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Science on Trial: The Evolution of Bloodstain Pattern Analysis 

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Jeremy: Our testimony is powerful testimony. And, and, and we need to check our egos and realize that, that there is a lot of responsibility that comes with that. And, and to make sure that the words that we use are, are carefully thought, they're carefully constructed, they're rooted on objective information, they're rooted in science, and, that, that they're measured. and, and we need to, to not try and be the all-star witness, the one that slams the door for the case of either side that, that we're testifying for. My allegiance is to the science. My allegiance isn't to the case. And, and I hope that all scientists take that approach that I'm here to defend the science and not necessarily make a case. If my science and my conclusions help out the investigation, that's fine. If they don't help out the investigation, that's fine as well.

Hello, and welcome to Secrets from the Crime Lab. I'm your host, [00:01:00] Angela Tanzillo-Swarts. Had a little bit of a hiatus. Work got a little too busy for me to have time to do recordings, so I've been a little bit negligent in providing new content for you. But I wanted to share a conversation that I recently had with a bloodstain pattern analyst, Jeremiah Morris.

We had a conversation about a week ago. Now, Jeremy's with the Johnson County Sheriff's Office Criminalistics Laboratory in Kansas, and he's the technical leader in bloodstain pattern analysis. So he's been doing BPA casework since 2005, and he's a distinguished member of the International Association of Bloodstain Pattern Analysts.

He's a certified bloodstain pattern analyst through the International Association of Identification He was a member of the Bloodstain Pattern Analysis Subcommittee in the Organization of Scientific Area Committees for Forensic Science. [00:02:00] He was also part of the Scientific Working Group on Bloodstain Pattern Analysis, otherwise known as SWGSTAIN, and also the Netherlands Register of Court Experts Advisory Committee of Standardization of Bloodstain Pattern Analysis.

And he's currently the editor of the Journal of Bloodstain Pattern Analysis through the IABPA, and he's authored and co-authored three chapters in the Handbook of Bloodstain Pattern Analysis that was just published, um, I believe last year in twenty twenty-five. So brand-new, brand-new publication, hot off the presses.

I highly recommend that you check it out if you are interested in bloodstain pattern analysis. But before I get into my conversation with Jeremy Morris, I would like to share an opportunity for continuing education for legal professionals and investigators that are interested in understanding more about bloodstain pattern analysis, [00:03:00] specifically our conference that we're gonna hold centers around wrongful convictions and potential wrongful convictions, and the investigations that go into those types of cases.

And so, uh, I don't talk about it much, but I am a professor at the University of North Texas with the forensic science program. I, I teach biomedical criminalistics and forensic molecular biology, and I also do a special problems course in bloodstain pattern analysis, and we also have done another one in the past where we review post-conviction cases of actual innocence.

Now, the conference that we're gonna have in Denton, Texas, at the University of North Texas, UNT is hosting it, um, specifically the forensic science program, and we've been lucky enough to be sponsored by the College of Science so that we can host this for you. It is at [00:04:00] the Gateway Center Ballroom at the University of North Texas in Denton.

It's right off the interstate highway, so it's very easy to find. It's got its own parking lot. The program is called Bloodstain Pattern Analysis in the Courtroom: Lessons from Wrongful Conviction Cases, Contested Forensic Testimony, and Evolving Forensic Standards. And this program has been put together by a gentleman named Bill Clutter, and he is a Licensed private investigator that's done a lot of work on wrongful convictions and the death penalty.

He did a lot of that while he was in Chicago. But he founded an organization called Investigating Innocence, and this is... Think of it as an innocence project, but rather than being for attorneys that can help with indigent defense cases and cases of investigating possible wrongful convictions for the attorneys, Investigating Innocence is focused on the [00:05:00] investigators that can assist in those post-conviction investigations and helping inmates that are seeking to prove post-conviction claims of actual innocence.

So it's an organization designed for private investigators, attorneys, and also forensic scientists. Now, the private investigators that join Investigating Innocence can earn eight hours of credit toward a 40-hour certification program as a post-conviction investigation expert. And once they're certified, the PIs can offer their services to members of the Investigating Innocence network who are representing these indigent inmates.

And Investigating Innocence, it's a national organization. The Texas chapter is new, and it's headed up by a senior investigator, Mark Gillespie. Mark will be at the conference in Denton along with Bill, so please come and, and meet them and be a part of [00:06:00] this organization. It's a 501 not-for-profit. It's, it's a good cause to be involved in, especially if this is something that you are passionate about.

But I think the lessons that we can learn from the cases that are going to be discussed at this conference are essential to preventing similar wrongful convictions from happening in the future. Now, we're going to be discussing three cases specifically where people were later acquitted, one case where the gentleman served out his entire term, and one case that is still ongoing.

Three of these cases were really important 'cause they predated what, what was called the National Academy of Sciences. We call it the 2009 NAS report. It has a longer title, Strengthening Forensic Science in the United States: A Path Forward. So this was published in 2009, hence why we call it the 2009 NAS report.

