensic science at the University of Lincoln and leading expert in forensic toxicology. She has a distinguished career spanning the Royal Society of Chemistry to senior scient scientist
Hilary Hamnett: Thank
Aaron Olson: roles in New Zealand and the UK. Dr. Dr. Hamnet also serves as a specialized defense consultant navigating the complex intersection of drugs, toxicology, and cognitive bias. Dr. Hamnet, thanks so much for joining me on the show.
Hilary Hamnett: you. It’s good to be here.
Aaron Olson: So, tell me a little bit about your background. You your work for focuses on cognitive bias and forensic toxicology, at least some of your recent papers. Tell me a little bit how you got into this area of science.
Hilary Hamnett: Yeah. So I guess much like yourself, I um have a background as a practicing forensic toxicologist. Um and I worked in I worked in four different tox labs all around the world. So in the UK and New Zealand, everybody had their own way of doing things.

00:00:59

Hilary Hamnett: Um a lot of people thought that theirs was the way. So it’s very interesting when you come into contact with people who’ve only ever worked in one place. So kind of like how the things get passed down, I guess, from generation to generation. Um and it was really when I was in New Zealand that I came across this idea of cognitive bias and someone from Australia came to give a talk about it and it and it really just struck a chord with me. Um and then sort of after a while for about eight years of working in the field I came to the conclusion that it was going to be very difficult to do anything from within. Um and there’s some sort of structural reasons for that particularly in the UK where um in England and Wales labs are competing with each other for work. So we have a privatized system where um labs compete with each other for police force work. So it’s very difficult to get people to change the way they’re doing things. Um and and one of the problems with cognitive bias is that it unfortunately often makes life harder.

00:01:53

Hilary Hamnett: So you putting in processes to minimize bias don’t necessarily make things better in terms of efficiency and cost and so on. So it’s a hard sell to people who are um trying to uh you know produce really cost-ffective work to win tenders to do work with police forces. So I went out into the world of academia um and it’s really since I’ve been out there that I’ve been able to start publishing about this and um sort of talking about it a little bit more and coming in from outside rather than trying to do it from within. Um, and I’ve got a couple of uh papers where I’ve done um uh surveys. So I did a survey at TAFT in 2016. So this is the International Association of Forensic Toxicologists. They had a conference in um Brisbane in 2016. I did a survey then and I redid the survey in uh just last November when the same conference was in New Zealand again. So I’ll be hoping to publish that soon. Um I also have one where I did a little experiment with my students looking at how um cog how sort of contextual information affects decisions.

00:02:57

Hilary Hamnett: Um and then I have one in the TAF bulletin which is like a a sort of um I guess trade magazine for that organization which goes to lots of different labs about more um practical things that people can do. So in in cognitive forensics we do we like to talk a lot about the problem and I think we probably talk less about what people can actually do about it and I was I was watching um when you had it draw on your show and um and he was very kindly saying that people are you know people’s minds are changing which is great and there is a lot more acceptance um but now people are moving on to the stepper of all what can we do um and so that’s really where my work focuses now is what can we do about
Aaron Olson: Okay. Yeah, we’ll get to that. Uh what what can we do? But first, let’s define what are some of the problems that you see with cognitive bias. Like how do you define it and how does it apply to toxicology?

00:03:52

Hilary Hamnett: So cognitive bias is uh it’s a mechanism in our brains that comes about because we take mental shortcuts all the time and we don’t have any control over that. So, um, we take mental shortcuts basically to make our lives easier and it’s hardwired into us, um, to make quick decisions. Um, and a lot of the time on like a day-to-day basis, am I going to cross the road now? Um, it’s really helpful. It’s not particularly helpful in in forensic science. Um, and in forensic toxicology in particular, there are certain points in a case where they it really can become an issue. Um, so I like to talk about the the strategy. So when you decide what test you’re going to do, um there’s the actually deciding whether the drug is present is another one. Um deciding how much is there and then the final one is is the interpretation. So there’s sort of the four points in the case where I think they’re most vulnerable to cognitive bias. Um and it it’s not necessarily the same for every case.

00:04:49

Hilary Hamnett: So some cases, as I’m sure you have experienced, are are simpler than others. Some cases you have better quality evidence than others. And it’s really the cases where the evidence is ambiguous or it’s poor quality that cognitive bias plays the biggest role. So when you’ve got to make a tricky decision, that’s when the bias can start to creep
Aaron Olson: Okay.
Hilary Hamnett: in.
Aaron Olson: So you you identified the three major errors or areas uh selection of the test,
Hilary Hamnett: Mhm.
Aaron Olson: this the identification of the substance and the interpretation of the results.
Hilary Hamnett: Yep.
Aaron Olson: Of those three,
Hilary Hamnett: Yep.
Aaron Olson: where do you see the biggest uh issues with cognitive bias?
Hilary Hamnett: It’s definitely at the start because if you pick the wrong test at the start, the rest of the case you can’t really selfish it. So it and particularly if you use up all of the all of the sample for example, making a biased decision at the beginning that’s the end of the case. So getting it right to begin with is it for me is the big

00:05:42

Aaron Olson: Yeah. Yeah.
Hilary Hamnett: thing.
Aaron Olson: So many toxicologists receive case details from investigators. At what point does contextual information become helpful or hurtful in a in a case?
Hilary Hamnett: So when you’re setting up the um tests, my the advice I give to people when I because I do some bits and pieces of training around tox labs is to um have a a defined testing scheme. So I don’t know if you’re familiar with this, but say every Yeah. And you can do it by case types. You can say, well, our postmortem cases are going to have these tests done on them. our um you know alleged sexual assault is going to have this type of drivers are going to have this type of test. So you can have a sort of a scheme for broadly each type of test. Um and so when you get a driver in they just go for that set of tests and you don’t actually need to worry about what’s in the case circumstances. And so if you’re using the case circumstances to make a case-bycase decision, that’s when the problems can really begin because the the information that you receive may not actually be accurate because people don’t always tell the police the truth, right?

00:06:45

Hilary Hamnett: That won’t be a shock to anybody listening to this podcast. People aren’t always honest at the moment that something happens. People can’t remember what happened. Maybe they just say something that springs to mind. Um things like this, you know, the scene where something happens. Um, it’s typical to see something like, oh, there’s drug paraphernalia all over the place there. Maybe there are empty blister packets. They may not have anything to do with that person. So, they may be living in an environment where there are empty blister packets or um, you know, they could belong to someone else or the opposite. So, sometimes you get these cases where maybe it’s a teenager and the parents um, come in and they tidy up the scene because they don’t want that to get around that there was drug use involved. And so actually what’s at the scene may not have any relevance at all um to to the case. And so relying on that we’re on quite shaky ground um because it may not be accurate.

00:07:35

Hilary Hamnett: It may be but but it may not be. So when you start making these case by case decisions you you bring in the context from the case but you also bring in your own experiences and your own um you know well I’ve seen this before or your own stereotypes about you know who might be using drugs and who might not be. So it could be based on age, it can be based on um ethnicity, on sexuality. So there’s lots of different um I like to call them rough guides or rules of thumb that people have. Um and I asked this question in one of my papers. I did a survey and said, “How do you decide what test to do to people from all over the world?” And they all came out with a totally different rule of thumb and it was often based on age. Um so it’s better to have a defined testing scheme for each of these types of case. Of course, there’ll always going to be the exception. There always going to be the the case where somebody’s taking something unusual or, you know, you need to do an extra test and and that’s not a problem.

00:08:31

Hilary Hamnett: The you know, having the odd extra thing that you do is fine, but having a routine set of tests for everybody on case type is the best way to deal with that situation.
Aaron Olson: Can you think of any type of uh example like a concrete example where contextual information might influence the outcome or deciding on which tests are run?
Hilary Hamnett: So there’s a really interesting example by the forensic science regulator here in the UK. Um so we have a UKwide regulator. Um and they talked about an example where a case came into the lab and it was the person had a history of heroin misuse. So that was known about the person. There was a very limited blood sample which is which can be the case um you know with someone who has collapsed veins if they’ve been injection for a long period. So a really limited sample. the the choice of tests was so important to get it right so as not to use all the sample up. The um the lab decided to go straight for an opiates confirmation.

00:09:27

Hilary Hamnett: They didn’t even do you know an imunino assay to check um for opiates. They used up the whole sample and the case was negative and that was because the person had the the deceased had moved on to methadone and they hadn’t been given that information that they’d actually stopped using her when they gone on to methadone. And so that decision right at the beginning to to make you know to do that test based on the information that they had then that was the end of the case. There was no more blood. So that’s just an example of of how that can go wrong and it’s less of an issue if you do have a lot of sample you can go back and do more tests or change tests but that’s expensive and timeconuming. You know going around around doing test after test after test is timeconuming. So having getting it right first time is better whether you have a limited sample or not.
Aaron Olson: Yeah. Yeah. Um, so one of the interesting findings of one of your studies was that toxicologists were aware of co cognitive bias but they had very few formal practices and procedures around addressing it.

00:10:24

Aaron Olson: Uh, you know why do these gaps exist and what kind of you talked about proposed solutions.
Hilary Hamnett: Yeah.
Aaron Olson: What kind of things do you think about as uh shoring up those gaps of policies?
Hilary Hamnett: So I think I think the reason is that we as a field we rely very heavily on analytical chemistry. So, and that kind of gives us this idea that what we’re doing is is um objective because it’s a machine that’s giving us the answer. And I think it’s taken a while for people to sort of understand that actually there is quite a lot of subjectivity in our field. Even though we’re relying on a machine to give us an answer, what we put in the machine is subjective. You know, how we think about the results is subjective. So, I think there’s that. You know, we I think it was easier for the people who worked in things like fingerprints to see that their decisions were subjective because they had two things and they were looking at them and comparing them. And it’s been harder for us to sort of come to terms with that idea that what we do is subjective.

00:11:16

Hilary Hamnett: Um terms of things you can do. So um consistency like I mentioned before is really important. So treating cases the same, having a defined uh testing scheme up front. Transparency is really really important as well. where if you have to write down the decision and justify where you made it, you will often think twice about the decision that you made because you also have to think about that decision being disclosed to family or the other side depending on the case. And if you’re happy for them to read what you’ve written, you will make a different decision to if you can just have free reign and make whatever decision you want based on whatever stereotype you like. Um if you have to write it down, then then it’s different. And then I think um particularly at the end of the case in that when we get to that interpretation side um being clear that there can be more than one uh reasonable explanation. So we can have cases where we got the same results. You could look at it maybe two or three ways maybe and all of those explanations are plausible.

00:12:35

Hilary Hamnett: And we often will go with just one and we’ll go with the one that we think is most likely or the one that seems to fit and I hate that phrase but seems to fit with what we know about the case. And we we’re not very clear with the person reading the report that maybe there are other options. Maybe something else could have been um at play here. And uh and we’re also not great at saying I don’t know. you know, here are the options and I don’t know which one is correct and and you know, we kind of we like certainty and that’s a sort of a just human nature. You know, it not many people like to leave things hanging. Um so that side of it as well is making it clear to the person reading the report that there are other other explanations and also that you what you knew. So when you did your interpretation what you knew about the circumstance of the case because if they that then changes it’s clear to the person reading the report that maybe the interpretation is going to change as well.

00:13:28

Aaron Olson: Okay. So, thinking about that in the report and what you would put in a report, how would things like uh interpretations, would those go in the formal report or would those come up later uh during talks with prosecutors or defense attorneys? Uh you know, how would that go? How would that practically play out?
Hilary Hamnett: I think it depends on on how you do your reporting. So I know some labs um have a very kind of simple report where basically everything is just produced by a computer. You know, it’s just standard text that comes out of a computer. Um and the problem with that sort of standard text is that it can very quickly become out of date. So somebody puts it in and then people forget to update it. And also you can lose the nuance as well in it if you just have these sort of boilerplate text statements. Um so in some labs it would go in the report other labs it would be a case of saying like you know there are alternative explanations for these results please contact us and then you can talk it through with uh whoever it is whoever this whoever submitted the sample.

00:14:27

Aaron Olson: As you’ve worked in the field, how eager are laboratories uh to do this type of extra work and shield analysts from irrelevant case information or put uh you know caveats about the analytical interpretation in reports?
Hilary Hamnett: I it’s a mixed picture. I think there are some labs that are quite keen um particularly the ones where they’ve had a challenge in court. So I’ve been contacted by labs who say you know somebody went to court and they were asked what’s your bias minimizing policy? What processes did you go through? And they don’t have an answer and that really seems to focus the mind. So then people will then get in touch with me and say please can you help us um with this? So it it’s a mixed picture. Some people are quite far along, some people are really kind of beginning. there’s still people holding out, you know, there’s still people who say we just don’t accept this. Um, so but I think things are changing and when I did my survey again, I did find that there were more people who say they have a policy now.

00:15:22

Hilary Hamnett: There are more people using uh bias minimizing procedures. So things have been changing in the field and OSAC as well. So I’m involved with OSAC. We’re currently writing a document about human factors and cognitive bias in um forensic talk. So hopefully when that comes out that will give people a little bit more guidance as to what they can be
Aaron Olson: Yeah. Yeah.
Hilary Hamnett: doing.
Aaron Olson: What do you think are some of the biggest changes that you’ll we’ll see coming forward?
Hilary Hamnett: I’d like to start to see um everybody moving to defined testing and so people stopping doing this case by case uh which also helps your lab become more efficient because you don’t have to sit there and about what test to do. Um I I think a big change will be when people start writing their reports differently and they start saying you know this is information that I was given and you know there are some caveats to this and there are you know other explanations for this. I think that will be the big thing when when the court starts seeing this in the in black and white if you like um that will be the biggest change.

00:16:21

Aaron Olson: Yeah. So, you know, we’ve talked a lot about your work, the role of cognitive bias, uh, interpretation and and the testing procedures. What are some of the big ideas that I haven’t hit on yet that you think are important for people listening to consider?
Hilary Hamnett: So I think that um deciding whether a drug is actually there or not is one of the danger points in my is one of the bias zones if you like. Um because depending on how you do your workflow, you may end up looking at too mass spec and um trying to decide whether there’s a match, right? So is this actually here or not? Um, and there are some labs who are who are really transparent about it and they’ll use criteria, set criteria and they’ll they’ll apply them consistently. And there are other labs who have a it’s a match because I say it’s sort of approach. You know, they’ll sort of eyeball it and say, “Oh, yeah, that looks like a match.” Or they’ll do, you know, the opposite of what I want them to do.

00:17:13

Hilary Hamnett: And they’ll say, “Oh, this is a tricky decision. I’ll go and get the case file and I’ll read the circumstances and that will help me help me inverted to make a decision. So, you know, I’ve got this this number on my immuno assay. It’s very very close to the cutoff. Should I confirm it or not? They’ll go and get the case. Depending on the case, they’ll then make a decision to confirm it or not. And actually, what they a better thing to do is to just have a rule that if you’re close to the cutoff, you always confirm and then you never have to look at the case circumstances um because you’ve got that kind of in place. So, yeah, that subjective decision about whether something is there and then also how much is there. So um manual integration is a real danger point. Um so and this can also tends to be a problem with the iffier samples, right? So the sample is dirty, limited. You can often find that the the machine doesn’t um manually integrate it very well.

00:18:06

Hilary Hamnett: You you go in and you fiddle with the integration, suddenly that person is over a significant limit, right? So they’re over a driving limit or they’re you know it was a QC sample and now it’s in and before it was out. And so if you know what that sample is and you know that changing the integration could could have quite a significant difference that’s a problem um in terms of motivations for doing that. And actually in the UK now in England and Wales um in driver cases so we have our uh per se limits for um drugs in drivers manual integration’s banned now. So you’re just not allowed to do it and if it doesn’t integrate you have to run the sample again. Um so that’s another danger point.
Aaron Olson: Yeah. And is the manual integration banned? Was that due to the fallout of the Randox testing scandal or other
Hilary Hamnett: I mean I think that’s probably one of the reasons behind it.
Aaron Olson: reasons?
Hilary Hamnett: Um but also it it is um a problem with not just with the you know the QC’s which was a problem with randox but also with K samples as well.

00:19:07

Hilary Hamnett: So, um you just generally it’s not a good not a good thing to be doing where you’ve got a a really um important limit.
Aaron Olson: Yeah. Yeah. Well, tell me what you’re working on next. What What do you got in the
Hilary Hamnett: Yeah.
Aaron Olson: pipeline?
Hilary Hamnett: So, um I’m hoping to get my follow-up survey published to um and I’m hoping to publish that in the there’s a special issue for the um TF conference. Um, and so I’m hoping to get that published to show actually how much progress has been made because I think like it’s encouraging for me that I haven’t just been wasting my time for the last 10 years. Um, but also so people can see, you know, that this is changing and actually this, you know, this percentage of people are reporting having a policy, maybe we should get a have a policy as well. Um, and I’m always looking to work with, you know, any lab who wants to have a have a policy. I’m always on the lookout for any lab who wants to have a policy um to help them develop it. um if we can then publish the text of it. So I think one of the things that holds people back is they just don’t know where to start and so it’ be great if um you know we could get an example of one that we could publish and make publicly available and then people can use it as a starting point for their own work.
Aaron Olson: Dr. Hamnet, thanks so much for coming on the show today and sharing with us about your work. Is there anything that you want to leave listeners with before we end the call?
Hilary Hamnett: no. There is a uh another um sorry I should said yes there is a a rival podcast where I talk about this in a lot more detail which is the talk pod. Um so if anybody wants like a lot more of the nitty-gritty um then you can head over there and and hear me talk about that um in a bit more detail. Thank you.

I’m excited to share that my recent editorial, “Truth, Power, and the Crisis of Forensic Independence,” has reached the Most Downloaded list in Forensic Science International: Synergy.

It’s encouraging to see this topic resonating with so many readers in such a short time.

In this piece, I examine the structural tension between scientific independence and institutional loyalty in forensic laboratories operating within law enforcement hierarchies.

The article explores documented cases in which forensic professionals who challenged prosecutorial narratives or exposed systemic issues faced retaliation or marginalization.

I argue that these are not isolated incidents, but symptoms of a deeper governance problem. True scientific integrity requires independence from institutional pressure, full disclosure practices, meaningful external oversight, and real protections for whistleblowers.

Forensic science cannot claim objectivity while remaining structurally dependent on the very authorities it is supposed to scrutinize.

If we want public trust, we must be willing to examine the systems that shape our conclusions.

You can read the full open-access article here:
https://doi.org/10.1016/j.fsisyn.2025.100647

I appreciate everyone who has taken the time to read, download, and engage with the work. The conversation around forensic independence is not always comfortable, but it is necessary.

PS - I also encourage you to read the recent paper by , about how forensic knowledge is captured within the institutional framework of today’s policing profession: https://www.sciencedirect.com/science/article/pii/S2589871X26000057

Last week, I presented at the American Academy of Forensic Sciences in New Orleans, LA.

I presented on a topic that sits at the foundation of forensic science: how laboratory errors happen and why full discovery is essential to preventing them.

I examined and documented toxicology failures and categorized recurring error patterns, including calibration failures, traceability breakdowns, discovery violations, source code defects, contamination, reporting errors, and even fraud.

Several themes stood out.

First, many errors persisted for years or decades before detection. A 14-year breath alcohol miscalibration in Washington, DC is one example. Other method and software defects survived multiple accreditation cycles.

Second, major failures were often uncovered by outside parties, new employees, or whistleblowers rather than internal quality systems. Institutional resistance to disclosure frequently delays correction.

Third, technical competence alone is not enough. Culture, transparency, and oversight are just as critical as analytical skill.

I outlined practical reforms, including mandatory online discovery portals, preservation of digital data and metadata, independent oversight, whistleblower protections, and regular third-party audits.

The takeaway is simple: If these vulnerabilities existed elsewhere, they likely exist in other jurisdictions today.

Forensic science earns public trust through accountability and transparency.

You can read the full analysis in my published article here: https://www.sciencedirect.com/science/article/pii/S2589871X25000580

Yesterday, the Minnesota Supreme Court heard oral arguments in Knapp v. Commissioner of Public Safety. This case goes to the heart of how courts treat scientific evidence in breath alcohol testing.

At issue was not whether breath testing is generally reliable, but whether a foundational scientific safeguard, the pre-test observation period, must actually be followed for a test result to be admissible.

In other words:
Is it enough that an officer holds a certificate, or must the officer actually follow the procedures that make the test scientifically reliable?

The Observation Period as a Necessary Scientific Safeguard

Breath alcohol testing is designed to measure alcohol coming from the lungs. Alcohol originating from the mouth, whether from burping, regurgitation, reflux, or recent ingestion, is contamination of the breath sample.

The observation period exists to address that problem.

This requirement is clearly stated in the current and previous versions of the DataMaster DMT Operator Training Manual:

“A test subject should be observed for a minimum of 15 minutes prior to administering a breath test to ensure nothing is placed in the mouth and nothing erupts into the mouth.”

The Astrology Hypothetical and Why It Mattered

One of the most revealing moments in the hearing came when a justice posed a hypothetical that crystallized the Court’s unease with the State’s position:

“So the legislature could legislate complete bunk science. It could say an astrological test is per se admissible as long as the astrological test is certified by the commissioner of astrology.”

Astrology is inadmissible not because a statute fails to mention it, but because it lacks scientific reliability.

Should Breath Tests Have an Evidential Carve-Out?

Throughout the arguments, multiple justices questioned why breath tests should be treated differently from other forms of scientific evidence.

In DNA analysis, contaminated samples are excluded. In blood testing, improper collection invalidates results. In fingerprint analysis, flawed procedures undermine admissibility.

In none of these fields do courts say, “The analyst was trained, so the result comes in regardless.”

The State argued that breath tests should be admitted based solely on the operator’s certification and the instrument’s internal checks.

Several justices found that position difficult to reconcile with general evidentiary principles.

Training Versus Credentials

Another theme that emerged was the distinction between having training and following training.

A lab technician who ignores contamination safeguards does not produce valid results simply because they passed a certification exam years earlier.

The observation period is the primary human safeguard in an otherwise automated process. Treating it as optional strips the test of one of the test's basic scientific safeguards.

Remand and the Court’s Broader Concern

Multiple justices suggested that the case might ultimately be resolved through remand, allowing lower courts to apply a more traditional rules-of-evidence analysis rather than the rigid burden-shifting framework that has developed in implied consent cases.

The Question That Remains

At bottom, Knapp asks a simple question:

If a procedure is required to make a scientific test reliable, can courts admit the result when that procedure is not meaningfully followed?

Or does the failure to follow scientific procedures merely go to the weight and persuasiveness of that piece of evidence?

In a recent webinar for the International Association of Forensic Toxicology Consultants, nationally recognized DUI expert Josh Ott delivered a comprehensive analysis of Standardized Field Sobriety Tests (SFSTs) that challenges common assumptions about these roadside evaluations.

Drawing on over a decade of experience conducting thousands of DUI investigations as a law enforcement officer and his current work providing expert testimony, Ott examined the actual research behind field sobriety testing and revealed troubling gaps between what officers are taught and what the science actually shows.

The Fundamental Misunderstanding

Perhaps the most critical point Ott emphasizes is that field sobriety tests were never designed to measure impairment. This statement contradicts what officers testify to in courtrooms across America every day.

The tests were developed and validated solely for one purpose: to discriminate between drivers at or above the legal BAC limit from those below it. They have never been studied for their ability to measure driving impairment, drug impairment, or even alcohol impairment itself.

As Ott notes, “I would say probably throughout the United States right now, officers are testifying in court they observed X number of validated clues of impairment for each of these tests. And that ends up being a very big problem.”

The Development and Validation Studies

The standardized field sobriety tests emerged from research conducted by the Southern California Research Institute with funding from NHTSA starting in 1975. Three major tests were identified as most accurate:

• Horizontal Gaze Nystagmus (HGN)

• Walk and Turn

• One Leg Stand

However, Ott points out a concerning pattern: Dr. Marcelline Burns authored five of the six major studies used to develop and validate these tests. This concentration of authorship raises questions about independent verification of the research.

The San Diego Study: What Officers Don’t Learn

The 1998 San Diego field validation study is the most commonly cited research when officers testify about SFST accuracy. Officers learn that the tests showed 91% overall accuracy, with HGN at 88% accurate, Walk and Turn at 79% accurate, and One Leg Stand at 83% accurate.

What they don’t learn is equally important.

The False Positive Problem

Ott calculated false positive rates that were never published in the study itself:

• HGN: 37% false positive rate (one in three people below 0.08 showed 4+ clues)

• Walk and Turn: 52% false positive rate (statistically equivalent to flipping a coin)

• One Leg Stand: 41% false positive rate (nearly the same as guessing)

• Overall arrest decision: 28% false positive rate (more than one in four drivers incorrectly arrested)

To calculate these rates, you have to dig into the raw data matrices provided in the study. They are not prominently featured in the conclusions.

Study Design Concerns

Several aspects of the San Diego study raise red flags:

1. Sample characteristics: Of 297 drivers in the study, only ONE refused chemical testing (less than 1%). In actual practice, refusal rates are typically around 50%. This extreme compliance suggests the sample may not be representative.

2. BAC distribution: The average BAC of arrested drivers was 0.15%, while non-arrested drivers averaged below 0.05%. This wide separation makes discrimination easier. The tests were supposedly validated at 0.08%, but most subjects were far from that threshold.

3. PBT influence: Officers had access to preliminary breath tests. While NHTSA assures us officers recorded their estimates before viewing PBT results, the data raises questions. Of 30 people who were false positives on HGN, only 16 were actually arrested. Why would officers disregard what they’ve been trained is a “silver bullet” test in nearly 50% of cases?

The Training Disconnect

Perhaps most troubling is what officers are taught about errors. The ARIDE instructor manual tells officers that “research has demonstrated that officers are more likely to err on behalf of the defendant.”

The actual data from San Diego shows exactly the opposite. There were 24 false positives compared to only 4 false negatives—making false positives 14 times more likely than false negatives. Officers are trained to believe the opposite of what the research actually demonstrates.

The Robustness Study: Changing the Rules

In 2007, Dr. Burns published the “Robustness of the Horizontal Gaze Nystagmus Test” study, funded by NHTSA. The purpose was to address defense arguments that incorrect administration compromises HGN accuracy.

Shocking False Positive Rates

When HGN was administered correctly:

• 67% false positive rate at BAC < 0.08 (two out of three people)

• 65% false positive rate at BAC < 0.05

• 85% false positive rate at BAC < 0.03

When administered incorrectly:

• Stimulus too high: 91% false positive rate

• Stimulus too low: 79% false positive rate

• Stimulus too close: 92% false positive rate

• Stimulus too far: 84% false positive rate

Despite these extraordinarily high false positive rates, Dr. Burns concluded that HGN is a “robust procedure,” meaning administration variations don’t compromise accuracy.

The Standard That Never Was

How did Dr. Burns reach this conclusion with such damning data? Ott discovered she had changed the validation standard.

Since the 1998 San Diego study, the criterion has been that 4+ clues on HGN indicate a BAC of 0.08 or higher. Dr. Burns taught this standard to officers herself.

But in the robustness study, she stated that the criteria “as defined in the SFST curriculum” were that 4 clues indicate a BAC of 0.03 or higher, a standard that has never appeared in any SFST curriculum.

By lowering the threshold from 0.08 to 0.03, she dramatically reduced the number of results classified as false positives. As Ott states, “Dr. Burns took her opinions and then took the data and changed the standard to make it fit her opinions instead of taking the data, applying the correct standard and forming her opinions on that.”

The DRE Technical Advisory Panel later retracted this study from their manuals, though it has not been officially retracted.

The JAMA Study: Sober People Fail These Tests

The 2023 Journal of the American Medical Association study on field sobriety tests and cannabis provides crucial data: it included a placebo-dosed control group, allowing researchers to see how completely sober people perform on these tests.

Participants were marijuana users who were screened physically and mentally, tested for drugs and alcohol on the study day, and performed on a driving simulator before receiving placebo doses. There was no evidence of residual effects from prior marijuana use.

Results for the 63 placebo-dosed (sober) individuals:

• Walk and Turn: 56% false positive rate

• One Leg Stand: 37% false positive rate

• Combined: 28% false positive rate

More than one in four completely sober people were deemed impaired based on these tests. These rates closely match the San Diego study findings.

What This Means for the Courts

The implications of this research are profound:

1. These tests were never validated for impairment. The San Diego study explicitly states, “the only appropriate criteria and measure to assess the accuracy of the standardized field sobriety test is BAC, and measures of impairment are irrelevant.”

2. False positive rates are substantial and largely unknown. Officers receive no training on false positive rates, and even if they read the studies, the rates aren’t published in the conclusions.

3. Officers are trained incorrectly about error direction. They’re told errors favor defendants when the data shows false positives far exceed false negatives.

4. The peer review problem. The San Diego study has never been peer reviewed, yet it’s used to satisfy Daubert or Frye standards. A paper about the study was peer reviewed, but not the study itself.

5. Not all officers are equal. A boating under the influence study found that 20% of experienced officers with an average of nearly 10 years administering SFSTs were less than 50% accurate with HGN. Yet courts treat all officers as equally reliable.

Critical Knowledge Gaps

Ott identifies several factors that have never been properly studied:

• Age effects: A 21-year-old and a 64-year-old are evaluated identically, despite obvious differences in balance and physical ability

• Weather conditions: Despite claims that these tests work in any conditions, no controlled studies exist

• Surface conditions: The impact of uneven surfaces, grades, or different materials hasn’t been systematically studied

• Footwear: Tennis shoes versus flip-flops versus heels versus barefoot

• Injuries and medical conditions: Beyond basic exclusions, the impact hasn’t been quantified

The Challenge Ahead

As Ott notes, “If you tell a lie long enough, it becomes the truth.”

The belief that field sobriety tests measure impairment is so deeply ingrained in the criminal justice system that challenging it faces enormous resistance.

Every day, officers testify that these tests indicate impairment. Prosecutors rely on this testimony. Judges accept it. Even many defense attorneys believe it.

The uphill battle is not just about correcting the science; it’s about overcoming decades of institutional momentum.

Josh Ott is a nationally recognized expert in DUI investigations and SFST administration with over a decade of law enforcement experience. He currently works with Case Lock Incorporated, providing expert testimony and case review services in alcohol and drug impairment cases.

The International Association of Forensic Toxicology Consultants hosts monthly webinars on topics relevant to forensic toxicology. For more information about upcoming presentations, visit iaftc.org.

Clips

Related podcasts

• The Accuracy of Standardized Field Sobriety Testing (SFST) with Dr. Greg Kane

• Challenging the Validity of SFSTs and Drug Recognition Testing with David Rosenbloom

• Are Standardized Field Sobriety Tests (SFSTs) Scientific? - Josh Ott

• The Eyes Have It (Wrong): Horizontal Gaze Nystagmus Through an Ophthalmologist’s Skeptical Lens

Transcript (automated - not checked for errors)

[00:00:00] Introduction and Speaker Background

Aaron Olson: today we’ve got. Josh Ott, he’s gonna present to us about , field sobriety testing and his work that he’s been doing on this. He’s a nationally recognized expert in DUI Investigations, SFST administration, HGN Interpretation, and he draws on more than a decade of experience at the Roswell, Georgia Police Department.

He’s conducted literally thousands of DUI investigations. He served as a drug recognition expert, instructor, and trained. Officers across multiple disciplines and jurisdictions. His background includes work in the motor and traffic enforcement unit, investigation for serious injury and fatality collisions along, and he’s also received numerous awards for his contributions today.

He works for Case Lock Incorporated and provides expert testimony and case review services and alcohol and drug impairment cases. Josh, thanks so much for doing this for us today.

Joshua Ott: Well, thanks for the invite. Good afternoon everyone. So if anyone has any questions as we go, just feel free to unmute your, um, video and, and immediately ask the question so we can address it at, at that time.

[00:01:06] Purpose and Importance of Standardized Field Sobriety Tests

Joshua Ott: But what we’re gonna be talking about. Are the studies that have been conducted into the standardized field sobriety test. And some of the topics we’re gonna address is the purpose, the development and validation.

And the three major studies that we’re gonna focus in on are the San Diego study, the Robustness of the Horizontal Gaze Nystagmus Test Study, and the recent um, 2023 Journal of American Medical Association study. So what is the purpose of the standardized field sobriety test? Number one is to have standardized tests.

And this is important because we want all officers administering and interpreting tests the same way across the United States. So ultimately, when we watch a video, if we’re being objective with it, we can determine, number one, that the officer administer the test correctly. Number two. Did the, how did the defendant actually perform on the test so we can interpret it for ourselves and say, on the walk and turn, we did see two or more clues.

And then by having them validated, we now know how accurate and accurate the test is supposed to be and what the results actually indicate to us. These are intended to be screening tests, so they’re obviously used in court well beyond the scope of what they were intended for, but they were intended for helping an officer determine whether or not they should make an arrest based on the standard of probable cause.

And so for that purpose, in my opinion, these tests are absolutely beneficial because if we looked at a normal DUI investigation between vehicle motion and personal contact, when the officer’s first making contact with the driver, probably within about 30 seconds, in majority of investigations, the officer already has probable.

And so without having any of these tests, a lot more drivers would be going to jail than what ends up happening after the test. Because there are numerous drivers who initially, the officer suspects that their DUI, they administer the field sobriety test and ultimately the officer determines they should not be arrested.

And in my personal experience, about 50% of the people I did field sobriety on. We’re not charged with DUI. So for that aspect, these tests are beneficial. But when we get and look at what these tests have been validated for, at least according to Nitsa, and then the false positive rates of these tests, I think we’re all going to agree that to use these tests to determine or show or prove whether or not someone is not is or is not impaired, the research just doesn’t back up that purpose for them.

Then lastly, and this is very important to understand, these tests have only been studied for their ability to discriminate if a driver is at or above the legal limit from those who are below. They have never been designed or studied for their ability to measure driving impairment. Drug impairment or even alcohol impairment, which is a very common incorrect assumption and belief about these tests.

And I would say, you know, probably throughout the United States right now, officers are testifying in court. They, they observed X number of validated clues of impairment for each of these tests. And that ends up being a very big problem. And I, I say it’s one of those things that if you tell a lie long enough, it becomes the truth.

And that’s the uphill battle that all of us as experts are really facing with these tests is that. Judges, prosecutors, law enforcement officers, even defense attorneys a lot of times believe that these tests indicate impairment when that’s absolutely not the case.

[00:04:51] Development and Validation of Sobriety Tests

Joshua Ott: So let’s talk about the overview of the development and validation of these tests.

So prior to the early 1970s, there were no standardized tests for officers to use to help them determine whether or not they should arrest a driver for DUI. So what was occurring was officers were using many different tests. There was no standardization for the instructions or the clues that they were using.

And on top of that, and probably most importantly, there was no validation of those tests. So it means that it is unknown as to how accurate or inaccurate the tests were. So one of the problems that would occur is that when they went to court, judges and juries had no idea how much weight to give to the test.

So starting in 1975, the Southern California Research Institute with funding from the National Highway Traffic Safety Administration, nitsa. Decided to look into which of the test officers were using were the most accurate, and they ended up releasing three final reports. So the first report is the 1977, which was a lab study only, and this is the report that ultimately determined that the three most accurate tests were what was labeled as alcohol Gaze nystagmus.

Now it’s been changed to horizontal gaze nystagmus. The walk and turn and one leg stand. As you can see, the false positive rate of this study was 27%. And all three of these studies that we’re gonna be talking about were dealing with a 0.1 BAC, which was the legal limit throughout the United States at that time period.