So This report was quite critical of many [00:07:00] forensic sciences. BPA certainly, um, had a lot of criticisms thrown in its direction, and it came from cases like the ones we're going to discuss at the conference, the Joe Bryan case, the Julie Rae case, and the David Camm case, and these people went through multiple trials before they were acquitted.

David Camm actually went through three trials before he was finally acquitted in twenty thirteen. Now, one of the things, the things that were issues in all three of these cases are things that were specifically pointed out in the two thousand and nine NAS report. Specifically, we had uncertain interpretations, subjective judgments, disagreement among analysts and, and testimony that, that sounded more definitive than the methods that were used actually warranted, and that's a problem that we see quite often.

If you look at the National Registry of Exonerations and you can search it by the reason for the exoneration, [00:08:00] one of the things you can look at is misleading or misinterpretation of forensic evidence, and you can see that it's quite prevalent in there. Now, it's usually not alone. A lot of times it comes in conjunction with prosecutorial misconduct, but forensic scientists have a very important role to play, and I, I'm not gonna talk too much about that now because I think that my guest in this episode does an excellent job addressing that particular issue.

But I do wanna say that since the criticisms of the two thousand and nine report, the BPA community has really stepped up, and we've been conducting a lot more research, examining error rates, trying to find a way to quantify those and find the weaknesses in our processes and shore those up and understand better the limitations of the science to make sure that we're not overstating the meaning of the evidence itself. In November of [00:09:00] 2023, Dr.

John Morgan was asked by the National Institute of Justice to review and analyze the reasons for wrongful convictions. He examined multiple different forensic disciplines when he conducted his analysis, and he broke things down into five different error types. Now, type one were issues with the forensic science reports.

So the report had a misstatement of the scientific basis of a forensic science examination. So this was a lab error or poor communication. They excluded information that should have been included in a report. Type two errors, he called individualization or classification errors. So this is where the forensic science examination had an incorrect individualization or classification of a piece of evidence or the incorrect interpretation of a forensic result that implies an incorrect individualization or association.

Now, I'm not gonna talk [00:10:00] about the other three types that he addressed because the ones that he found that applied to cases that involved blood spatter, there were thirty-three that were present in the registry. Fifty-eight percent of those had at least one error. Twenty-seven percent of those involved what he termed a type two error, that incorrect individualization or classification that implied an incorrect individualization or association.

And that's largely things that were identified in these three pertinent cases of David Camm, Joe Bryan, and Julie Rea. The conference is also gonna talk about two other cases, the case of Warren Horniak and the case of Darlie Routier, which is quite an infamous case here in North Texas. So we're bringing in the investigators and the experts that worked on behalf of the defense in these cases.

Some of them worked at the [00:11:00] direction of the Texas Forensic Science Commission. So it is an excellent opportunity to get your continuing education and learn from the mistakes of others and so that we can prevent those types of issues from happening in the future. Registration is open to anyone.

Investigating Innocence members can attend for free. You just have to pay a little bit for, for lunch and parking, 'cause it is a university. There's no such thing as free parking on a university campus. I will provide a link for registration in the show notes, so please think about joining us. Again, it's November 18th, 2026 from 8:00 AM to 5:00 PM at the Gateway Center Ballroom at the University of North Texas here in Denton.

Before we jump into my conversation with Jeremy, I just wanted to remind everybody, since I've mentioned both my employer and that of my guest, that the views on this podcast [00:12:00] are the views of the person on the podcast and do not represent the views of either the University of North Texas or the Johnson County Sheriff's Office.

And now I present to you my conversation that I recently had with Jeremiah, and I hope that you enjoy listening to it as much as I enjoyed having the conversation with him.

Angela: Greetings all and welcome to a new episode of Secrets from the Crime Lab. We've been gone for a little while, but we are back, and we're going to talk about bloodstain pattern analysis, and we're gonna talk about the real bloodstain pattern analysis, not what you see on television. And with me today, I have a guest that I first met virtually by attending one of his podcasts on bloodstain classification and other types, other approaches to, how we observe bloodstains and document them and use their features to determine what types of [00:13:00] stains they are through different approaches than what we were classically trained to do.

So without further ado I'd like to introduce you to Jeremiah Morris. Do you go by Jeremy or Jeremiah? What do you prefer?