And then we had two additional studies that occurred after they created the standardization for the instructions and the clues for the test. The first one was 1981, which was a lab and field study. As you can see, the false positive rate in the lab with placebo dosed individuals was 18%. So one out of every five placebo dosed individuals was incorrectly identified as being a 0.1 or higher in the study.

And then the last study was the 1983, which was a field study only. And this one, I was never able to see and calculate what the actual false positive rate was. All I can tell you is that that 94% of the officer’s incorrect decisions were false positive. So if an officer made a mistake in this study or made an error, it was going to be a likely a false.

A couple additional things I wanna point out with these studies, we’re not gonna go into the weeds with them, is that Dr. Marline Burns authored both the 77 and 81 um, study. So she was one of the authors on both of those studies. She did not author the 83 study. And this is gonna become a very important theme as we go through these tests and studies and get specifically into the robustness of the horizontal Gaze Nystagmus test study.

So what the original data found is that when four or more clues observed on HGN, it was 77% accurate, that the person was a 0.1 or higher. When two or more clues on the walk and turn was observed, it was 68% accurate, that the person was a 0.1 or higher, and two or more clues on the one leg stand was 65% accurate, that the person was a 0.1 or higher.

So this is the original data that they came out with for these tests. Now with all of those original studies, it was inexperienced officers that were being used. Obviously you can’t have an experienced officer if you just created these tests. So now in the nineties we have officers with a decade or more experience administering the field sobriety test.

So at that point, they wanted to do large field validation studies to determine if with experienced officers. These tests were just as accurate in the field as what they were in the laboratory.

[00:08:37] Key Studies and Their Findings

Joshua Ott: So the first study occurred in Colorado in 1995. The second study was in Florida in 1997, and the third study was in San Diego in 1998.

Now just briefly talk about the Colorado study. This one was again dealing with a 0.1 BAC, but in NHTSA’s insanity. The Colorado has a law where it’s driving while impaired if you’re a 0.05 or above. So even though it was to validate the test at a 0.1 threshold, if the officers arrested you and you were anywhere from a 0.05 and above, it was considered a correct arrest decision.

So ultimately it, it is just showing to me a, a lack of, um, not being biased in the study and trying to just validate these tests by lowering the threshold as to what was a correct decision versus what was an incorrect decision when you lower it to a 0.05, but are validating it. 4.1, the Florida study was the first study deal with a 0.08 BAC.

And then the San Diego study was also dealing with a 0.08 BAC. Additionally, all three of these studies were authored by Dr. Marcelline Burns. So of the six studies that were used to develop and validate the field sobriety test, Dr. Marcelline Burns was an author on five out of the six studies. So before we get into the actual data from these last studies, we have to understand what constitutes a correct.

Versus incorrect arrest decision, and this isn’t gonna be correct, as in what is, um, legally justified. So was there probable cause or not? That doesn’t apply here. We all know that you could be below the legal limit and an officer can arrest you for being less safe, and it’s ultimately a correct decision.

But for the the validation studies, what constituted a correct arrest decision was number one, the top left box. If the person was at or above the legal limit and the officer arrested them, that’s obviously correct. That’s what we want to occur. A person that’s supposed to go to jail goes to jail, bottom right.

This is a person who is below the legal limit and the officer releases them. That is also a correct decision. Stop, right, is a false negative. So this is a person who is at or above the legal limit should go to jail, but the officer incorrectly lets them go. In my opinion, these are things, these are the people that we absolutely do not want to have happen on the side of the road.

‘cause you don’t want the officer to suspect somebody’s DUI investigate them for DUI let them go. And worst case scenario, the person drives down the road and kills somebody after they’d already been investigated for DUI. So we don’t want false negatives on the side of the road. Now, bottom left. We also don’t want these on the side of the road, but it’s better to have them on the side of the road than having false negatives, but we absolutely do not, and in my opinion, in United States of America cannot have false positives in court.

We can’t have innocent people being convicted. Of a crime they did not commit. So these are people that were below the legal limit and were incorrectly arrested by the officer. So again, as we can see, the correct decisions come down solely to what the person’s BAC is.

[00:12:07] Understanding False Positives and Test Accuracy

Joshua Ott: What is a false positive? It is a test that incorrectly indicates a condition exists when it actually does not.

An easy way that I explain this is if you went to the doctor. The doctor tested you for a disease and the test came back and said that you have the disease, but in reality you don’t. That will be considered a false positive. So the last thing I wanna discuss before we get into the actual studies is understanding how false positives are calculated, because one of the things that you’ll see nitsa rely on is the overall accuracy of a test.

And in my opinion, this can be a very, very misleading statistic. So what we’re gonna have is a hundred people who are going to the doctor to get tested for a disease outta these a hundred people, 99 of ‘em actually have the disease, all 99 test positive for the disease. So the correct positive rate for this test is 100%.

It got it right on 99 out of 99 people. Now the last person does not have the disease, but they also test positive for the disease. Test was wrong on one out of one people. So the false positive rate is 100%, but the overall accuracy rate of this test was right on 99 out of of a hundred people. So it is 99% accurate overall.

And so if a doctor gave you this test and said, Hey, you just tested positive for this disease, and the test is 99% accurate. You’re gonna be scared because you’re like, oh my God, I just positively was positive for this disease. But then if you actually looked at the data, what it would tell you is that this test cannot discriminate anything.

It comes down to the whole idea of even a broken clock is right twice a day. That regardless of what the person’s condition is, the test is always going to be positive. Now, obviously this is a very small sample size, but if we blew up the sample size and had, let’s say, 10,000 people and we ran the exact same numbers, we realized that this test is absolutely worthless.

So that ultimately is, is showing the problems with, talk about the overall accuracy of a test because it can be very misleading and to me. What we should be focused on is what is important. So in, in my opinion, when we’re talking about beyond a reasonable doubt, we should be worried about what is the false positive rate of this test.

So how often is the test incorrectly indicating that a person is at 0.08 or above? But in reality, they’re actually below that level. That’s what I think we should be focused in on. So now let’s get into the Colorado Field validation study. So again, this is the first full study using experienced officers.

Now the officers were 86% correct in their arrest release decision based on the field sobriety test. Again, that is using the threshold of 0.05 BAC. 93% of the people arrested had a BAC of 0.05. This is exactly the only information the officers received about this study, and according to the actual SFST training, here’s some additional information they don’t learn about.

Number one, the false positive rate was 24%. So one out of every four people below a 0.05 was a false positive in this study, which I, I believe is a significant false positive, especially at that low of A BAC. Now, additionally, the only time that you really might hear about this study mentioned. Is if a defense attorney is making an argument of that, the, the weather conditions that the walk and turn and one leg stand were performing were issues, or the surface was a grade or it wasn’t a smooth flat surface, things like that.

Well, one of the things that I remember teaching officers when I was training them was that if you can do field sobriety in Colorado. Where can’t you do it? Because the way I picture Colorado is I imagine, you know, mountains, snow, windy, cold conditions. So like, you know, if, if you can do the test there, where can’t you do it?

And that’s really the information that the, um, authors of this study proposed with the test is that they said that, you know, there was really no effect that the weather or the surface conditions had. But the problem is, is they did not do any controls. So to make that statement, you actually have to have data and science and research behind it.

So what I believe should have occurred is you have the person do the test in a perfectly controlled environment, and now take them to a bad environment of, you know, snow cold. On level surface, things like that, and compare the results of the test. So in the controlled environment, we had zero clues out in the field.

We had two clues. Obviously the field had an effect on the test, or if there were zero clues in the controlled environment and zero clues in the field, then yes, there was no impact. But again, this is one of those times where Nitsa makes statements without any science data or research to actually back it up.

Next study, um, is the Florida Field Validation Study. You really don’t hear about this one at all, but ultimately, the officers were 95% correct in their arrest decisions. This was the first study dealing with a, b, a C of 0.08 or an above. The false positive rate of this study, which officers also do not learn about was 18%.

So basically one out of every five people that could be a false positive was. And if you notice, the common theme here is the false positive rate is usually running about 20% or above For all of the studies that we’ve so far mentioned.

[00:18:02] Detailed Analysis of the San Diego Study

Joshua Ott: And then the last study, which is the most important, and the reason that this is the most important study is because if an officer is testifying about the accuracy of the standardized field sobriety test, it is almost guaranteed that this is the study that they are testifying about.

Every so often you might hear an officer testifying to the original numbers, um, but the new training. Has been out for so long that, um, they started really hammering into the San Diego study in the 2013 manual back in the 2000, um, sick manual. It was addressed but not as harshly and and as much as it is now.

So basically, you’re almost always gonna hear officers referencing the study. Overall officers were 91% correct in their arrest decisions. Now, this doesn’t mean that if you take HGN walk and turn and one leg stand and add them together, that it’s 91% accurate. What this means is that when the officers got to the end where they made their decision of whether or not to arrest the person, whatever they based that arrest decision on, they were ultimately right 91% of the time.

And then also this study stated that HGN is the most accurate of the three standardized field sobriety tests. The last information that they provide officers about this study is that they break down the accuracy of each one of the tests. So for HGN, the criterion was still four more clues, but now it would indicate a 0.08 or higher.

So using that, it was 88% accurate. Walk and turn and one leg stand. It was still two or more clues on each of the tests, but they would now indicate 8.08 or higher. And walk and turn was 79% accurate and one leg stand was 83% accurate. So now let’s dig into the study, and this is the information that officers don’t learn about with the study is number one that they used seven officers from the San Diego Police Department’s Alcohol Enforcement Unit.

And to my understanding, this is basically their DUI task force. These officers are already trained and experienced and administering the field sobriety test. But even with that, they received a four hour refresher course. Again, it was taught by Dr. Burns who, number one, is making sure that the officers are administering the test correctly.

‘cause that’s a very important key to these tests. They have to be administered correctly. Number two is she was teaching them the new criteria for the test. That the clues on HGM walk and turn in one leg stand instead of indicating a 0.1 or higher would now indicate a 0.08 or higher. So again, when we get into the the robustness study, remember that it’s Dr.

Burns who’s the one that actually teaching the officers that the standard is four more clues, indicates a 0.08 or higher. That’s gonna be very important and relevant. Now after they received this four hour refresher course for the next several months, the officers who were involved in the study went out and made traffic stops on the general public.

So they were doing the same thing A DUI task force officer does on a normal night of looking for DUIs. If they observed any objective signs that the driver had consumed alcohol, they were to administer the three standardized field sobriety test on them. They didn’t have to observe any indicators of possible impairment, just that the person had consumed alcohol, and so they were only able to administer the three standardized field sobriety test.

No other test as well. So now let’s dig into the numbers. So number one is that there was a total of 297 drivers involved in the final data of this study. There was one additional driver who was initially involved in the study, but they were removed because they refused to submit to any chemical testing.

Now, in my opinion, that’s an absolute correct decision by the auth authors because if we’re determining the accuracy of these tests based on the person’s BAC, then we have to know what the person’s BAC is. So that’s not an issue. Here’s where the issue is, and this is my first red flag of this study, and there are many, but there are almost 300 drivers involved and only one, one.

Refuse to submit to any chemical testing that is a percentage less than. 1% of drivers refuse chemical testing. Now, in my experience, both as a law enforcement officer and now being an expert, I would say it’s around 50% of drivers refuse to submit to the chemical test. So this is one of those times where you immediately just raise your eyebrows and say, this doesn’t match up.

How did they get that many drivers to consent to testing? And these are people legitimately being arrested for DUI. This isn’t one of those studies where. NHTSA says that, um, if you blow over, we’re not arresting you. You know, the roadside studies, things like that. These are people legitimately being arrested for DUI.

Now, additionally, of the 297 drivers, their average BAC was a 0.12 of the drivers arrested. Their average BAC was a 0.15, and if the driver’s not arrested, their average BAC was below a 0.05. The reason that I’m bringing up all of these numbers is because we are trying to validate the test at their ability to discriminate who is at or above this threshold of 0.08 from those who are below it.

And so it stands to reason that the further a person gets away from this line, the easier we would expect the officer’s arrest decision to become. So let’s take a person with a 0.15 B, a c, almost two times the legal limit. There’s a good chance that this person is showing gross signs of intoxication, of slurred speech, unsteadiness, staggering, things like that, that before the officer ever gets into the field sobriety test, they’re already suspecting that, or maybe they already know that they’re arresting this driver for DUI.

And then we do the the field sobriety test, and lo and behold, the person gets arrested or on the other side of the coin. We have the person who is below a almost half the legal limit. Maybe the only thing that they’re showing is an odor of an alcoholic beverage. So before the officer administers the field sobriety test, they already highly suspect that they are not arresting this driver for DUI.

And this is a big additional issue with not just this study, but almost all of the studies that have been conducted in the field sobriety test is that the wide range of Bacs likely makes it easy on the officer’s arrest decision. And so what I believe would occur is if we took the people and had them between a 0.06 and a 0.1, the overall accuracy that occurred in this study would drastically lower because in my experience, that is the hardest area for an officer to be able to discriminate between of people that are, are of that very marginal BAC limit of are they slightly over or are they slightly under now?

What were the false positive rates for the San Diego study? For HGN, it was 37%. This means that one out of every three drivers, um, who was below a 0.08 had four more clues, walk and turn. It was 52%. So this means that if you were below a 0.08, it would be statistically more accurate for an officer. Flip a coin as to administering that test.

One leg stand, 41% false positive rate. So again, it’s almost as statistically accurate for an officer to flip a coin as to administering that test. And then lastly, when the officers made their ultimate arrest decision, the false positive rate was 28%. So this means that more than one out of every four drivers, who based on the parameters of this study, should not have been arrested, were incorrectly arrested by the officers.

Now. Additionally, officers did have access to PVTs, but NITSA basically assures us that these PVTs did not impact the officer’s opinions. Now, how they assured that is that they had officers fill out this form. And so as you look at the form, what you can see is that there happened a list, how many, many clues they observed on each one of the tests as they’re doing it, and then.

We get to number four where the officer then has to write the estimate of the person’s b, a, c, and then below that they write the time of the estimation. Then we get to number five, and number five is where they write the the PBT result and the time of the PBT result. So by ensuring that the time listed on number four was before the time listed on number five, that’s how we assured that officers did not use the PBT to impact their opinions whatsoever.

To me, that’s just insane because. To trust the fact that officers could not have fudged the numbers and used the PBT looked at their watch, said it’s 1215 and then written 1214 for the estimation, um, is putting a whole lot of trust in the officers. And now let’s look at the data. That definitely brings questions into this.

And so what we have is on HGN, there were 30 people who were false positives on that test. Now in the study they addressed that. Officers mentioned that HGN was the silver bullet, and I know I was trained and I trained other officers that the eyes never lie. The eyes are the window of the sole. And I, as well as other officers put a lot of weight on HGN to make their arrest decision.

Of these 30 people, the HGN is telling officers to arrest, how many were actually arrested? Only 16, almost 50% of the people that HGN is telling officers to arrest for some reason were not arrested. Now, is it possible that these people did perfect on the walk and turn and one-leg stand and the officer just had doubts about it?

Yes. That’s absolutely possible. To have that occur on almost 50% of the cases is definitely questionable. And if ultimately, and even just one case, the officer used a PBT to influence their opinion, it compromises the data of the whole study. Now, on top of that, it also makes us question, was it possible that there were even more than 30 false positives and the officers used the PBT and after getting a PBT result.

Wrote that they observed two clues on HGN or zero clues on HGN. This is, again, something we will never know, but like I said, the data definitely brings questions into if the PVTs impacted the officer’s opinions. Now, what are officers taught about the false positive rates from the San Diego? And all the studies in general.

So number one, yes, they are taught that false positives do occur, but they’re not taught what the rate of false positives are. And even if the officer went above and beyond their training and actually read the San Diego study, which is not required reading, they would still not learn what the false positive rate is because it’s not actually published in the study.

[00:29:25] Understanding False Positive Rates

Joshua Ott: The only way to determine the false positive rate is for the officer to take. The matrixes that they provided in the study with the raw data and calculate the false positive rate for themselves. So number one, they would have to understand how to calculate a false positive rate. Number two, they would have to really ultimately question what they’ve been taught and say, Hey, I just wanna see these numbers for myself and go above and beyond and do that.

[00:29:52] Misleading Training in ARIDE Manual

Joshua Ott: But here’s where it becomes the, the biggest problem of all is that in the ARIDE instructor manual. This box right there at the bottom that I have highlighted, it teaches officers that research has, um, demonstrated that officers are more likely to err on behalf of the defendant. So ultimately, what they’re teaching officers is that if an error occurs with these tests, it is most likely going to be you letting somebody go who should have been arrested versus incorrectly arresting somebody that should have been released.

Let’s look at what the data actually says.

[00:30:28] San Diego Study Data Analysis

Joshua Ott: So this comes from the San Diego study. This is the, the box actually dealing with the, um, overall estimate of the person’s BAC by the officer. So this is the officer’s ultimate arrest decision. So what we see is that there was 214 drivers involved in the study who had a, b, a, C of 0.08 or above.

Out of those 214, only four of them were not arrested. Which gives us a false not negative rate of 1.9. Let’s call it 2%, so 2% false negative rate. In the San Diego study, 83 people in the study were below a 0.08. Out of those 83, 24 of them were false positives. That gives us a false positive rate of 28.9%.

So ultimately. It shows that it is 14 times more likely that a false positive is going to occur than a false negative, and officers are trained the exact opposite thing. So this obviously we can see the snowball effect that this has, that an officer standing on the side of the road. They know that they’ve been taught, Hey, if these tests get it wrong, it’s going to get it wrong to the benefit of the the violator.

So I have leeway on this test that, Hey, the test is telling me to arrest the person. It’s not going to be wrong that way. So I’m going to go ahead and arrest. And the reality is, it is clear that false positives, far outpace false negatives. Additionally, like we’ve already stated, the sssts are not validated for impairment.

The San Diego study makes this very, very clear. It states that the only appropriate criteria and measure to assess the accuracy of the standardized field sobriety test is BAC, and measures of impairment are irrelevant because the test must be correlated with BAC rather than driving performance.

[00:32:24] HGN Test Validity Issues

Joshua Ott: It also talks about HGN having a lack of face validity, which means that HGN is not related to actually needing to operate a vehicle safely.

And it states that, um, that is not the purpose of the test. The purpose of the test is to, again, discriminate who is at or above the legal limit from those who are below. And then additionally, it again says that it is, um. Lacks face validity because it’s not required to operate a vehicle safely. And it’s saying that that reasoning is correct that they are in this study saying that HGN is not a requirement of operating a vehicle safely, but.

It is based on the incorrect assumption that that’s what the tests are designed to measure. It is very clear throughout this study that these tests are not validated for impairment and yet every single day, like I said, officers are in court testifying to the exact opposite, and now I’m starting to see officers testifying that horizontal gaze nystagmus doesn’t just indicate impairment.

It actually is impairment. There is absolutely no research that they have to back up those statements. And the research that they’re, they’re using for these tests in general actually says the exact opposite is that HGN is not required to operate a vehicle safely. And these are the problems is that officers are able to basically get away with this testimony.

Um. Number one, because I, I don’t think judges understand how to truly gate keep this information. But number two is that the lie has been told for so long that everyone thinks that it’s the truth that these tests indicate impairment. So this is the official name of the San Diego study. So it’s the validation of the standardized field sobriety test battery at Bacs below 0.1%.

[00:34:15] Peer Review and Credibility Concerns

Joshua Ott: Number one is this is not peer reviewed. The San Diego study has never been peer reviewed, which brings a serious question into why is this study then utilized to justify the standardized field sobriety test for a Dalbert standard or a fry standard when it has no peer reviewed to it. But there is a stu, oh, there is a paper written about the San Diego study that has been peer reviewed, and the name of that paper is what you see written below.

And if you look at that and you look at it quickly and you don’t truly compare the official name of the San Diego study in this paper, they look exactly the same, or at least they sound the same. And so I think that this confusion has led a lot of people to believe that the San Diego study has actually been peer reviewed.

The paper was only authored by Dr. Jack Ster, who was one of the two authors with Dr. Marline Burns, who, um, authored the San Diego study. But it brings into question, why was Dr. Burns not one of the authors of this peer review paper? And then on top of it, why would you need to write a paper to get peer reviewed and not just peer review the whole study.

You put all this work and effort into this whole study. If there’s no issues in the study, why would you not have the, the study peer reviewed? So I think those are major questions as well about the the San Diego study. Some additional things is the false positive rates were not published in the study.

So again, the only way to determine what the false positive rates are is to go in, look at the data and calculate it for yourself. And then they made ex made multiple statements to explain false positives. The first statement is they said that in several cases the officers were correct in identifying impairment.

Number one is they provide absolutely no science data or research to back up the statement. Number two, if we remember what I just talked about, that the authors are the ones that state the only objective criteria to measure or assess the accuracy of the standardized field. Sobriety test is BAC and measures of impairment are irrelevant.

Well, it appears that we only. Apply that rule. When we get the results that we want from the study, when we get false positives, now all of a sudden we throw that rule out the the window, and on top of that, if we’re going to err to the side that if an officer says a person’s impaired, they’re impaired, then there was no need for the study in the first place because we don’t need to study it.

We’ll just always say the officers are right. So obviously that’s an absolute. Insane statement that they’re making in that. And then number two is that they say case number 16 was a juvenile who was a 0.069, and that rendered the difference between their estimated BAC and measured BACS irrelevant and a zero tolerance jurisdiction.

That is, it was a correct arrest decision despite the BAC estimate. Here’s the deal. Yes, that was a correct arrest by the officers. The legal limit. This person was above the legal limit as a juvenile. But the test was still wrong. If the test is designed to discriminate, if a person is a 0.08 or above and it’s saying that this person was a 0.08 or above and they weren’t, then the test is wrong.

So again, as you see, they’re just making multiple, um, justifications of the false positives instead of just in a non-biased fashion reporting. Here’s the false positives based on our objective measurement. And then digging further into it and further studies to try and lower these false positives. But ultimately, NITSA has just sat on their laurels and not appeared to have any concern with what the false positive rates are of these tests whatsoever.

And obviously they don’t go out and ever tell anybody what the false positive rates are. And then the last thing that kind of comes out of the San Diego study, but it doesn’t officially come outta the San Diego study, but when an officer testifies to HGN and they say that it’s 88% accurate, the courts apply that across the board that this officer is just as accurate as any other officer.

Even when the officer is clearly not knowledgeable on the stand. We treat them all the same. So should that accuracy rate apply to all officers.

[00:38:36] Boating Under the Influence Study

Joshua Ott: This study, which was done for boating under the influence investigations when they were creating the seated battery, really illustrates that all officers are not even close to the same with their accuracy rate.

And what it found was it had, the officers had an average of almost 10 years experience administering the roadside standardized field sobriety test. So again, we’re not even talking about an um, inexperienced officers. We’re talking about only very experienced officers. How accurate were they? 20% of the officers involved in this study were less than 50% accurate.

With HGM. That is insane. And yet in court we’re treating all officers exactly the same every single time. And it’s not one of those where, you know, some officers were 88% accurate and some were 85% accurate. We are talking about less than a coin flip of accuracy for 20% of the officers in this study.

[00:39:35] Robustness of HGN Test

Joshua Ott: So now moving on to the robustness of the Horizontal Gaze Nystagmus Test.

This study was published in 2007. Again, it was funded by the National Highway Traffic

Safety Administration and authored by Dr. Meline Burns. So the purpose of this study was to address defense attorney arguments that when HGN is not administered correctly, it compromises the accuracy of the test. So what they did was they used, again, experienced officers, a total of seven officers were used in this study, same number as San Diego, and in a laboratory they dosed volunteers to different blood alcohol concentrations.

They then had the officers administer HGN to those volunteers. Now, there were three parts of the HGN test that they were looking at. To see if when an officer did it correctly versus incorrectly if and how it would affect the results. The first was the speed for lack of smooth pursuit, so they had one officer do it at the correct speed.

One officer did it too fast. They looked at the height of the stimulus, so one officer held at what they considered the standard of two inches above eye level, which is gonna be right about the center of a person’s forehead. They had one officer hold it above the standard elevation, which was considered four inches above eye level, right about the top of a person’s head, and then another officer held it below the standard at eye level, so zero inches.

And then the last thing they looked at was the distance of the stimulus from the person’s face. So correct was 12 to 15 inches, too close, was 10 inches, and too far away was 20 inches.

Again, as you can see, these are the, the things that they were testing. What were the results? Just looking at the times in which the test was administered correctly, the false positive rate was 67%. So two out of every three people below 8.08 had four more clues on HGM. Don’t worry, it gets even worse.

Below a 0.05, 65% of the people had still had four or more clues on HGM and where it gets very disturbing, and for some reason very weird, is that at the lowest Bacs people below a 0.03, 85% of them had four or more clues on HG. So the false positive rate, for some reason actually increases. At the lowest BACS versus in the range that’s just slightly below, um, the 0.05 range.

So for some reason it gets super high below a 0.03. Where do you find this,

Aaron Olson: Josh? In the paper.

Joshua Ott: What’d you say? Where do you

Aaron Olson: find that? Uh,

Joshua Ott: is it in the table that she provides? No, no. We’ll get into her, her crappy table in a second. Okay. Um, but it’s actually taking the, you have to take the, the actual, um, raw data and look at each individual person.

And so you’re gonna have to take the people that are a 0.029 and a and below and just take that total number of people, which you’re gonna get seven people who the test was administered to correctly. And then when you look at what their BAC is and how many clues they observed. Or when you look at how many clues are observed, that’s where you’ll get that.

There were six of them out of the seven that, um, had four more clues below a 0.03. Additionally, um, six outta six clues was observed at a BAC as low as 0.029, which is very consistent with the San Diego study, which had six outta six at a B, a C as low as 0.028. Now looking at the variance of stimulus positioning.

When the stimulus was held too high, it was a 91% false positive rate. So basically the test is almost completely worthless because it’s almost gonna always be positive when the stimulus is held too high, regardless of what the person’s BAC is when it’s held too low. 79% false positive rate. When it’s held too close, again, pretty much worthless at 92% false positive rate.

And when held too far away, 84% false positive rate. Number one is I think that this should make us say, why is HGN still treated as this great test when the false positive rates are through the roof, even when administered correctly? And then number two, why is the manual not very specific to officers of, hey, you have to position the stimulus correct, because if you do not, the false positive rate becomes extremely high.

Well. That’s because Dr. Burn’s ultimate statement in this study was the HGN is a robust procedure. Now, a couple things to point out with that. She does not say accurate, and she does not say reliable, but what she means by robust is ultimately, regardless of how you administer the test, it’s not going to compromise or affect the accuracy of the test.

How does Dr. Burns accomplish that after you just saw all the data? Well, we already talked about it multiple times. Four more clues indicates a B, a C of 0.08 or higher. That has been the standard since the 1998 San Diego study. And remember, Dr. Burns is the one that taught officers this standard, so there’s no chance that Dr.

Burns doesn’t understand the standard as of the 2025 edit to the SFST manual. This is still the same standard that applies today in this study. Dr. Burns changed the standard, and this is, um, copy and pasted directly from the study. I’ve highlighted the key areas. She stated that the criteria by which scores have been classified as correct, false, negative or false positive, and this is.

The, the biggest lie possible is that she says, as defined in the SFST curriculum, appear below, and that’s the box that she applies below. That box has never applied in any SFST curriculum. Dr. Burns, I can’t say that she came up with the curriculum, but she’s definitely. Intimately familiar with the curriculum and probably was helping create it if she didn’t create it on herself.

So she knows that this does not apply in the curriculum, and she knows that this is not the standard. But as you can see where the two arrows are. She says that four clues can indicate a, B, a, C of 0.03 or higher. So by doing this, it drastically lowered the number of false positives that she had to report occurring in this study, and that is how she was able to come out with all the statements that she does in this study.

That’s why we don’t have to talk about the 67% false positive rate. That’s why we don’t have to talk about the, the stimulus has to be positioned correctly because she fudged the ultimate data. And so in my opinion, what occurred in this study is that Dr. Burns took her opinions and then took the data and changed the standard to make it fit her opinions instead of.

Taking the data, applying the correct standard and forming her opinions on that. And so this brings serious questions into the credibility and integrity of Dr. Burns. And if that is an issue, all of a sudden we go back to these five studies out of six that were used to develop and validate the field sobriety test, and now we have an issue with the credibility and integrity of the author of all of those studies.

Now what happens with the robustness of the horizontal gaze nystagmus test when we talk about it in court, what’ll happen is they’ll talk about that. In 2018, the Drug Recognition Expert Tap Committee, the technical advisory panel, decided to retract this any mention of this study from all of their manuals.

So now if you mention this study, you’ll get attacked in court that you’re mentioning a study that has been retracted. Number one, it has only been retracted from the manuals. It has not been officially retracted. But number two is that it’s very self-serving of the DRE TAP committee to retract this study.

Because ultimately, in my opinion, this is a very, uh, this study is very exculpatory that. They are removing exculpatory evidence from being allowed. And what do we know from this study that we can verify? Number one is we have experienced officers. Number two, we know that the officers administered the test correctly.

Number three, we know what the person’s BAC was, and number four. We know how many clues the officer observed on that person. The numbers are what they are. This is the number of false positives that occurred, any which way you wanna look at it. And the biggest issue that I have is if you want to attack the study, then you have to attack the author of the study as well.

And they refuse to do that.

[00:48:47] 2023 Field Sobriety Test and Cannabis Study

Joshua Ott: So now the last study that we’re gonna talk about is the most recent, um, that I’m aware of is the 22, 20 20. 2023 field sobriety test and cannabis study. This was published in the Journal of the American Medical Association. To my knowledge, it’s a peer reviewed journal, very important distinction to the San Diego study that, again, was never peer reviewed.

And one of the questions you might have is, well, why are we talking about a cannabis study for DUI tests in general? And that’s because in this study there’s a placebo dosed group. So looking at the placebo dose group, we’re able to see how sober people perform on the field sobriety test. So what they did was, in this study, they used marijuana users who, before being allowed in the study, they had to be screened both physically and mentally.

And then on the day of the study they were given, um, a drug and alcohol test. Now after that, they had to perform on a driving simulator. And then after performing on a driving simulator, they were broken up into three different groups. One was a placebo dose group, and then the other two groups, one received a high dose of THC, and the other group received a low deal dose of THC.

We’re not gonna focus in on those two groups, just the placebo dose group. Then for the remainder of the day, they had to perform both the driving simulator and have multiple field sobriety tests administered to them throughout the day. The evaluators were certified drug recognition expert instructors.

So the top level of training that officers can have for DUI enforcement are the officers that they utilize in this study. These are the tests that were administered. So every one of the field sobriety tests, minus horizontal gaze nystagmus, was used for this study. The reason that horizontal gaze nystagmus was not used is that it’s not expected to be present for somebody who’s possibly under the influence of marijuana.

So it was removed from the study. Or not used in the study. And ultimately we have 63 placebo dosed individuals. Now, the one question we do have to ask ourselves is these are marijuana users. So even though they got placebo doses, were they high or were they having residual effects when they showed up?

Thankfully the study answers that question for us, and what it stated was that based on that initial driving simulator that occurred prior to any dosing, there was no evidence of these people having residual effects from prior marijuana usage. So all of the evidence of this study indicates that these people were sober when the field sobriety tests were administered to them.

So how did they do? Walk and turn 56% false positive rate. So when you are sober, it is statistically more accurate for an officer to flip a coin as to administering the walk and turn. This is very consistent with the 52% in the San Diego study. Next, we get to the one leg stand where it’s 37%. So one out of every three sober people was a false positive on this test as well.

Again, very consistent with the 41% false positive rate in the San Diego study. And then lastly, when combined, the false positive rate was 28%. So more than one out of every four sober people were false positives on both the walk and turn and when they stand. But I think ultimately, yes, this gives us data to prove it, but majority of people that are thinking with common sense already know that sober people are going to have difficulty on the walk and turn, and when they stand, this just gives us data to support that.

Now what’s kind of funny in this study is they, they make this statement of that they were kind of surprised that, you know, with officers knowing that there were gonna be placebos, that basically every time the person was ruled FST impaired on the field sobriety test, the officers believed it was because they were under the influence of cannabis.

They were surprised by that. And I just think it’s funny because if you go through the training, especially ARIDE and DRE, that’s basically what they’re hammering home is that when these tests tell you to take somebody to jail, the test is right because they indicate impairment when obviously we know that they don’t.

And they’re surprised when officers arrest people because they do poorly on the field sobriety test. And again, as we can see, normal sober person, sober people are going to have issues on these tests.

[00:53:17] Final Thoughts on Field Sobriety Tests

Joshua Ott: So my final thoughts are, number one, the SSTs have not been validated indicated impairment, but that testimony is provided throughout the United States daily and every time as an expert.

When you get on the stand and you talk about the field sobriety test, this is a mistake that cannot be made. You cannot at all make that slip up of saying impairment in regards to these tests. Do these tests indicate that there’s possible impairment? Yes, but they do not actually indicate impairment. And you know, every time I teach the standardized field sobriety test to course to attorneys, I’m making sure to hammer that point home because if judges are hearing it, regardless of who they’re hearing it from, it’s strengthening.

That lie that’s been told for a long time and it again, it’s a huge uphill battle that we have to fight and we might never be successful in it because it’s been told for so long, but we can’t have slip-ups and have anyone saying that these tests indicate impairment because again, they clearly do not.

The tests have very significant false positive rates, and the officers, prosecutors, and judges are not aware of them. And again, this is a huge problem that so much reliance is put on these tests. And every time I go to court and I’m testifying to the false positives, I am in a knockout, dragged out fight with the prosecutor.

And a lot of times the judges aren’t even believing it because this is contrary to what they’ve been trained for so long. And then lastly is that the JAMA study provides a lot of insight into how a sober person performs on the walk and turn in one leg stand, but ultimately, many elements. Still remain unaddressed age.

We all can probably agree that 40 year olds, 50 year olds, and 60 year olds cannot balance and do things with their balance as well as what they could when they were in their twenties. But we treat age 21-year-old the exact same way that we treat a 64-year-old on these tests. Additionally, just when I teach these classes and I’m demonstrating the walk and turn, the amount of difficulty I have now in my forties maintaining the instructional position versus when I was an officer in my twenties and thirties and I could just stand there all day is very eye-opening.

Additionally, we have no idea how weather actually impacts the test. What about surface conditions? Footwear, A person wearing tennis shoes versus a person wearing flip flops or heels that they choose not to take off or barefoot. All of those things could possibly impact the test and likely impact the test.

And yet we treat people exactly the same regardless. And then lastly is injuries. Yes. The original research states that people would lag back or enter ear problems, would have difficulty on the test, but the argument that’s always made to that is, well, they didn’t actually research it. Well then let’s research it.

Let’s find out what impact all of these different things have on the test because. Yes, we have the JAMA study, but those people were screened ahead of time. Those are, you know, the, the best of best of society physically and mentally. That isn’t a lot of times what officers are encountering on the side of the road.

So what happens to the false positive rates when we’re dealing with people with other conditions or in other surface or weather elements? Any questions?

Minutes after I published a LinkedIn post criticizing the Minnesota Bureau of Criminal Apprehension for failing to respond to my government data practices request, I received an email from the BCA.

They claimed they had fulfilled my data practices request.

I had been waiting over two months for the information about their recent dry gas reference material debacle, a quality control failure that invalidated dozens of breath alcohol test results.

The timing was remarkable.

Two months of silence, then a response within minutes of public criticism.

But as I reviewed what they sent, the real story became clear: this wasn’t compliance. It was the appearance of compliance.

What I Asked For

My data practices request was straightforward. I asked for seven specific data fields from breath alcohol tests performed on the DataMaster DMT during the period when the dry gas reference material problem occurred:

• Audit-ID

• Date/time

• BrAC1 (first sample)

• BrAC2 (second sample)

• Control Target

• Control Reading

• Control Lot Number

These fields are all maintained in the BCA’s records system. They’re all essential for conducting a meaningful review of the quality control data.