Jeremy: Yeah, Jeremy's fine. Jeremiah is when I testify or when I'm in trouble. So 

Angela: Okay, well, this is neither of those situations, so . Please, please introduce yourself

Jeremy: Well, thank you for having me, join you. I really appreciate this, and it's quite the honor. So my name is Jeremy Morris. I am a forensic scientist supervisor with the Johnson County Sheriff's Office Crime Lab, and that's in the-- on the Kansas side of the Kansas City area. I've been, in forensics for, almost twenty-five years, with the Johnson County Lab, since, two thousand and three. I've kind of been in kind of a mutt is how I describe myself. I started out in drug chemistry, did an internship in toxicology before I got hired. And then I-- in two thousand and five, I took a basic course in bloodstain pattern analysis. the reason why I did that is because, all [00:14:00] of us who were bench scientists were assigned to the crime scene unit, we didn't have anybody who did BPA.

and we had a couple of scenes where we thought it was kind of important. So, I asked if I could help start up a bloodstain team, and the lab director agreed. So I took my, my first, intro class in May, or actually June of two thousand and five, and, and that was starting a path that I did not expect.

it's been a fascinating path. outside of BPA, I, I, I did trace evidence for several years, and then a little over five years ago, I became supervisor of the crime scene section. for BPA, I was I had a a fortunate opportunity to be a guest at SWGSTAIN I think it was in two thousand and eight, and, was able to be their guest for a couple of their meetings, and then I became a member in two thousand and nine. And I-- so I was a member until, SWGSTAIN was replaced by OSAC, and, I was on the first [00:15:00] OSAC subcommittee for BPA, and I served there for six years. so there was-- it was-- it-- being part of a standard-setting organization and, and helping draft the standards is absolutely fascinating. In addition to that, I am, I'm the current editor of the Journal of Bloodstain Pattern Analysis through the IABPA. And, I, I've given a couple of webinars, as, as you mentioned already. had opportunities to, to kind of give some presentations. I have had some fantastic mentors over the years and, and I'm-- anything that I've accomplished is because of, of their patience and their, and their mentorship and them sharing their wisdom allowing me to just kind of stand on their shoulders for a little while. this-- I enjoy this discipline. I love it, and then my goal and my hope is to make it better 

Angela: You said a few things in there. I wanna make sure our audience is, is familiar withit. So that's a, that's a broad area of expertise, and then you have an additional focus that you zoomed in on with the bloodstain [00:16:00] pattern analysis. And you mentioned SWGSTAIN, and so for those in the audience that aren't familiar with that, that's the Scientific Working Group on Bloodstain Pattern Analysis.

And they don't, they don't exist anymore because they were absorbed into the Organization of Scientific Area Committees. would you like to speak a little bit about that transition from one organization to another and why that happened?

Jeremy: Yeah. So, the, the organizations are similar, but they're not entirely equal. the, the SWGSTAIN was an international organization. we had, a-- probably 50% or more of our membership were not from the United States. we had a number of people who were from the UK, we had guests from South Africa, we had several from Australia and New Zealand and, and a lot of Canadians that were part of this. it really was truly an international collaboration. And, when, when there was movement after the, the [00:17:00] NAS report, National Academy of Sciences report of forensic science in 2009, there began this push for, a national standard-setting body within the United States to kinda help this consolidate the work of forensic science in the US. most of the SWGs, these scientific working groups, were replaced by, OSAC, as you mentioned, which was the Organization of Scientific Area of Committees in Forensic Science. OSAC is primarily, or if not entirely, a US-based organization now. All, all of the members are US, practitioners or, or, experts, practitioners,educators or other, other private consultants. but the members are from the United States, and we can bring in guests from outside of the US, but the, the international component of OSAC is significantly smaller than what we had, with the SWGs 

Angela: That's where organizations like the [00:18:00] IABPA, the International Association of Bloodstain Pattern Ana- Analysis comes into play, right? I mean, they don't-- we're not a s- they're not a standards body, but it certainly does keep those, the communication lines open, as it were.

Jeremy: Yes, and there are, and there are other international groups that help out. The 

Angela: Mm-hmm

Jeremy: has, their own standard, European has their groups, and New Zealand and Australia work together as well 

Angela: One of the, the things that you mentioned while you were talking about was the NAS report that came out in 2009. and that's, that was the... I, I can't remember if it was something that they stated in there or if it was an action that arose in consequence of that report that the National Institute of Standards and Technology was directed to form the OSAC committees.

And you're right, a lot of... The, I think the only scientific working group that remains is, SWGDAM, which is the one that's specific to DNA [00:19:00] analysis,so they still function, but they're very much intertwined with the, the OSAC w- as far as, you know, standards developments and stuff. But they are, they, they do still exist, but everybody else is part of the, the NIST, organization now.

So, in, and I'll, I'll tell the audience more about this when I, when I record the intro, but we are here in, at, at the University of North Texas in Denton. In November, we're going to be having a, bloodstain pattern analysis, conference where we're focusing in on some wrongful convictions and some of the experts that worked on those cases and the investigators that worked on those cases, in an effort to get those convictions overturned.

those cases were, I would say, three of the most poignant cases, that predated the criticisms that were in the NAS report from 2009. [00:20:00] And I'd like to talk to you, not about those cases specifically because, you know, our conference is gonna talk about that in, in, in November, but more about, I think what you call, what you've called in the past learning points.