The Audit-ID uniquely identifies each test. The Control Lot Number identifies which specific batch of reference material was used. Without these fields, it’s impossible to properly analyze what happened during the dry gas cylinder failure.

What They Sent

The BCA provided five of the seven fields. They omitted the Audit-ID and the Control Lot Number.

Think about what this means.

I can’t see which lot of reference material was in use. My request has been rendered essentially useless.

A Pattern of Resistance

This isn’t an isolated incident. It’s part of a broader pattern of how the BCA responds to external oversight.

External review uncovered an error that had persisted for nearly a year.

The same pattern appeared in our research documenting systematic problems in forensic laboratories: external oversight consistently uncovers errors that internal systems miss.

Now, when someone requests the data needed to conduct that external oversight, the response is strategic incompleteness.

Provide enough to claim compliance, but withhold the key fields that would enable meaningful analysis.

Force the requester to file disputes, engage in additional correspondence, and spend more time fighting for access to public data.

It’s institutional resistance dressed up as a bureaucratic process.

The Integrity Problem

The BCA publishes its organizational values on its website. Two of those values are particularly relevant here:

“Integrity: Integrity is the cornerstone of public trust. This organization strives to always do the right thing.”

“Excellence: We value excellence in our people and our work to continually provide the best service to our partners, the Minnesota criminal justice community, and the citizens of this state.”

Providing an incomplete response to a data practices request while claiming to have fulfilled it doesn’t reflect integrity. It doesn’t reflect a commitment to “always do the right thing.”

It reflects an organization more interested in managing its image than serving the public interest.

Excellence doesn’t mean finding creative ways to avoid transparency. It means recognizing that transparency strengthens forensic science and that independent oversight is essential to maintaining public trust.

What Other States Do

The contrast with other jurisdictions is stark.

Iowa, Alaska, Washington, and Massachusetts routinely publish their breath testing quality control data online. Anyone can access it. Anyone can review it. These laboratories recognize that transparency isn’t a threat to their work. It’s a validation of it.

When your quality control systems are working, you want people to see the data.

When you’re confident in your procedures, you welcome external review. When you’re committed to scientific integrity, you embrace transparency as an opportunity to demonstrate that commitment.

Minnesota takes the opposite approach.

The BCA treats public data as something to be protected, managed, and strategically released in incomplete forms that minimize scrutiny while maintaining the appearance of compliance.

Moving Forward

I’ll keep pushing for the complete data. I’ll continue documenting these patterns of resistance. And I’ll keep making the case for why forensic laboratories need to embrace transparency rather than fight it at every turn.

Minnesota can do better.

The BCA can do better.

Other states have shown that it’s possible to operate forensic laboratories with genuine transparency and public accountability.

The question is whether Minnesota is willing to follow their lead, or whether the state will continue playing games of incomplete compliance while pretending to value integrity and excellence.

My latest paper, Compliance by code: The need for automated protocols in breath alcohol testing – case reports, just published in Forensic Science International: Synergy, documents something I’ve been observing: breath test operators routinely ignore instrument warnings and violate established protocols.

Not because they’re malicious, but because the current system gives officers too much discretion in how testing is conducted.

The Cases That Shouldn’t Have Happened

Let me tell you about two cases from 2024 that illustrate the problem.

Case 1: The Interference Flag

A subject was being tested on a DataMaster DMT. The instrument produced an “Interference” message—not once, but twice. This message means the breath sample contained compounds other than ethyl alcohol.

The Minnesota DMT Operator Training Manual is explicit about what to do next:

“Obtain a warrant and collect blood or urine for analysis.”

Instead, the operator moved to a different instrument and obtained a numerical alcohol result.

The absence of an interference message on the second instrument doesn’t prove that the interfering substance disappeared.

It only means the interfering compound fell below that particular instrument’s detection threshold.

The same contaminant could still be present, still contributing to an artificially elevated result.

Case 2: The Observation Period That Wasn’t

The second case involved a subject whose breath-testing sequence produced four “Invalid” status messages indicating mouth alcohol contamination.

Each one came with an expirogram showing a negative slope, which is a signature of mouth alcohol contamination.

During testing, the subject literally said, “Sorry for burping.”

The officer acknowledged this might indicate mouth alcohol contamination, telling the subject,

“I think the first one possibly could have been detected with mouth alcohol, so you might not even be that high.”

Then, continued testing without restarting the observation period.

To make matters worse, the subject was allowed to use the restroom unobserved during what should have been a continuous observation period.

On the fifth attempt, a numerical result was finally obtained. But because protocols were not followed, the validity of the final test was questionable.

Why This Matters

When protocols meant to prevent mouth alcohol contamination or interfering substances from adding to a breath alcohol test are violated, the measurement is no longer valid.

That’s why protocols exist. The protocols are designed to uphold quality assurance.

The Retraining Fallacy

The typical response to cases like these is predictable: identify the operator, provide additional training, document the corrective action, move on.

But this approach misses the point.

Retraining doesn’t address the fundamental problem: human decision-making in high-stakes moments where the correct choice might be inconvenient.

The Automation Solution

Modern laboratories have largely solved the problem through automation.

In toxicology labs analyzing blood samples, instruments follow programmed sequences that don’t change based on the technician's preferences.

Quality control checks are mandatory, not optional.

Why should breath testing be different?

Automated protocols in breath testing would:

• Prevent instrument switching after interference flags through networked communication between instruments

• Enforce observation periods by locking out testing until the required time has elapsed

Automation simply removes discretion from the areas where discretion creates vulnerability.

The Objection I Hear

“But this will make testing take longer.”

Yes. Sometimes it will.

And that’s exactly the point. When an instrument produces an interference warning, the scientifically correct response takes more time than ignoring it.

When mouth alcohol is detected, restarting the observation period takes more time than continuing with another test.

We need to decide whether we prioritize speed or scientific validity. We can’t have both in every case.

Judicial Precedent

The North Dakota Supreme Court recently decided Gackle v. North Dakota Department of Transportation (2025), ruling that failure to observe the full required observation period before retesting constituted a deviation from approved methods and rendered the results inadmissible.

This case signals that courts are starting to take protocol compliance seriously. But we shouldn’t need judicial intervention to enforce basic quality assurance practices.

The technology to automate these safeguards exists right now.

The question is whether breath testing programs value consistency and reliability enough to implement it.

The Bigger Picture

The lesson from other forensic disciplines is clear: standardization and automation improve reliability.

My article documents just two cases, but they represent a systematic problem.

Until we acknowledge that breath-test operator discretion is a bug, not a feature, we’ll continue to see protocol violations treated as isolated incidents rather than symptoms of a flawed system design.

The evidence is clear. The solution is available. The only question is whether breath testing programs will act on it.

You can read the full article in Forensic Science International: Synergy.

I’m happy to announce the publication of my latest article, “Extended absorption, implications: Rethinking alcohol pharmacokinetics in forensic calculations,” in the Medico-Legal Journal today.

This paper addresses a critical gap between what the science tells us about alcohol absorption and what actually happens in forensic casework.

The Two-Hour Rule That Isn’t Really a Rule

Here’s a scenario that plays out in courtrooms across the country: A driver has dinner with drinks, crashes two hours later, and gets blood drawn an hour after that.

A forensic toxicologist performs a retrograde extrapolation, working backward to estimate what the driver’s blood alcohol concentration was at the time of the crash.

The standard assumption? Alcohol absorption was complete within two hours of the last drink.

But what if that assumption is wrong?

Through a data practice request, I obtained and analyzed 36 retrograde extrapolation reports from the Minnesota Bureau of Criminal Apprehension’s toxicology section from 2023 to 2024.

The findings were striking in their uniformity: All 36 reports assumed absorption was complete within two hours.

None adjusted for food consumption, medications, medical conditions, or trauma. Only one even mentioned that blood loss from trauma could delay absorption.

What the Science Actually Shows

The scientific literature paints a very different picture from this one-size-fits-all approach:

Individual Variation is Massive
Dubowski’s seminal 1985 review documented a 14-fold variation in time to peak blood alcohol concentration among healthy individuals, ranging from 12 minutes to 3 hours. One subject in his data took approximately 3.25 hours to reach peak concentration.

Food Changes Everything
Jones and Neri’s 1991 study showed that consuming alcohol with a large meal dramatically alters absorption patterns. One subject didn’t reach peak concentration until 230 minutes, nearly 4 hours, after finishing drinking. The researchers specifically cautioned against retrograde extrapolation without considering these individual variations.

Medical Conditions Matter
People with GERD showed average peak BAC times of 3.5 hours (range: 2-5 hours) compared to 2.5 hours in healthy controls, according to Booker and Renfroe’s 2015 study. The pathophysiology of GERD delays gastric emptying, keeping alcohol in the stomach longer before it reaches the small intestine, where most absorption occurs.

The GLP-1 Factor
Here’s something forensic toxicologists need to start thinking about now: millions of Americans are taking GLP-1 receptor agonists like Ozempic and Wegovy.

These medications work partly by deliberately slowing gastric emptying. It’s gastroparesis by design.

If they’re doing what they’re supposed to do therapeutically, they’re almost certainly affecting alcohol absorption kinetics. An emerging study has already found that these medications delay the rise in breath alcohol concentrations compared to controls.

Why This Matters in Court

When an analyst performs retrograde extrapolation while someone is still in the absorptive phase, the calculation will overestimate their blood alcohol concentration, potentially by a significant margin.

This isn’t a minor technical quibble. It’s the difference between a BAC estimate that reflects reality and one that doesn’t.

Current professional guidance acknowledges that “studies support that it can take up to 2 hours” to reach post-absorptive status, but doesn’t provide methodology for evaluating cases where absorption extends beyond that timeframe.

The ANSI/ASB standard for alcohol calculations doesn’t require systematic assessment of case-specific variables that could substantially prolong absorption.

What Needs to Change

Forensic toxicologists should:

1. Evaluate each case individually for factors that may extend absorption beyond two hours. They must look at detailed consumption history, food intake, medications, medical conditions, smoking, and trauma.

2. Consider longer absorption windows when uncertainty exists, rather than defaulting to the two-hour assumption.

3. Document and justify the factors considered in determining post-absorptive status.

4. Explicitly state limitations rather than presenting calculations as having more precision than the science supports.

The Bottom Line

The human body doesn’t operate according to arbitrary time limits.

Evidence shows alcohol absorption can extend 2-5 hours beyond the last drink, depending on circumstances.

Dubowski himself expressed skepticism about retrograde extrapolation precisely because of this variability, stating that “no forensically valid forward or backward extrapolation of blood or breath alcohol concentrations is ordinarily possible in a given subject and occasion solely on the basis of time and individual analysis results.”

Individual physiological variation isn’t an exception we need to account for occasionally—it’s the norm. Our forensic practice needs to reflect that reality.

The article is now available in the Medico-Legal Journal: https://doi.org/10.1177/00258172251382701

On November 13, 2025, the Iowa Court of Appeals issued its opinion in State v. Withers. Buried in the dissenting section of the case was something I did not expect to see: a direct citation to my article, coauthored with Chuck Ramsay, titled "Errors in Toxicology Testing and the Need for Full Discovery," published in Forensic Science International: Synergy.

Read the full court decision below:

240661 State V Withers A612267f83dab

248KB ∙ PDF file

Download

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For someone who works to improve the reliability and transparency of forensic testing, seeing my research used in a judicial opinion was encouraging. More importantly, it shed light on a growing conversation within the courts about how forensic evidence is handled.

The Case: Late Forensic Disclosure and Fairness

The central issue in the dissent was a sixty-three-page digital forensics report that the prosecution disclosed only eight days before trial. The defense attorney told the judge he did not understand the report, did not have time to consult an expert, and could not properly evaluate the data's accuracy or reliability.

The majority decided the late disclosure was acceptable and affirmed the conviction.

The dissent argued that this was a clear injustice. You cannot meaningfully challenge forensic evidence on the eve of trial without time, expertise, and full discovery.

To underscore this point, the dissenting judge wrote:

“I worry that treating an untimely expert witness disclosure like any other witness disclosure perpetuates my concern about how we treat forensic evidence in the courtroom.”

This simple sentence captures a larger problem in the criminal justice system.

Forensic evidence is often treated as if it is infallible, even though entire scientific bodies of research show that errors, limitations, and methodological problems are far more common than many assume.

That is exactly where my article fits into the discussion.

Why the Court Cited My Research

The dissent referenced our work while explaining why late forensic disclosures are especially dangerous. My paper makes several points that were directly relevant to the concerns raised in this case.

1. Forensic evidence is not self-validating

Instrumentation, data interpretation, and laboratory processes are all subject to error. A late disclosure does not allow the defense enough time to identify or challenge mistakes.

2. Full discovery is essential for meaningful review

Experts need the underlying data, not just a summary. Without sufficient time to examine the raw information, the defense cannot verify accuracy or expose analytical issues.

3. Courts often treat forensic results as more reliable than they are

The dissent cited my article, along with work by leading scholars such as Brandon Garrett, Peter Neufeld, and Jennifer Mnookin, to argue that forensic evidence must be handled carefully and critically.

• Invalid Forensic Science Testimony and Wrongful Convictions

• The Courts, the NAS, and the Future of Forensic Science

Why This Citation Matters

Seeing courts cite forensic science scholarship in real cases is a positive sign that conversations about transparency, discovery, and scientific rigor are reaching the places where they matter most.

I plan to continue advocating for full discovery, independent review, and scientifically grounded forensic practice.

My latest editorial, Truth, Power, and the Crisis of Forensic Independence, has just been published in Forensic Science International: Synergy. The article examines the structural forces that shape how forensic evidence is interpreted, presented, and, at times, suppressed.

I focus on the sociological, anthropological, and historical patterns that explain why institutions repeatedly expel those who threaten their authority.

The Core Problem

Forensic laboratories claim scientific independence while operating under the administrative and financial control of law enforcement hierarchies. This fundamental structural conflict undermines the credibility of forensic science itself.

When scientists challenge prosecutorial narratives or expose systemic problems, they frequently face professional retaliation, forced resignations, or career marginalization. The editorial argues these aren’t isolated incidents but symptoms of a deeper governance failure.

Historical Parallels

The piece draws parallels between ancient mechanisms of enforcing orthodoxy and modern institutional responses to dissent. I draw on historical parallels of dissenters who resisted the pull of power to modern-day examples of lab whistleblowers.

The mechanisms of punishment have changed throughout history, but the purpose remains the same: to preserve institutional legitimacy by marginalizing the dissenter.

Documented Cases of Retaliation

The editorial examines several cases:

Gregory Ohlson (Arizona DPS): Forced into early retirement after testifying that laboratories should disclose full batch data, despite federal acknowledgment that his speech was constitutionally protected.

Darcy Richardson (Vermont): Reported that technicians were artificially spiking control samples. Her warnings were ignored, and courts later dismissed cases on the very grounds she had identified.

Bethany Pridgen (Wilmington Crime Lab): After testifying about missing drug evidence and laboratory mismanagement, authorities transferred the entire lab out of city control to eliminate her position.

Itiel Dror (Cognitive Psychologist): His methodologically sound research on cognitive bias in forensic pathology provoked intense backlash; not because his research was flawed, but because its implications were uncomfortable.

The Scapegoat Mechanism

These cases reveal how institutions protect their authority not by confronting error, but by expelling those who reveal it.

Drawing on René Girard’s theory of scapegoating, I analyze how communities preserve unity by expelling the individual who exposes the internal contradictions of their shared myths.

In forensic science, the myth is that state laboratories are impartial guardians of truth. When someone undermines that belief, the institution responds with expulsion rather than reflection.

The Path Forward

More than fifteen years after the National Academy of Sciences warned that forensic laboratories cannot claim objectivity while operating under law enforcement control, the institutional framework remains largely unchanged.

We need change. I’m calling for:

• Genuine scientific independence: Forensic laboratories governed by scientists, not law enforcement hierarchies.

• Mandatory full disclosure: Complete transparency in methods, data, and results available in online discovery portals.

• External peer review: Independent oversight from external experts outside of the system.

• Whistleblower protections: Protected avenues for challenging entrenched narratives without fear of reprisal.

Science must remain self-correcting and free from the gravitational pull of power.

When science can question authority without penalty, it fulfills its role as an instrument of truth. The integrity of forensic practice depends upon preserving that freedom.

Building on Previous Work

This piece extends the analysis Chuck Ramsay and I began in Errors in Toxicology Testing and the Need for Full Discovery, which documented systematic problems including calibration failures, discovery violations, and whistleblower retaliation.

Read the Full Article

The editorial is published as open access:

“Truth, Power, and the Crisis of Forensic Independence”
Forensic Science International: Synergy 11 (2025) 100647
https://www.sciencedirect.com/science/article/pii/S2589871X25000762

If you’re interested in the intersection of forensic science, law, and justice, take a listen.

Our article, Errors in toxicology testing and the need for full discovery, reviews the vulnerabilities inherent in toxicology, despite its foundation in analytical chemistry.

The podcast dives into the many ways things can and have gone wrong.

The podcast highlights key categories of toxicology errors we documented from across multiple jurisdictions:

• Traceability and Calibration Failures: Errors stemming from incorrectly produced reference materials or using improper formulas.

• Discovery Violations: The widespread problem of laboratories deliberately withholding exculpatory evidence, such as failed calibration records, from the defense.

• Source Code Defects: Discussing how proprietary software can contain programming flaws, sometimes with more lenient tolerance limits than required by law, silently compromising the validity of thousands of tests.

• Interfering Substances: Cases where the lab method failed to distinguish between compounds, like propionic acid being mistaken for ethylene glycol (antifreeze), or the more recent issue of distinguishing illegal delta-9-THC from other THC isomers.

• Fraud and Misconduct: Covering deliberate misconduct, such as the manipulation and falsification of certification records and test data, as seen in cases like the Randox scandal in the UK.

Transparency is the Path Forward

The core of our paper is a call for systemic reform to enhance both scientific integrity and the pursuit of justice. As discussed on the podcast, key reforms include:

• Transparency through Online Discovery Portals: Providing online access to all validation studies, maintenance records, and quality assurance reports.

• Mandatory Retention of Digital Data: Preserving all digital data, including expirograms for breath tests, since the original samples cannot be retested.

• Protection for Whistleblowers: Establishing legal protections for forensic scientists who report analytical problems, as the threat of retaliation creates a “chilling effect” that perpetuates problems.

The path forward is clear: transparency, accountability, and rigorous, independent oversight. Whether it’s mandating the disclosure of digital expirograms for breath tests, or establishing protections for scientists who speak up, these reforms are non-negotiable.

Many thanks to The Tox Lab for bringing this critical discussion to light.

When most people think of DNA evidence, they think of certainty. They think of “slam-dunk” proof that can put the right person behind bars or clear the innocent.

But what happens when the science itself goes off the rails?

In this week’s episode, I talk with Tiffany Roy, a forensic DNA expert, consultant, and founder of ForensicAid. Tiffany has spent her career examining the hidden flaws in DNA analysis and exposing systemic problems in how some public crime labs handle evidence.

Her recent critiques of the Minnesota Bureau of Criminal Apprehension (BCA), including their mishandling of complex DNA mixtures, have sent ripples through the forensic community.

Tiffany discusses landmark cases such as Minnesota v. Porter and Minnesota v. Bell, in which judges ruled that the BCA’s DNA evidence failed to meet scientific standards.

She also filed formal complaints with both the BCA and their accreditor, the ANSI National Accreditation Board (ANAB), and later with ANAB itself for failing to investigate her concerns in a timely manner.

Her findings reveal how flawed science can persist in the courtroom and how accountability, even in something as technical as DNA, often depends on individual experts speaking up.

Clips

Highlights

• Poor understanding of validation and mixture interpretation has plagued the BCA DNA lab.

• Significance of Minnesota v. Porter and Minnesota v. Bell, where judges excluded BCA DNA evidence for being scientifically unsound.

• Roy discusses her 2021 complaints to the BCA and ANAB, including how the accreditor took nine months to notify the lab and later admitted her concerns were valid.

• Outlines how the BCA’s leadership treats written procedures as “guidance,” violating accreditation norms.

• Explains why forensic leaders resist criticism, citing a culture of self-protection and the Dunning-Kruger effect.

• Calls for forensic commissions with real power and legislated depositions to promote transparency and accountability.

Links

• Criminalistics: An Introduction to Forensic Science, 13th edition by Tiffany Roy

• Reducing the impact of cognitive bias in decision making: Practical actions for forensic science practitioners

• A practical tool for information management in forensic decisions: Using Linear Sequential Unmasking-Expanded (LSU-E) in casework

• Forensic Science, An Introduction, 4th edition by Saferstein | Roy

Related Podcasts

• Forensic Science Under the Microscope: A Look at Cognitive Bias

• When Science Meets Justice: Fred Whitehurst’s Fight Against FBI Lab Misconduct

• The Accuracy of Standardized Field Sobriety Testing (SFST) with Dr. Greg Kane

• Challenging the Validity of SFSTs and Drug Recognition Testing with David Rosenbloom

• Shattering Accreditation Illusions: ISO 17025 Myths and Realities

Automated Transcript (not checked for errors)

[00:00:00] Introduction and Guest Introduction

Aaron Olson: Hi everyone, and welcome back to the podcast. Today I’m talking with Tiffany Roy. Who is a forensic DNA expert and founder of Forensic Aid, where she helps attorneys and labs across the US and internationally understand the challenges of forensic evidence. Today we’re diving into what happens when DNA analysis goes wrong, how labs fall short, and what needs to change in the way of forensic science and how it’s used in the courtrooms.

Tiffany, thanks so much for coming on the podcast.

Tiffany Roy: Thank you for having me.

[00:00:28] Tiffany’s Background in Forensic DNA

Aaron Olson: So to start off with, tell me a little bit about yourself, uh, your background and how you got into forensic DNA analysis.

Tiffany Roy: I started my career in forensics at the Massachusetts State Police Crime Lab in their DNA unit. And, um, while I was there, I sort of realized that the culture within the laboratory, um, and, and just the.

The politics involved in, in working in a crime lab were just not for me. So about seven months after I began working there, I enrolled in law school and I started taking classes to become a lawyer at night. And I did that throughout my entire tenure at Massachusetts State Police. I graduated from law school in 2010 and took the bar.

And in that time, um. I took a job at a private laboratory in Deerfield Beach, Florida that tested evidence mainly for government crime labs and police departments called DNA Labs International. Um, so I, so I tested evidence, um, at both Massachusetts and DNA Labs International, and I wrote reports about my findings and I testified to those findings in court and.

Sometime in 2013, I left DNA Labs International at the end of that year and began consulting. So I, I taught at a few local colleges. There are some colleges online, um, classes in the area of forensics and law. And then I began to review cases for criminal defense attorneys mainly, and, um, examined.

Evidence from a wide swath of public laboratories, public and private laboratories from around the us and began to realize that not everybody is doing things, uh, the same or not. Everybody’s doing things well and not everyone’s doing things correctly. So that’s how I came to be in the position I am now.

Um, and, and that’s primarily the work that I do.

Aaron Olson: So tell me about more about that. So you found out that not everyone was doing things correctly.

[00:02:41] Issues in Forensic DNA Analysis

Aaron Olson: Uh, lately you’ve been posting things on LinkedIn and, and specifically you said that the Minnesota BCA DNA, uh, they’re not doing things, uh, as you would expect.

Tell me more about what’s going on there. So,

Tiffany Roy: I’ve worked with some really great, um, defense attorneys in Minnesota, and I first became involved in doing. Case work. They’re reviewing cases from that laboratory sometime around 2020. Um, I submitted my first complaint regarding the laboratory processes in 2021.

So that went to the Minnesota BCA QA department first, and then, um, they had their. They have to perform their investigation. Um, and then if I don’t find their investigation satisfactory, then I can escalate it up to to A NAB, and that’s what I did.

[00:03:35] Problems at Minnesota BCA Lab

Tiffany Roy: So essentially the problems in Minnesota at their crime lab, um, deal with complex mixtures, which is not a problem isolated to this particular laboratory, but it is particularly egregious at this laboratory.

What. The problem entails is that when we’re interpreting complex data from a DNA profile where there are mixtures of more than two people, um, and varying amounts of DNA, it’s very, very difficult to identify which parts and pieces in the DNA profile could come from a single contributor. And there are many laboratories in the United States that have had problems with this and that have been doing things not correct.

We as a field have implemented some tools that were designed to try to standardize these processes. But essentially the BCA lab had a problem always with not understanding the concept of validation and why validation is important, and why validation sets the perimeters for your standard operating procedures and how you operate within the confines of your validation.

So they had this problem when. They were manually interpreting mixed DNA profiles, complex mixtures. And, um, we’ve implemented some computer programs that have been designed to try to make some of the assessments, um, in a more uniform way. And BCA continues to struggle and, and. Operate outside of their own standard operating procedures and outside of their own validation.

So these problems have persisted there for a significant amount of time. There have been many independent DNA experts that have come through and reviewed cases from the Minnesota BCA that have excellent credentials and who are very experienced and proficient outside of myself that have identified similar problems, but the laboratories cannot be convinced that.

It needs to address some of the interpretation issues that it has with its mixture procedures. So I’m not the first to address this laboratory, and I’m certain I won’t be the last. And there have been a number of excellent lawyers and excellent forensic DNA analysts who have tried to help the laboratory to get, um, in line with standard and best practice.

And we’ve been unsuccessful to this point in doing that. Through the scientific process.

[00:06:02] Legal and Accreditation Challenges

Tiffany Roy: So laboratory quality assurance systems and accreditation lab, forensic laboratory accreditation. And at this point, we’re having success, more success now in the court system and having the evidence excluded than we are.

Ha, you know, effectuating the. The oversight, the forensic oversight that we have to step in and make necessary changes. So that’s, that’s how we came to be at the point that we’re at.

Aaron Olson: And you mentioned that you had recently heard some more news from A NAB. Can you share more about what happened or what’s going on there?

Tiffany Roy: So, uh, I have several cases that are pending, um, litigation on. For exclusion from court proceedings, and I’m aware of a number of cases that have just been excluded and the judge’s rulings are scathing. Uh, essentially they’re the findings and the, the main cases. Um. That have identified these problems.

[00:07:04] Case Studies and Court Rulings

Tiffany Roy: One is Minnesota v Porter, and that was heard before. Uh, judge Pam King, who is very active in the forensic community, knows what she’s talking about, understands the concepts of validation. Um, and the expert in that case was Cynthia Kale, who is a close colleague of mine. I rely on her for, uh, like as a sounding board.

And consultation. Um, and the lawyer involved with that, the defense attorney was, um, JD Schmidt, who was also exceptionally proficient in identifying problems and understanding forensic DNA. So that was really the first case to, um. To have the evidence successfully excluded for failure to adhere to the validations and their own standard operating procedures and interpretation of the DNA profiles in that case.

And there was a second case, um, that where the evidence was just excluded on very similar grounds, and this also involves Cynthia Kale, but this was, um, defense attorney involved in this was Sarah Prentice Mott, and this case is Minnesota VI Bell. So these cases all have very similar issues. I have several cases with, um, with attorney Mott Prentice Mott, and I just received another case that’s also very egregious.

So the more cases that stream past me, um, and the, the, the longer I see these problems persist, I. It triggers me to wanna reach out again to the accrediting body and ask them to become involved. It’s obvious that the BT A is having problems in some other areas of forensic science, but I approached the laboratory and a and a B about their failure to do these things that are the subject of these most recent court rulings, you know, four, four years ago.

And. I submitted a formal written complaint to both the laboratory and A NAB, um, the laboratory. It took them, I think, more than a year to investigate and formally respond, which in order to escalate this up to a, a b to the crediting body, um, the laboratory, they require you to submit the complaint directly to the laboratory quality management system to allow the lab the time that.

It needs to investigate and see if they can deal with the problem on their own. If they can identify it and, and implement corrected measures, um, that, that the accrediting body finds sufficient, then there’s no need to escalate it up to the accrediting body. But that’s not what happened. I submitted my complaint to the BCA.

They did their investigation and told me that they felt my concerns were without merit, and then I escalated that up to. In 2021, um, A NAB. I had cases continuing to come through the BCA, and I was working on one particular case with attorney JD Schmidt, and I mentioned to him that I had written this complaint.

What is the status of this complaint? Let’s do some legal discovery to find out what investigation is taking place, what is happening at A and a B? What documentation can we get from them about what my concerns are and how those are being investigated? And. JD Schmidt made a public records request to the laboratory for any communication from A NAB regarding the substance of my complaint that I had lodged with them, which they had accepted, acknowledged that I had all the proper paperwork, and, um, essentially promised to investigate timely, and A NAB sat on that complaint and never even notified the laboratory of its existence for nine months.

So when he reached out for the communication between the accrediting body in the lab, there was none. And, um, that triggered me to file a complaint against the accrediting body itself for failure to investigate timely. So all of that time, a year plus of bad cases while they, while the laboratory tried to identify my concerns to them.

And then nine months of failed investigation for A and a B, we’re talking about two years. These concerns were expressed and not addressed because the forensic accreditation process requires these initial steps to take place. And because they failed to even attempt even notify the laboratory that I had concerns that I escalated to them.

Um. And so I filed a complaint against the accrediting body and they found, so they had to investigate themselves now at this point for failure to investigate, and they found that my concerns had merit. So A and a B themselves admitted that what took place in this particular instance was unsatisfactory and problematic.

I mean, if we submitted, if a victim went into a police station and reported a sexual assault and the police department took nine months to investigate it, we would be outraged by that. That would be professional negligence. And I feel like that was professional negligence in the instance of my complaint about the BCA.

And A NAB agreed with me, but they never told me what remedial measures would be taken to ensure this didn’t happen again in the future. They never provided to me any information about, um, what their investigation into my concerns about them entailed my concerns about the BCA entailed. Um, I did receive two closures of.

Complaints, one page closures, um, for findings, saying that they didn’t believe that my concerns about the VCA had any merit. And I got an, and it was another closure on the same day, um, which looked to me like they were just trying to get rid of me and clear the docket, um, without really looking into any of the concerns I had expressed.

So when I received another bad case last week, I. Resubmitted all this paperwork to them again and essentially stated, you know, now we have this Porter decision and now we have this bell decision where two different judges in Minnesota and. Two different lawyers on different cases identified the same issues that I expressed to ‘em in 2021.

The problems are still persisting, even though they found that my concerns didn’t have merit. These judges have now found that my concerns have merit because these, this is still happening at B-C-A-D-N-A lab. And I asked them to go in there with an expert, a qualified expert, and I mentioned two people’s names, um, and examine at least the two cases that have been excluded from use in court and see if the problems of.

Failure to adhere to your validation and failure of you to adhere to your SOPs, which flow from your validation. And they sent me back communication today that I need to submit a new quality assurance complaint to the Minnesota BCA before A and a B will accept my most recent complaint. And so the process begins again.

And bad cases flow into our court system for judges that are not as sophisticated as the judges in the two cases I mentioned and. I read and reread the requirements from A and a B, and I have fulfilled the requirements as they’re written. There is no re requirement that I submit a new complaint to reiterate my same concerns, and I’m going to address that with them.

But I know that I. I’m not gonna waste any time before I submit complaints to BCA to get that process started for them to investigate what happened in Porter and what happened in Bell. Because if these judges can identify that there’s a problem through testimony and legal presentation by lay lawyers.

Then this laboratory should absolutely be able to identify the problems identified by these judges and figure out whether this is systemic, because I know it’s systemic. Um, and, and aside from this is that I, I feel that. The BCA. Once these cases were excluded by judges based on scientific basis, the laboratory themselves should have opened a quality investigation into what happened and why the judges must have felt the way they felt.

Um, you know, they had clear violations, clear instances of them not following their procedures, which they de describe in testimony as guidance. Which Pam King rejected. Um, you know, these rulings and these transcripts contain information that the judges relied on to say you’re not following your own rules that you set for yourself, and that should be giant accreditation concern.

And it should be a giant laboratory concern. You know, these aren’t just guidelines. These are hard and fast rules, and if you’re gonna depart from them, you better have a good damn reason why. And they just don’t, they don’t feel like they need to do that. And the, the individual who runs the laboratory, her name is Marilyn Horn.

She cannot be convinced that you know, that these people need to do this in a consistent way. That they need to adhere to their standard operating procedures very closely and that their standard operating procedures flow from the data in their validation. So if you have a case where there’s a profile that doesn’t look anything like the profiles you tested in your validation, you shouldn’t be interpreting it.

Um, and she doesn’t understand that as a fundamental concept that the validation is vitally important and you have to operate within the confines of your validation. And so that’s a giant problem where the problems roll downhill. We’ll say it starts at the top. Um, and, and so the technical leadership at that laboratory.

Is flawed and problematic, and the only thing that’s gonna help at this point is for the accrediting body to force change because scientifically, there have been many voices, critical voices of the work that’s been coming out of that laboratory and. They’ve been ignored, largely ignored and, and minimized.

Um, I’ve, in responses to reports that I’ve written, I see that Caroline Hor reduces my, my qualifications and my experience in the field to the four years that I spent at a publicly funded government crime lab. And, you know, it’s, it’s, that is gonna continue to happen with everyone who’s critical. Of the work that’s coming out of that lab.

And so somebody with, you know, some authority has to step in there to stop what’s happening.

Aaron Olson: Yeah. Yeah. Why do you think there is such pushback on, uh, outside criticism or, uh, you know, critique of something instead of trying to do better?

[00:19:14] Systemic Issues and Human Factors

Aaron Olson: There’s, there’s almost, uh, the opposite reaction of, of, you know, we’re the good guys, you’re the bad guys, and this is, this is how it’s done.

I think that comes from,

Tiffany Roy: that comes from human factors. This is just a real, this is mental at this point. Right. And I think it’s done in Kruger, if I’m being honest, because admitting that there is a systematic problem is devastation to these people, to their interests, to their livelihood, and also. DNA is very powerful and to think that under your watch there could be hundreds of thousands of cases that were flawed, where people could be convicted wrongfully be for your failure to lead and to ensure technical accuracy.

That’s something that people are un judges are unwilling to accept that, um, that their rulings could be based on flawed science and they don’t wanna overturn convictions based on this stuff. These people have. Real interest skin in the game and admitting the problem is adverse to their own personal interests and they’re smart, right?

I would never say that I think Marilyn Hoen Dorn is stupid, but it is a very difficult task to admit, an extremely egregious mistake, and that’s what’s occurring at Minnesota BCA. These are just human people that run these labs and they’re susceptible to all of these cognitive. You know,

interactions, we’ll call ‘em, I don’t wanna call ‘em biases, you know, but there’s a lot of cognitive science that goes into leadership in situations like this. People who run hospitals, the people who run Boeing, um, these are, these are things that we’ve observed, you know, in these leadership roles and other areas.

Surgeons, you know, um, but they’re just regular human people and trying to. Wrap your head around a very serious errors is something that it’s averse to their own human interests. Like I have, um, a case, a really serious case that involves microscopic hair analysis and an expert from the FBI Overstated the microscopic hair analysis with no forensic DNA testing four times in four separate trials.

And in the end, in the fourth trial, the only evidence that existed physical evidence was this overstated hair comparison. Um, and this expert from the FBI who no longer works there, but he works. He works at George Mason University, seems Joseph Dino. And in this death row case, he continues to defend language in all four trials and the FBI themselves.

Investigated these transcripts and sent to Brady notification stating that they identified in the report and all four trials over statements, and he still continues, even though it was his own colleagues that identified this problem and stated it was problematic and notified the lawyers involved. He still maintains that he believes that what he said was appropriate because he could be sued.