Like, what were the things that we learned from these cases and other things since then? The comments, the criticisms that the NAS report leveled that were specific to BPA. They gave a lot of commentary on many different forensic disciplines, but, 

Jeremy: Mm-hmm. 

Angela: BPA felt like they got beat up a little bit in the process, I think.

but I would say that, 

Jeremy: with their comments, that's 

Angela: yeah, so, but so let's talk a little bit about what were their criticisms and what you've seen as a response in the BPA community to addressing their concerns.

Jeremy: Certainly. So one of the-- There, there were a number of, of concerns or criticisms, that the NAS [00:21:00] report brought out and, you know, I think one of our first questions that we need to ask is, are they right? And 

Of just kinda stonewalling. But-- And so one of them was a, a lack of scientific training. at the time, a lot of the bloodstain pattern analysts, the way that they were taught and the way that they were trained was, not necessarily in a science classroom. they were trained at, at local conferences or local workshops. BPA, starting in the 1980s, we had, Herb MacDonell. He is now-- he's called the father of BPA, but he's not.

He, he was the one who kinda popularized it in the 

Angela: Mm-hmm. 

Jeremy: BPA was 

Angela: it maybe?

Jeremy: in the United... Modernized it, yes, for sure, brought it to the forefront, but we had, we had BPA that was being used even in courtrooms in the United States long before, Herbert did his work. But he was-- he would go around the country doing these forty-hour basic courses to kinda introduce people to the concepts of [00:22:00] bloodstain pattern analysis, do some experiments, connect the, the, the, the features that we would see at blood stains scenes with different mechanisms. and he would do these forty-hour courses, and those have kind of become like a foundational piece within the community, where, it, it's almost like you have to take a forty-hour course to, to get into this discipline. And so we had a lot of people who would take a forty-hour course, that may be all the training that they did.

And they, they might do some in-house experiments, they might take an advanced course. and many of the, the, the only formal training that they had was limited to eighty, forty to hundred twenty hours, which in the scope of things, in, in the broader forensic science, is not really a lot of training. three weeks of training is, is really very little. So, and, and many of those people who, who took these courses didn't have a science background. now there's nothing entirely wrong with [00:23:00] that, but they were coming at it from a different perspective. They were coming at it from an investigator perspective or a detective perspective. who are bench scientists often come at the, the, the scene from a, from a different perspective. And so we saw that there was a, an, an education problem, an education gap, especially when we were trying to understand how concepts of fluid dynamics and 

Angela: Mm-hmm.

Jeremy: and, and anatomy and chemistry played into our discipline. not having a strong science background, makes it a bit challenging to get up to 

Angela: Угу

Jeremy: So that was one of their criticisms was not having a strong science background, in BP in, for those who are doing, bloodstain pattern analysis 

One of the things that we did to address that is we came up with, a, a training standard. SWGSTAIN had a training standard. It recommended a science degree, but it did not [00:24:00] require it. when, OSAC picked up the, the, that standard, it, it said, "Okay, you really need to have a science degree.

We're gonna give you four years, and then once this standard comes up for revision, then we're gonna make it a requirement." And that standard has now been-- gone through its second revision, it now does, require a four-year degree with, with science as part of that four-year degree. and I think that's a, a, a step in the right direction. In addition to that, that training standard really lays out a lot of concepts, that the, the training needs to go through and, and there's a lot of science in that. So th-that standard really is a step in the right direction 

Angela: Mm-hmm. So it, it requires science as a part of their degree, but it doesn't have to be a science degree itself? My understanding? Okay

Jeremy: a lot of... [00:25:00] Yeah, that's correct. There was a lot of discussion about that. And so I think what some of the educators, those who did training, they said, "Don't get hung up on the degree because we have seen a lot of people who are good analysts that don't have a science degree." So make sure they have a science in their background, but it doesn't have to be a science degree because there are some people who have a science degree that may not necessarily make the best of analysts 

Angela: I think we could say that's true for many different forensic disciplines. 

Jeremy: we 

Angela: The training standards Swgstain started it, OSAC worked on it some more. Like you said, we've, we've gone through additional revisions. We've changed just the underlying educational requirements. Has there been any, any more work on the training requirements themselves outside of your degree?[00:26:00] 

I mean, do they, do they outline more what the elements of each level of training needs to be?