If he admits that there was a problem, um, even in the face of all that evidence, even in the face of his own colleagues telling him, this is a problem, you’ll not admit it. And he’s positioned at George Mason teaching forensic science students now, still today. And this client, Gerald Murray, is on death row.

Florida, the state of Florida seeks to execute him based only on the flawed words of Joseph Dino. And I can’t wrap my brain around it, but I’ve never been faced with something that serious that, you know, I would need to protect my own human brain from dealing with that understanding that I, that I did something that caused something like that.

Aaron Olson: Yeah. Yeah. So what’s the path forward?

[00:23:25] Advocating for Forensic Oversight

Aaron Olson: Where do we go from here?

Tiffany Roy: I advocate on every platform that I’ve ever been given for real meaningful forensic oversight, like in, in the likeness of the Texas Commission on Forensic Science. And, and those state commissions are not perfect. Um, but the closest thing we have to a model for real meaningful forensic oversight that will.

Be able to address issues like this are oversight bodies that have qualified forensic scientists and lawyers and other criminal justice stakeholders on them that have statutory power to step in and address a problem, a scientific problem from a scientific perspective, such that the scientists don’t have to convince a lay judge through a lay lawyer.

That there’s a real scientific problem. It’s just scientist to scientist. I make my case, I would win a lot more than I do in court because I’d be, they’d be evaluating the science itself instead of the makeup on my face. Or, you know, the fact that I’ve been in private practice, you know, for half of my career and not in the government crime lab, you know, as a prosecution witness.

So there’s a lot of things that go into courtroom presentation that would. Wouldn’t play a factor in, you know, the gatekeeping if we had real meaningful forensic oversight. And we can’t wait any longer for that. And I think we need it at the state level. Every single state should be reaching out to the Texas Commission and looking at the language and the laws to implement that.

Um, there’s no absolutely no reason. I live in the state of Florida and I practice in the state of Florida. A great deal and nail technicians that perform my French manicure have more oversight and regulation than the DNA experts that are interpreting evidence and testifying In cases where this state seeks to execute those defendants, we kill people in Florida at a breakneck pace.

More than any other state we’re exercising capital punishment. That’s a very real thing here, and there’s absolutely no oversight of these forensic scientists except for A NAB, and I’ve just described how effective that process is for affecting real change. And I have complained about laboratories here in Florida, and I have escalated those up to A and a B, and they have stepped in and helped in the past.

They don’t always ignore me, but. I practice at a high level, and unless there’s somebody being retained by A NAB, that’s not Bradford Putnam, you know, that has real expertise in forensic DNA, they’re gonna miss these things that I’m describing. Marilyn Hoor is missing it and she. Is smart and has specific training in this area.

So how is Bradford Putnam, who I don’t even know, what kind of training and expertise he has, how is he going to investigate something so scientifically complex that I’m saying this whole laboratory full of people isn’t getting it, but A NAB is gonna get it. Like that’s, this is, it’s not, it’s, it’s no one guarding the hen house.

It’s like. A hen guarding a hen house and mm-hmm. And they can’t, we cannot self-police. So oversight bodies and commissions, these are absolutely necessary. And another thing I advocate for staunchly is. Deposition in criminal cases, and that needs to be legislated. Um, in Florida, we have mi It’s part of routine criminal discovery that we get to depose experts, um, in advance of trial and in so many of these cases.

This stuff is readily discoverable Li listening to the testimony. Right? So the testimony that was presented to Pam King, if we had an opportunity to go before her, her, and have this expert acknowledge Yes, I, I didn’t follow the procedures here. Yes, I didn’t follow the procedures there. These, these lawyers in Minnesota would.

Would be able to, with the help of another, you know, another expert, identify these issues and then have the testimonial evidence to go to a hearing and say, Hey, look, this should be excluded. We don’t, you know, they, they get that ammunition before they start the Daubert process. So a lot of the problems, many of the problems I see in forensic DNA deal with overstatements or misstatements and, um.

Deposition helps me to identify the scientists who know what they’re talking about and make sure that the evidence that’s gonna come in on the record, right? Because our reports don’t come in on the record, nine times outta 10. They’re hearsay. So. The expert describing their results and their opinions.

That’s the evidence. And that evidence needs to be scrutinized before it’s ever presented to the jury to make sure it’s as good as it can be, and to litigate these issues before it comes, before the people who are gonna be the legal decision makers. So oversight, real meaningful oversight at the state and federal level, and deposition of experts in criminal cases.

Aaron Olson: Yeah.

[00:29:02] Conclusion and Final Thoughts

Aaron Olson: Well, Tiffany, I appreciate you taking time outta your day to come on the podcast. Do you have any final thoughts that you wanna leave listeners with before we end the call?

Tiffany Roy: Um, no, I think I’ve said, I’ve said enough.

Aaron Olson: I appreciate it so much. Thanks for coming on the podcast today.

Tiffany Roy: No, thanks for having me.

I recently received some unexpected and welcome news. My article, Errors in Toxicology Testing and the Need for Full Discovery, co-authored with Charles Ramsay, was featured on the Most Downloaded list on Forensic Science International: Synergy’s website.

Seeing our article recognized among the most downloaded pieces is both humbling and gratifying. It shows that this topic resonates with people who care about accuracy, fairness, and scientific integrity.

Why We Wrote the Article

During nearly two decades in forensic toxicology, I have seen how much the outcome of a case can depend on the smallest details. Calibration records, control charts, and data interpretation all play a role. A small oversight can mean the difference between an accurate conclusion and a serious mistake with real consequences.

Chuck and I wrote the article to draw attention to a persistent problem. Even experienced experts can make errors when the information provided in discovery is incomplete.

Defense attorneys often receive limited data, missing key materials such as raw results, method validation reports, or quality control documentation. Without those, it is difficult to properly evaluate the reliability of a test result.

Our goal was to encourage a stronger culture of transparency.

Why Transparency Matters

Toxicology is a science rooted in numbers, but those numbers do not exist in isolation. Results must be interpreted in context, taking into account the analytical process, the assumptions made, and the method's limitations.

When discovery is incomplete, that context can be lost.

Transparency protects the integrity of the science and helps ensure that legal decisions are fair and evidence-based. It benefits both the laboratory and the justice system as a whole.

A Broader Conversation

The fact that this editorial has become one of the most downloaded articles tells me that many in the forensic community are ready to talk more openly about these issues.

Quality assurance, discovery practices, and data transparency are central to the credibility of forensic toxicology.

A Personal Note

I am truly honored by this recognition and grateful that people are reading and sharing the article.

Thank you to everyone who has read, shared, and discussed the article!

You can read the full paper here:
👉 Errors in Toxicology Testing and the Need for Full Discovery (Forensic Science International: Synergy, December 2025)

I’m pleased to announce that I’ll be presenting at the 78th Annual Scientific Conference of the American Academy of Forensic Sciences (AAFS) in New Orleans this February. My presentation, “Errors in Toxicology Testing and the Need for Full Discovery,” will take place on Friday, February 13, 2026, from 9:00 to 9:45 AM.

This presentation is based on a paper published in Forensic Science International: Synergy, co-authored with defense attorney Charles Ramsay, that documents notable toxicology errors we’ve collected over a combined 48 years in the field. The research reveals systemic vulnerabilities that have affected thousands of criminal cases across multiple jurisdictions.

The Scope of the Problem

While toxicology is often viewed as one of the more objective forensic disciplines due to its foundation in analytical chemistry and quantitative measurements, our research demonstrates that it remains vulnerable to errors ranging from technical failures to deliberate misconduct.

The cases we examined fall into distinct categories: traceability errors, calibration failures, discovery violations, maintenance problems, source code defects, fraud, interfering substances, reporting errors, laboratory contamination, and chain of custody breaches. What emerged were troubling patterns that reveal systemic weaknesses in how forensic toxicology is practiced and overseen.

Patterns That Demand Attention

Errors Persisted for Years

Many of the errors we documented went undetected for extended periods. The District of Columbia miscalibrated its breath alcohol analyzers 20-40% too high for 14 years before a new employee discovered the problem. Maryland’s laboratory used scientifically invalid single-point calibration from 2011 onward, somehow passing accreditation visits in 2015 and 2019 before being cited for non-conformity in 2021.

External Discovery, Not Internal Controls

Perhaps most concerning is that errors were typically discovered by external sources rather than internal quality assurance systems. Defense attorneys, whistleblowers, and new employees, not established laboratory personnel or accreditation bodies, identified the problems. This pattern suggests that self-monitoring systems are insufficient and that laboratories can develop insular cultures resistant to critical evaluation.

Systematic Discovery Violations

The Massachusetts Office of Alcohol Testing maintained a “longstanding but unwritten policy” of withholding worksheets documenting failed calibrations. When this came to light, approximately 27,000 drunk driving cases became eligible for new trials or withdrawn guilty pleas due to what the Massachusetts Supreme Judicial Court called it “egregious government misconduct” and “a disturbing pattern of intentionally withholding exculpatory evidence year after year.”

This wasn’t an isolated incident. In Arizona, forensic scientist Gregory Ohlson, with 40 years of experience, was forced into early retirement after testifying that full disclosure of batch data from blood alcohol analysis could reveal accuracy problems. In Idaho, courts initially excluded evidence of calibration failures, requiring defendants to have expert witnesses even to cross-examine state witnesses about the issues.

Retaliation Against Whistleblowers

When problems were identified internally, those who raised concerns often faced retaliation. Gregory Ohlson’s supervisors told him he needed to change his testimony to “align” with other laboratory scientists. Vermont toxicologists Darcy Richardson and Amanda Bolduc documented that a technician was manipulating breath alcohol analyzer certification results, yet the laboratory initially dismissed their allegations.

Real-World Consequences

The impact of these errors extends far beyond laboratory walls. In the Randox Testing Services scandal in the UK, fraudulent toxicology testing affected over 10,000 criminal cases across 42 police forces between 2013 and 2017, spanning road traffic offenses, sexual offenses, violent crimes, and unexplained deaths.

Clinical laboratory errors have torn families apart. Multiple mothers, Eileen Bower, Elizabeth Mort, and Elizabeth Eden, had their newborn infants removed from their custody based on false-positive opiate screens triggered by consuming poppy seeds. These separations occurred because laboratories used inappropriately low cutoff thresholds (300 ng/mL versus the federal workplace standard of 2000 ng/mL) and failed to conduct confirmatory testing.

The Motherisk Drug Testing Laboratory scandal in Canada led to over 35,000 flawed hair drug tests between the late 1990s and 2015, resulting in wrongful removal of children from families. The laboratory operated without forensic accreditation and misused screening tests as confirmatory evidence, a practice described by an independent review as something “no forensic toxicology laboratory in the world” would do.

The Discovery Dilemma

These cases reveal a fundamental tension in forensic science between supporting prosecution and maintaining scientific objectivity. The prevalence of discovery violations suggests many forensic laboratories either misunderstand or deliberately circumvent their legal obligations under Brady v. Maryland, treating themselves as extensions of law enforcement rather than as scientific institutions bound by ethical and legal duties to disclose exculpatory evidence.

Breath alcohol testing presents unique challenges. Unlike blood or urine samples that can be retained and retested, breath samples are destroyed during analysis. This ephemeral nature makes the disclosure of digital data and calibration records essential. Without access to complete analytical records, including expirograms, flow rates, and real-time data, independent experts cannot properly verify whether tests were properly conducted.

Source Code: The Invisible Problem

Software defects present particularly insidious challenges because they can affect thousands of tests while remaining invisible to operators. We documented programming errors in breath alcohol analyzers across multiple jurisdictions:

• Massachusetts: The Dräger Alcotest 9510 was programmed with tolerance ranges that didn’t match state requirements, requiring manual verification and introducing human error

• Minnesota: The Intoxilyzer 5000EN had a programming error, causing valid samples to be rejected; the laboratory received a patch in 2007 but didn’t install it to avoid drawing attention

• New Jersey: Independent analysis of the Dräger Alcotest 7110 source code revealed thousands of programming errors using outdated methodologies

• Washington: Software issues caused inconsistent, invalid sample message rates, fluctuating from 4.3% to 40.5% across different versions

Many jurisdictions resist source code disclosure, citing trade secret protections. Yet without independent verification, these defects remain hidden.

The Path Forward

Based on our analysis, several reforms are essential:

Transparency Through Online Discovery Portals: Laboratories should provide online access to validation studies, standard operating procedures, maintenance records, quality assurance reports, and incident documentation. Massachusetts State Police implemented such a portal following their breath testing scandal; other jurisdictions should follow.

Mandatory Retention and Disclosure of Digital Data: All calibration records, chromatograms, quality assurance charts, instrument maintenance logs, and metadata should be preserved and made available. For breath alcohol testing specifically, digital expirograms, flow rates, and real-time monitoring data must be retained.

Accessible Data Formats: Laboratories should provide data in formats that facilitate independent analysis, such as tabular data in spreadsheet formats rather than PDFs.

Source Code Access: Source code for analytical instruments should be available for independent review under appropriate protective orders, or manufacturers should create open-source repositories for public review.

Laboratory Independence: Forensic laboratories should strive for independence from law enforcement agencies, as recommended by the National Academy of Sciences.

Rigorous Accreditation: Accreditation bodies must conduct more thorough assessments. Maryland’s laboratory passed multiple audits while using invalid single-point calibration, demonstrating current oversight inadequacies.

Whistleblower Protections: Legal protections must be established for forensic scientists who report problems or violations of discovery. The retaliation faced by those who speak up creates a chilling effect that perpetuates errors.

Regular Third-Party Audits: Beyond accreditation requirements, independent experts should conduct regular audits of laboratories. Many documented errors persisted for years and were only discovered through aggressive discovery efforts.

Looking Ahead

The forensic science community has made tremendous progress in improving laboratory practices and standards. But there’s more work to be done, particularly regarding transparency, accountability, and protecting those who identify problems.

My hope is that this presentation will contribute to an ongoing conversation about strengthening forensic toxicology. By examining past errors honestly, we can develop policies that prevent similar mistakes and ensure the results society relies upon are truly trustworthy.

These aren’t just technical or procedural issues; they’re fundamental to justice. When toxicology results influence life-altering decisions in criminal prosecutions, child custody matters, and other legal proceedings, accuracy and transparency become moral imperatives.

If you’re attending AAFS 2026 in New Orleans, I’d welcome the opportunity to discuss these findings and potential solutions. And if you’ve experienced similar issues or have insights to share, please reach out.

The 78th Annual AAFS Scientific Conference will take place February 9-14, 2026, in New Orleans, Louisiana.

The full paper, “Errors in toxicology testing and the need for full discovery,” is published in Forensic Science International: Synergy and available as open access.

When faced with serious scientific errors, responsible laboratories respond with transparency. Unfortunately, the Minnesota Bureau of Criminal Apprehension (BCA) appears to be doing the opposite.

According to defense attorneys, after the recent breath alcohol scandal, the BCA changed its discovery policy so that routine breath-test discovery materials, including the Control Change and Form 31, can’t be released without both prosecutor approval and supervisor approval.

These aren’t sensitive documents.

They’re calibration and quality-control records that show whether instruments used for DWI testing were functioning properly.

The entire database should be freely available online for all to see.

These are the very documents Chuck Ramsay and I used to discover the errors in Minnesota’s breath testing debacle.

So why should a prosecutor have to approve the release of laboratory records in the first place? Science should be governed by evidence, not legal strategy.

Other States Get It Right

Minnesota’s new policy is especially troubling because it moves the state in the opposite direction of national best practices.

The National Academy of Sciences’ 2009 report, Strengthening Forensic Science in the United States: A Path Forward, warned that forensic laboratories operating within law enforcement agencies face inherent conflicts of interest.

It called for independent oversight, transparent data practices, and public access to scientific records to prevent exactly this kind of problem. More than fifteen years later, Minnesota has still not adopted those recommendations, and this new policy moves the state even further away from them.

A recent survey found that 26% of states had online records available for discovery.1 For example, in Alaska, after a notable dry gas scandal, the state laboratory created a searchable database of breath-test instrument certifications and reference standards. In Massachusetts, following a major forensic crisis, officials launched an online portal providing public access to maintenance logs, certifications, and even software updates.

These states recognize what Minnesota still refuses to: transparency builds trust.

Instead of Fixing the Problem, the BCA’s Fixing the Optics

Dozens of DWI cases have already been dismissed in Minnesota because officers used the wrong type of dry gas reference material during calibration checks.

Yet instead of opening its records and inviting outside review, the BCA’s response has been to limit who can even see those records.

That doesn’t fix the science; it just shields the institution.

If the BCA truly wants to restore public confidence, it should follow the lead of Alaska and Massachusetts by publishing all calibration, validation, and maintenance data online.

Transparency Isn’t a Risk — It’s a Safeguard

Science advances through openness, replication, and accountability. When a state laboratory treats its basic records like state secrets, the public is right to lose trust.

Real reform doesn’t come from controlling information. It comes from inviting independent experts to see it.

Yesterday, on October 13, 2025, at 5 PM, Superintendent Drew Evans of the Minnesota Bureau of Criminal Apprehension (BCA) held a press conference to address what he described as “human errors” in the state’s breath alcohol testing program.

The BCA’s message was clear: the issue was recent, limited in scope, and already under control.

Evans emphasized that only about 275 tests might be affected, that the instruments themselves remain reliable, and that the Bureau had acted swiftly once notified on September 12.

But the record tells a different story.

Documents, internal communications, and even a 2023 law enforcement report show that the BCA knew about this exact problem more than two years ago, and initially defended the accuracy of tests that were later proven unreliable.

Even more troubling, the BCA didn’t uncover this issue through its own internal quality control processes.

It was defense attorneys and their independent forensic experts (Chuck Ramsay and me) who identified the dry gas cylinder errors, not an internal audit, not a BCA inspection, and not any proactive review by the agency itself.

The press conference was meant to restore confidence. Instead, it exposed just how incomplete the official narrative remains.