Jeremy: Yes. So, the, the, the training, standard now has a lot of different things that are part of it. it deals with u-understanding the concepts of blood and, and human anatomy, where veins are at, where arteries are at, because that can kind of come into play. We deal with concepts of mathematics and trigonometry.

one of the, the techniques that we use in BPA is determining the three-dimensional location of an event, and the way that you do that is you look at the features of, circular to elliptical stains, you apply some trigonomic, approaches to, to those, those stains and some other measurements, can pull out what we call the area of origin, which is the location of three-dimensional space. we, we've talked about those concepts. There has been a lot of emphasis on [00:27:00] aspects of physics and fluid dynamics, which I'd never covered in my basic. So it, it talks about, surface tension and, viscosity. it talks about Newtonian fluids and non-Newtonian fluids. we deal with acceleration and mass and force and a lot of concepts that we just didn't discuss. understanding those now really helps us understand what blood in flight is going to do, and it really helps us understand, the reasons or the why behind the features that we see in bloodstains 

Angela: Mm-hmm. And so these are things that,those who didn't have a scientific background wouldn't have had any exposure to a lot of these concepts. You know, most science degrees require multiple calculus courses, multiple physics, and depending on your degree plan, you know, anatomy and physiology.

Not necessarily human anatomy and physiology, though. That would depend on what somebody was [00:28:00] studying. but all of those are really important. Now, how often we actually end up, in a practical sense, applying, the trigonometry that we, we learn to scenes for determining angle of impact and convergence and origin is a different discussion than us needing to be trained in how to use it and understanding, how fluid dynamics and viscosity and where is that blood drop actually breaking off, when the force is applied to it is, is different than what we actually end up doing in practice.

I mean, I, I occasionally calculate angles of impact when it seems pertinent to a particular question, but the majority of the time, the documentation is either insufficient or there's no information to be gained by going through the process of determining an area of origin, and events are dynamic, right?

So, you know, how much information are we able to-- how much of the training is actually do we [00:29:00] use on a regular basis in casework is a different discussion than the need for the basic training, I guess is what I'm trying to say.

Jeremy: Yeah, and that's, that's a good point because there's been a lot of research on angle of impact and area of convergence and area of origin. a lot of published research, some training manuals spend like a, a half of their training manual is on that concept. I have, over the course of 20 years, have determined area of origin four times.

So it is, it is heavily studied, but it's not utilized very well. And, and I'm not the only one who d- does that. There's a paper that came out, about six years ago where they, they re- they looked over and evaluated, actual bloodstain reports, and they wanted to see how often, different pattern types were reported out.

And what they found is that impact pattern was only reported in [00:30:00] 22% of, of those reports. So it's a heavily studied pattern, but it is simply just not reported out very often 

Angela: Right. Yeah, I think most of the time when we look at bloodstains and we look at the overall direction of, of travel that they were going, we might say the blood source was close to the floor or, you know, in about this area. But, l- as I tell my, my students, normally when people are in a fight or being stabbed, they're not motionless.

There's a lot of... People are moving around. It's not a static event. It's more like, think more like action movie, people are moving around constantly. So, 

Jeremy: That's true 

Angela: yeah, so we, we've got-- so we've, we've improved our training, better, better requirements that are, they're more spelled out than they were in the past.

So we're on, we're on the path to addressing some of the concerns in the NAS report from 2009. What are [00:31:00] your thoughts about their opinions for, their criticism about things being based on weakly tested methods? do you think there's been some improvement in that aspect as well?

Jeremy: Yes, I think there's been some improvement, and I think that that's,a legitimate, a legitimate point to bring up. And so if-- let's look at, let's look at fingerprints and, and they have a standard method. They have ACE-V. And, and that's the method if you were to ask anybody, who is a fingerprint examiner, you know, what's your method?

They'd say the ACE-V and describe the process, and they could describe the process. if you ask a drug chemist, what is the primary method that you use? most of them are going to use, gas chromatography, mass spectrometry. If you ask a bloodstain pattern analyst, what is your method? you're generally not going to get the same answer.

You may say, "Well, I use the size, shape, distribution, and appearance of the bloodstains [00:32:00] as well as my training and experience, 

conclusions." Well, o-once we say that our method is our training and experience, we no longer have a valid method. We, we no longer have something that is reliable because what that means is my training and experience is different than yours and is different than everybody else's.

So that means that every single analyst is using a different method and that's not where we need to be. We need to be somewhere where everyone is using the same process, and the same criteria. So we're, we're getting better at that, but we're still not quite there. there's, there-- And we, we've got a couple of papers that have come out where people were asked, "Well, what is your method?

what's the method that you use?" And the fact that we may have, you know, ten to fifteen different answers is, is, is pointing that, you know, we need to kinda shore this up a little bit. some of [00:33:00] those, some of those processes are better than others, and we just need to figure out which process is better than others. And there's some really good work that's being done by some researchers to start evaluating which processes are, are, are the better processes that research, more.