The BCA Knew Long Before September 2025

At the press conference, Evans said the Bureau first learned of the DMT dry gas problem on September 12, 2025.

But that claim doesn’t line up with the evidence.

The Olmsted County Sheriff’s Office report from early 2023 documents that the BCA already knew about this issue more than two years ago.

In that report, an officer wrote that the BCA “advised that the breath tests performed on the DMT between 02-27-2023 and 03-02-2023 were still accurate tests even though a PBT dry gas cylinder was installed in the DMT.”

Rather than investigate or issue a statewide alert, the BCA stood behind those results. Only after Chuck Ramsay and I published our June 2025 peer-reviewed article exposing the problem did the Bureau reverse course.

“Case by Case” vs. Categorical Rejection

Evans said each test would be reviewed “on a case-by-case basis.” But that statement is also inconsistent with the BCA’s own communications.

In Aitkin County, BCA scientists wrote that they “cannot support this type of testing” and “cannot testify in court to the accuracy of these results.”

That’s not a nuanced, individual review; it’s a categorical rejection of an entire set of tests performed under invalid conditions.

The BCA Has Started to Act — But Only After Public Pressure

In fairness, some of the steps Superintendent Evans announced reflect recommendations I outlined in my earlier post, “The Five Whys: A Root Cause Analysis of Minnesota’s Breath Testing Failures”.

The BCA has now decided that:

• Only trained BCA scientists and technicians will perform dry gas cylinder changes.

• Local law enforcement operators will no longer have access to the cylinder compartment.

• A lockout procedure will be implemented to prevent unauthorized changes.

These are important first steps, and they directly mirror some of the solutions I proposed.

But what’s still missing are the two most important reforms: independent external review and public transparency.

Without those, the same problems that went unnoticed for years can simply resurface in another form.

What Was Missing

Several key issues went unmentioned in Evans’s press conference, and their absence speaks volumes.

• No independent oversight.
  The BCA continues to investigate itself. There was no announcement of an external audit, third-party review, or invitation for independent experts to verify the quality assurance data.

• No commitment to public transparency.
  Evans did not address whether the BCA would make quality-assurance data publicly accessible, despite national recommendations for forensic transparency.

• No acknowledgment of past cases.
  The BCA’s focus remains on the currently identified 275 tests. But the same equipment has been in use for more than a decade. If these issues date back to 2023 or earlier, what about the thousands of past DWI convictions that may have relied on similarly flawed testing?

The Real Lesson

Evans’ press conference was meant to project confidence. Instead, it underscored a deeper truth: Minnesota’s breath-testing program still lacks independent oversight, public transparency, and full accountability.

Real progress will come when that control is balanced with independent verification, when outside experts can access and evaluate the data themselves. Only then can the BCA fully demonstrate the integrity and transparency it says it values.

The BCA defines Integrity as “the cornerstone of public trust” and a commitment to “always do the right thing.”

Living up to that value now means more than reassuring words at a press conference.

Automated Transcript of BCA Press Conference (not checked for errors)

[00:00:00] Drew Evans: Good afternoon, everyone, and thank you for, uh, joining us here today. My name is Drew Evans. I’m the superintendent here at the Minnesota Bureau of Criminal Apprehension. There’s been a lot of interest in some recent, um, guidance that we’ve put out to Minnesota law enforcement on inspection of our DMTs or data master, uh, transportable machines is what they’re referred to and what that means in the impact of Minnesota law enforcement. Before I do that though, I’d like to give a little bit of background on the instrumentation to level set exactly what these, uh, instruments do and what they don’t do for us. In Minnesota, there’s currently 220 instruments that are deployed across the state of Minnesota and approximately 4,500 users that utilize, uh, these instrumentation to conduct breath alcohol tests on individuals that are suspected of driving while intoxicated.

[00:00:53] In that process, they all go undergo extensive training on how to use the instrumentation for our law enforcement partners. And then there’s some pieces that go with this that have brought you here today. What we’ve uncovered in the, once we were first notified about this is that there’s been a number of human errors that we’ve identified with these instrumentations in particular when changing out a dry gas cylinder that is used for a control test.

[00:01:17] And in that process, it’s important that that’s done correctly. Uh, and with, uh, and some errors have been discovered, uh, in that process. Minnesota users every single year conduct approximately 19 to 20,000 tests, and we’re at 15,000 tests across Minnesota. So far in this process that we’ve identified where there’s been human errors in terms of changing out these gas cylinders that we have approximately, um.

[00:01:41] 275 tests that may be impacted. That’s what’s important to know in this, that every one of those cases need to be individually examined by, uh, prosecutors of the Attorney General’s office that are working through that to determine whether or not that test was impacted. Here’s what we’re doing in this process last Friday.

[00:01:59] We notified all Minnesota, uh, users of this instrumentation that they need to check the instrument. And it’s important for everybody to know that these instruments at those locations across Minnesota are at locations to be used by any of the users that may be using it in there. And what that means is a particular agency, or in this case when we’ve identified counties or locations where these machines might be the heirs that occurred, may or may not have been done by those agencies.

[00:02:28] Part of the agreement with these is to ensure that everybody has access to the machines, is that all law enforcement in the area has the ability to use the machines. So it’s an important fact that when this airs with changing out the cylinder may have been done by another entity. When we’re working through that process.

[00:02:44] The inspection that we asked is we did not take the fleet completely offline. What we did is we asked for the fleet not to be used any of the instrumentation until a simple five minute check can be done. What that involves is removing the cylinder and ensuring the information that is on the cylinder, which I’ll show you in a moment, is accurate in the machine, and that a control change test is performed to ensure that it matches the information after they reinsert it in their process.

[00:03:10] This has not impacted Minnesota law enforcement’s ability to conduct DWI enforcement across Minnesota. Many of the machines were, uh, examined in that period, and they can go right back online because they’re accurate in the testing process and they can use the machines again, or law enforcement if a machine is not available, can engage in toxicology testing, which we also have that laboratory here at the BCA as well to test alcohol content in, uh, blood and urine and other substances, which we do on a regular basis. I wanna be clear that these instruments, we have complete faith in the instrumentation and the accuracy of the test results.

[00:03:43] These areas that occurred in this process are a result of this change, not several factors that might have been in that process. So what we’re doing going forward after this inspection is that in order to, um, ensure. That, uh, we have less people working on these and changing ‘em. Again, I noted there are 4,500 users across Minnesota.

[00:04:02] That’s a large number of people that have to revert back to their training. That may not change these on a regular basis, where we have a calibration team that manages and inspects and maintains this fleet here at the BCA. They will take over going forward the changing those gas cylinders. It’s not that law enforcement doesn’t do this well.

[00:04:18] Tens of thousands of cases every single year, and they change out these cylinders. It’s that when we learn of some errors, we think through critically here at the BCA, how we can eliminate those. And by bringing this change process into a fewer number of people, we’re able to eliminate some of those errors along the way.

[00:04:34] We’re working on that as quickly as possible, uh, across the state of Minnesota, and we’ll also make sure that those cylinders are no longer accessible by anybody other than the scientists that work here at the BCA and technicians that are working on these instruments every single day. I want to thank our Minnesota law enforcement partners for paying prompt attention to the requests came on a Friday, coming into a busy weekend, but once we learned of additional locations where there were a variety of errors from either the wrong cylinder.

[00:05:02] Uh, being installed that was not provided by us. We provide the cylinders or data entry error in that process that we felt it was incumbent, that we get the information out as quickly as possible so that our law enforcement partners can inspect ‘em. ‘cause the last thing they want is to have a, a breath test that could potentially be impacted as they’re working diligently every single day to remove impaired drivers from Minnesota roads across Minnesota.

[00:05:25] I’m gonna step over to the other table just quickly to show you what I’m referencing and then take some questions. So this is a DMT machine that are used across all of Minnesota. This is our current fleet that we’re using, and the cylinders in question are these cylinders here, they have information printed on the outside of the cylinder.

[00:05:44] These are then input into the back of the machine, inserted into this machine, and then the information is put. If any of this information, I shouldn’t say any if some of this information is entered incorrectly. It could create a challenge for this and the reliability of the particular test. However, there’s other pieces of this that could be entered incorrectly and we’ll show that error in the process, but it may not impact the actual reliability of the test.

[00:06:11] That’s why we say it’s important that we work through each case individually with prosecutors and the Attorney General’s office and the implied consent side to determine whether or not the test is actually impacted going forward. This dry gas is provided by the BCA. And we provide these for all of the instrumentation across the state of Minnesota in that process.

[00:06:33] With that, I would be, uh, happy to, to an

[00:06:43] Audience: time period there.

[00:06:47] Drew Evans: Well, part of what we asked for in this process is to ask to this inspection. So to date, we have not received any additional, uh, contact from agencies saying there’s different challenges with that. However, of the five counties that we’re aware of that have had some challenges, they’re all slightly nuanced.

[00:07:05] Issues. They’re all slightly different, so we need to look at them one-on-one as we go through to determine whether or not it impacts the actual case. We are first notified of the first issue on September 12th, but we’ll be working as part of this inspection process to determine if any others have challenges with them.

[00:07:22] Also, it should mention that all machines across Minnesota are calibrated in our laboratory once a year. And so we see the machines as they come in, and the part of the inspection process is examining the cylinder that’s in there when we receive that. And we had not seen the same issue that we’ve seen in this particular case going back.

[00:07:40] So the timeframe we’re looking at right now is looking at the current fleet that’s deployed within that period of time, and then we’ll address any additional issues as they come up, uh, through the process as people, you know, mount any challenges or questions or inquire about the various machines and the, the testing across Minnesota.

[00:07:59] Audience: Aware of this last month, what was the reason for the.

[00:08:11] Drew Evans: Yeah. So the question was, uh, for others is that the, if we were aware of this in September 12th, why, uh, was the review recently ordered as part of this process when that first instrumentation came in or that the notification as part of that process? We had no reason to believe it was a more widespread problem with the instrumentation.

[00:08:31] As we’ve been notified of some of the others that I said, they’re all unique instances that appeared to be. Uh, individualized and as we learned over the last, uh, as we’ve been working through the review on our own, we determined that this potentially could be more widespread given that there was similarity between some of the issues.

[00:08:48] And that’s why we issued the request, uh, to inspect all these machines before using them. Further to make sure that that data entry error did not occur in any of the others. It’s important to know that this instrumentation, you know, is, um, uh, reliable and it’s, it has, uh, the testing itself. Uh, it is in terms of how the instrumentation works, uh, is a reliable machine and it works well in that process and those data entry error may or may not actually impact the validity of the results in that process.

[00:09:15] So it takes us some time, as I said, there’s, you know, 20,000 tests a year to. Go through some of the data that we have available to determine whether or not this was something that we needed to do inspection, or if it was one or two off issues that we identified by self-reporting. I’ll note one of the counties, even after this happened, they were doing their own change process that identified for us and they followed their training.

[00:09:36] Exactly. They changed it out. They notified us that there was a problem with this, and we addressed that in there. That was the, the second two that we were working on in the. The third actually in the process that we’re notified of in that process. So, uh, certainly, uh, the checks and the training and the quality controls we have in place worked in some instances and we wanted make sure that others where it may not have that we go forward with that process forward.

[00:10:03] Audience: Is there any sense of how this happened?

[00:10:08] Drew Evans: Well, again, with, you know, 4,500 users across Minnesota that are using this instrumentation that have to look through that process, human error, whenever there’s humans involved in something, there’s always potential for human error. That’s part of why we’re looking at this process now and, and narrowing the number of people that will handle this, that do this every single day, and that their full-time job is the maintenance, inspection and repair of these machines, so that, that’s reviewing it.

[00:10:33] Again, with that many users and human error, once this issue’s been identified for us, uh, it’s not that law enforcement doesn’t do it correctly. There’s thousands and thousands of tests over many years where they’ve done a great job with this. It’s a matter of looking at if we identify an issue, what other ways can we work on to support our law enforcement partners across Minnesota to make sure that their, uh, testing is not impacted by a simple human error like this.

[00:10:59] So right now we know of, um, five different situations, but we’re continuing to look at that and certainly that may be additional as we ask them to inspect. We just asked them on Friday to inspect. We didn’t give them a timeframe to do that. We asked ‘em to inspect, not use the instrument until they have the ability to do that and contact us with any, uh, challenge problems that they see.

[00:11:18] And we have not heard from anybody yet, but it could, it could, we could hear from others and that’s fine.

[00:11:23] Audience: How many? 220.

[00:11:27] That number is at 275.

[00:11:30] Drew Evans: Yeah, it certainly could grow. Again, we haven’t been contacted today and we issued this and you know, we’ve certainly heard from some law enforcement, we’ve heard, we fielded questions all weekend long from law enforcement asking about this process.

[00:11:42] So we know they had ah, jumped on this and were very prompt, uh, to, to looking at these devices. So we assume that the majority of them that were quick to look at this did not find any problems with the device. But we’ll continue to look at that. And then also the data from the devices in the past.

[00:12:00] Well, great question. So I mean, the, the, it’s a three day training now, 24 hours of training that go into the proper use, uh, in administration of breath alcohol tests in Minnesota. But part of that training is going to be, don’t, uh, remove the gas cylinder. So we’re going to do that in that process and that’ll eliminate most of this particular issue because we will be the ones putting all that data in and doing that day in, day out.

[00:12:23] Uh, so that we think is an easy way for us to be able to address this issue on that. But the training also as they go through. It’s very detailed in terms of how they go through each step. And part of our notification this week on this particular was to send out, uh, a detailed step-by-step instructions for how they would go through and, and change, do the inspection on this and, and remind them of the training in the manual about the proper changing out of that.

[00:12:48] But we are telling them do not change them at all, and we’ll be locking down the instrumentation going forward.

[00:12:59] Audience: Yeah, but.

[00:13:08] Drew Evans: Yeah, so certainly we’re under a review process right now, and that’ll be part of the process, which is to work together with the attorneys. Obviously, we can’t comment on, you know, pending litigation, and there certainly could be with these. So we’ll be doing that review working together with county attorneys and the Attorney General’s office, uh, in part of this process, looking to determine if any cases going further back would be impacted.

[00:13:32] When they’re writing numbers down correctly or, yeah, so on a canister like this, there’s a lot number, just as an explanation, there’s the alcohol concentration that’s listed here that this is originally.

[00:13:49] And then an expiration date that’s on here. Some of that information could, is then all the information is then entered into the machine so that it knows which dry gas cylinder is in the particular machine. And then in particular, that alcohol concentration. If that is wrong, it runs a control test. But these are, they have such low tolerances that it could potentially.

[00:14:11] Um, not air out in that change process if it was just transposed a bit, but it’s important for us to have all that information entered in accurately. Again, though, if some of this information, like this lot number was not necessarily entered in 100% correct, that may not impact the validity of the particular test.

[00:14:28] It has to do with some of the other data. That’s why we have to work through it on a case-by-case basis with each of the tests to determine how the attorneys want to handle the particular case.

[00:14:45] I’m not, uh, I’m aware of a couple of issues in particular with, uh, the canister not being used, uh, correctly provided by us, uh, in the past that we address with the agency, but the canister may or may not. Impact the actual validity of the results that canister doesn’t have to be provided by. It has to be provided by us, by our own guidance, but it doesn’t mean that the actual cylinder would be incorrect if it was by another third party supplier or a different canister.

[00:15:13] We do that as a quality control measure here at the BCA, so we know which dry gas cylinders are going in our instrumentation as part of our accreditation process, which is our quality standards for our laboratory here.

[00:15:27] Uh, I believe this Fleet, 2012, I believe is one first one into, uh, that. I’m seeing 20 11, 20 11, 20 12, uh, in that process. But this particular fleet’s been in, we’ve been looking at, uh, replacement fleet. It’s a decade or or more old at this point in time. So certainly that’s been on our radar for a while now.

[00:15:47] We’re working through that. And part of that process is always looking at how do we improve the fleet that’s in there, you know, with this, uh, process, obviously this is an efficient way to measure blood alcohol out as opposed to going through, uh, toxicology, which is a very accurate measurement as well.

[00:16:03] But it requires getting a search warrant, uh, to gather that so it takes a law enforcement more time. So that’s why the utility of our fleet remains in Minnesota and why we’ve looked to have these instruments across the state.

[00:16:18] Yeah, the great question. So just to be clear, question is about how any idea how long it’ll last, it lasts until they inspect the machine and ensure it’s the right canister. That’s it. So they, the, the instructions were to go back on line, it’s a five minute inspection, make sure it’s the right canister, all the information matches.

[00:16:35] And then that instrument, that particular instrument can be used again. We did not suspend the fleet hole until it was a green light by the BCA. It was make sure that you inspect this to make sure the information is accurate so it doesn’t impact any tests moving forward. And then they can use the instrument again.

[00:16:50] We have full faith, uh, in the instrumentation and the validity of the results if everything is entered correctly. One more question. So is it possible that. That there.

[00:17:08] Well, in theory, if that information, it wasn’t caught along the way, certainly there’s cases if that same error and nobody caught it, uh, certainly could be in that. Never could say that there wasn’t in that process. But what is important to know is this is a bit nuanced and technical. It doesn’t necessarily mean even if there were errors, that the test results themselves were not reliable.

[00:17:28] And so they would need to be identified and work through that process because again, while this is a, a very technical piece of this equipment, the reliability of the results really do need to be examined on a case by case basis. When we identify the a hundred plus, uh, 276 cases that we’ve identified for you, that could be impacted, that’s out of an extreme abundance of caution that we’re looking through, that we’re saying we need to get in and have.

[00:17:51] Other people take a look at this and work through these cases individually to determine whether or not they’ve been impacted. And that’s what we do in our, our laboratory. We hold ourselves to the highest standards of quality in the process, and that’s why we’ve taken the steps that we have to make sure that we are being as best a partner to our Minnesota law enforcement as we can, so that Minnesotans can trust the results and that we can ensure that impaired drivers are held accountable for their conduct.

[00:18:16] Thank you.