We have a method at my lab. We call it DCAP. It is documentation, classification, analysis, and peer review. And then each one of those has different steps. the documentation is looking at, what, what are the patterns? What are the distinct patterns? And then looking at the features of those patterns, their size, their shape, distribution, appearance, and location. And with each-- and within each one of those, we, we kind of split those out even more. Like distribution, for example, not just the arrangement of stains within a pattern, it is the arrangement of features within that pattern. just because you have a radiating [00:34:00] distribution, it doesn't mean that the features are always gonna be the same. Some radiating distributions, the smaller stains are close-closer to the convergence, and the larger stains are further away. In others, it's the larger stains that are closer, and the smaller stains are further away. those trends and features are also part of the distribution. So that's the documentation side of things. The, the classification is then linking those features a, a mechanism of deposition, and the process that we use is an exclusion-based process. Everything is an option, so 

seventeen different pattern types, and we start excluding those based on objective features or objective case information. And, have to document why we exclude something. We have to give the objective reason, and then what is left to be considered as, as a possibility. we can't exclude it, then it has to be reported. so that's the classification. The [00:35:00] analysis is kind of the reconstruction side of things.

This is where we start pulling additional reports. We start pulling,DNA reports, latent print reports, crime scene reports, medical reports to give us, the, the meaning behind the bloodstains. What do they mean? Where were people at? Where were they standing? How did they move? Can we determine sequences? Can we determine time? so that is the analysis side. And then the last step, peer review, it seems a bit funny to put peer review as part of your method, but for me, that's one of the most important parts because science is built on falsification and the ability to, to falsify. And the peer review for me is the falsification step. my peer reviewers, I ask them to not rubber-stamp it. I ask them to try and prove me wrong. So that, that is the, the fourth and, and in many ways the, one of the most critical steps of our method 

Angela: Well, and I would say that the method that you've designed is an, because of [00:36:00] h- the, the order of the process that you're using, you know, for the analysis part, you're not, you're not touching anything other than the documentation that you've used in the classification until you're ready to have that information given to you.

So this is, this is what, in the literature is the linear sequential unmasking process. So you start with the data, so it's a data-driven process and not a context-driven process that could lead to confirmation bias.

Jeremy: That's absolutely true. When I go into a scene, I read the story of the bloodstains. 

Angela: Mm-hmm. 

Jeremy: bloodstains tell a story, and I don't want anyone to tell that story for them. So I, I don't get any of that other contextual information. I don't get, officers' theories, investigators' theories.

I don't get statements by witnesses. I don't get statements by the, you know, the, the accused if the person survived. I don't get statements by the victim when I'm doing my classification. I just want the bloodstains to tell [00:37:00] their own story. 

Angela: Yeah. so I, that's another thing that I think is a unique, not 100% unique just to BPA. It's definitely something that's just in general something that crime scene investigators have to worry about because they're attending a scene. A lot of times there are still individuals at the location that, you know, witnesses, sometimes the suspects, the complainants, they're all present at the scene.

Th- sometimes they're more chaotic than other times, and a lot of times, I mean, you still have to get a little bit of a scene briefing, but it's, it's hard to tell them, "Stop. I, I don't want to know your theory," without, without being rude.

Jeremy: Yeah. Yeah, my, my team, they, they, they know that I don't wanna know anything. So, it, it's, it's humorous. Once I walk into a scene, they need to know stuff as the crime scene investigators. They need to know 

[00:38:00] Information to help guide them with, with their scene processing. But they know...

It, it's, it's funny. As soon as I walk in, I'll, I'll hear people say, "All right, be quiet, Jeremy's here." So it's, 

Angela: That's good. Actually, that's, that's probably a benefit of working for a single law enforcement agency. I know other, other groups, like when I was working for the, the state lab, we would be called out to all sorts of different jurisdictions by different, you know, because different law enforcement agencies requested assistance.

and so it, it's more difficult to have everybody trained, and they know, "Oh, they're here. Don't, don't talk to them." but I will say at that time, linear, sequential, and masking, expanded hadn't really, hadn't really been introduced 'cause that was, that was a while ago now.

Jeremy: Yes, it was. 

Angela: So, okay. Now, when we're talking about classification, I think that's another issue very much [00:39:00] related to, whether or not people had complete or thorough enough training and the way that we classify stains. Like, we have this standard list of terminology that was originally developed by SWGSTAIN, and that seems to have been-- It was largely adopted, by the OSAC, committee.

Jeremy: Mm-hmm. 

Angela: There have been some recent publications, like a very excellent paper that reviewed all the different, or at least the majority of the different classification methods that are out there. and they are different, and then we also have our prescribed terminology that we're supposed to use that doesn't necessarily fit with the methodology that you've just described that, that you employ at your laboratory.

So I would say that classification standard-standardization of terminology and language [00:40:00] is important, but are we all speaking the same language?

Jeremy: We're getting better at speaking the same language, but we, we still have some, we still have some, some old terms and old phrases that are popping up even in, in published papers today. So, the, the most classic example that I think I can give is high, medium, and low velocity impact spatter. Those three categories were created by Herb MacDonell, they were intended to describe the velocity, not of the droplets as they move through the air, but the, the velocity of the object that created this impact spatter. And, and, and what we're finding or what we have found over the years is those, those phrases at a minimum are confusing. they are, are-- It is likely that they are not rooted really in [00:41:00] any strong scientific principles and, and they are also, completely misleading in, in situations. so if someone says high velocity impact spatter, they, they will immediately-- most people will immediately jump to gunshot, that that means that it's a gunshot. And, and that is-- that's incorrect because I can create a, a cough or a sneeze, is a, a completely different mechanism, but it has the same mist-like features that you might see with a back spatter or forward spatter. you would, you would-- If you're calling it, based on just the size of the stains, it would fit in that, that range of high velocity impact spatter.

Well, people would say, "Well, this is a gunshot." and it's, it's misleading and it's incorrect. in two thousand and nine, when we came up with the SWGSTAIN terminology list, we 

that. We said, "We're, we're-- It, it's not a good concept. It's, it's inaccurate." So we [00:42:00] just called it impact spatter. unfortunately, if you read papers today, there are still papers that talk about high, medium, and low velocity impact spatter. And,we're getting better, but I, I still wish we could just kinda get rid of those terms that, that the broader community has abandoned and make sure that we're all speaking the same language. 

Angela: So what about the the hand- the handbook of bloodstain pattern analysis talks about it. m- the, the bloodstain group that I used to be with, we had, we had our own version of it, and it's a, a taxonomic 

Jeremy: Mm-hmm। 

Angela: classification scheme or a, a tree so we can see how things are, are related.

You know, spatter versus non-spatter. They, they're on different trees. 

Jeremy: Mm-hmm. 

Angela: so can you talk a little bit about that? And then maybe we should start broaching the subject of porous substrates versus non-porous str- substrates and, and how the taxonomy might be a little altered.

Jeremy: [00:43:00] Yeah. that's a, that's a great, a great, point. So you can define the terms, which is what the terminology list does, but then when you're trying to group patterns, that's when you get into the concept of taxonomy. And, there are two primary ways to, to group the patterns. One is to base them on mechanisms, like mechanisms are grouped together, or you can group them based on features. the historical way has been to group them based on mechanisms because it's easier to teach. so, Paul Kish, Stuart James, and Paulette Sutton, in their book, they have a, a taxonomy tree that has three different branches. passive stains, spatter stains, and altered.

stains, and then they, then they break down the different patterns that are within each of those three, three branches. a great way [00:44:00] of teaching BPA if you wanted to kind of say, "Okay, we're gonna talk about spatter mechanisms. Here are the different spatter mechanisms." But the, the problem is that it, it doesn't really work real well in, in casework. So if you take this taxonomy tree and you're trying to say, "Okay, I've got spatter, but which spatter do I have?" That tree doesn't give 

any guidance at all. Everything is grouped together in one branch. So what happened, around 2009 is Philippe Espéranca from France, he, he has a background in biology, and he was looking at the biological way of classification based on features and he said, "Well, let's just do the same thing with, with bloodstains." So he created a classification tree that instead of being driven by grouping things, for mechanisms, they were grouped by features. And, the purpose of that was to be able to-- so you could use it in casework. [00:45:00] So his classification tree, came out around 2009. Bevel and Gardner, published something very similar to that in, in the, I think the third edition of their book. And we've had other, other similar feature-based classifications that have come out since then. OSAC published a, a process map that is a feature-based, decision map for, for bloodstains. and then the book that you mentioned, "The Handbook of Bloodstain Pattern Analysis," it has a chapter that also, publishes some, decision maps that are feature-based. Those are much more suited for using in casework, when you use a feature-based classification tree than using a mechanistic-based classification tree. 

Angela: Right. It's, it's what do I s- what do you see? Right? 

Jeremy: Yes. 

Angela: Right. Does document our observations, so most people who go through science courses in general, you know, the lab courses, that's one [00:46:00] of the things that you, you learn to do, especially if you're taking a biology class. so I di- I didn't know that the feature-based stuff was sort of started by, by a biologist, looking at, looking at it from that perspective.

Jeremy: right. 

Angela: Okay. 

Jeremy: Yeah 

Angela: Well, I was just gonna cheerlead the biologists 'cause, you know, I am one. 

Jeremy: Yeah. Yeah. 

Angela: so yeah one of the other things too is I've been doing this long enough where I was like most other people, you know, you're, you're trained with the mechanisms, like learning how these patterns are formed, the forces that are involved in those, doing our trigonometry, te- teaching people in the training class how to use a scientific calculator, that, that kind of thing.

but I, I definitely, I, I would say I'm, I'm certainly much more a fan of the features. It feels, it feels right to go through and document what do I see, what do I observe, and especially if you've [00:47:00] got really good scene documentation, where with proper metric scales overall, mid-range close-up, you really understand the locations of the patterns and the bloodstains within the scene.

You've got a proper metric ruler next to it, which I learned that I take that for granted on many scenes or case reviews that, that I've done, is like, "Well, I could tell you something, but there's no scale, so I can guess on the size of the bloodstain based on the light switch on the wall, but I'm going to be very limited in what I can say because we're, w- we don't have the documentation that best practice," I would say.

Jeremy: That's right 

Angela: Yeah. okay. So, so what do you think the future of future approaches for classification is going to be? Do you think it's trending more towards the OSAC map, as, as one catalyst, the, the [00:48:00] handbook, and also, the Bevel and Gardner, book, talking more about a feature-based classification method?

Do you see that as what the, what the, the discipline is trending towards rather than the mechanistic approach, or is it still up for debate?

Jeremy: I don't think it's really up for debate. I think that what we see in the published papers and, and within the discussions that I'm having with some of my colleagues, that we are-- is a, a lot of momentum moving towards the feature-based approach. if you, if you look at some of the published papers, especially with those that are l- trying to incorporate artificial intelligence and 

Angela: Mm-hmm

Jeremy: into classification, is only based on, on features. some of those approaches, you define the features for the algorithms, and, in, in these deep learning models the algorithms are finding their own features for classification. But all of these are feature-based approaches rather than [00:49:00] mechanistic-based approaches. even, even in our own discussions, in OSAC and ASB that I've, I've helped out on recently, we are trying to move to- more towards, all right, what are the features that are critical and, and what do they mean?

What is a s- what is a scallop? What is a spine? What is feathering? What are striations? To kinda define those to, to help shore up this, this idea of documenting what you see, and so that we're all trying-- kinda coming up with the same language, when describing features 

Angela: Yeah. And how do, how do we account for Let me see if I'm trying, I'm trying to figure out what question I'm trying to ask. So I'm circling back a little bit on the difference between 

Jeremy: Mm-hmm 

Angela: porous versus non-porous surfaces. There is a com- very big difference in the features that are discernible when you have bloodstains on a tile floor [00:50:00] versus on a carpet versus, you know, the, the couch, the bedding, people's clothing.

It's very different what you see and the features that you can see. What are the issues that we have around classification as regards stains on these two different types of broad categories of, of surfaces?

Jeremy: So if we, if we think about rigid non-porous surfaces, walls and, painted walls, floors, tile, concrete, those mimic w-what we typically do in training if we put bloodstains on cardboard or we put it on paper. we, we know h-what blood-- how blood interacts with those surfaces pretty well. We know that it, it's gonna, it's gonna spread, it's gonna splash, it's gonna create satellite stains. But once we get into absorbent, target surfaces like fabrics, the rules completely change. [00:51:00] And that's one of, the things that we learned,kind of some national cases in the past, that we didn't really understand how liquid blood interacted with absorbent surfaces very well. And we were trying to use the rules for bloodstains on painted walls to help us interpret bloodstains on, on clothing, the rules don't apply. it is a 

Angela: Mm-hmm.

Jeremy: different set of rules. the, the features that we use to classify patterns on clothing are going to be different. It's gonna be a different set of criteria than what we're going to use to classify patterns on, on painted walls and floors 

Angela: Yeah, I think there's been, there's been quite a bit of research both in the behavior of blood, you know, the, the, the fluid dynamics of the fluid it- the dynamics of the fluid itself, and understanding how it responds to different physical forces and different [00:52:00] environments. But also, there, there's research into textiles as well, and that gives us a baseline information.

A lot of it's been done on, 100% cotton that's knit, and it's stretched in an embroidery hoop, and it's very controlled, which is excellent to give us some understanding, to develop formulas that can describe the process of wicking and the movement of the blood through the fibers. But are we ever gonna know everything about the shirt or the shorts that a person was wearing when they were in the presence of the blood-shedding events?

you know, how did they wash it? Because treatments change the behavior of the fabrics as well, right?

Jeremy: Yes, they do. I think what we're finding with-- as, as this published research comes out is that there are a lot of things that [00:53:00] affect the, the final features of bloodstains that we didn't know about beforehand. 

Angela: Mm-hmm.

Jeremy: And, and some of those things we will never know what those-- what is present or what is not present. our uncertainty when it comes to, to classification goes way up, because of the nature of, of that textile. for me, when, when I think about the patterns that I have classified on clothing, I think it's like four. It's bloodstain, saturation, transfer, spatter. that's it, are those primary four. and, and bloodstain simply means I don't know, I don't know how it got there. I, I can't tell you if it is-- if it's a, a transfer. I can't tell you if, if it's, if it's a drip stain. so I'll just call it a bloodstain. And then, there's been a lot of published research on the difference between a light transfer and spatter. And, and even when it comes to spatter-producing mechanisms, there are [00:54:00] all kinds of spatter-producing mechanisms, but the, the absorbent nature of textiles results in a significant loss in information and a significant loss in information that is what we would use to differentiate between the different, spatter-producing mechanisms. So that's why I just end up at spatter, most of the time

Angela: So some of these cases that I mentioned at the beginning, a lot of the the controversy was surrounding classification and interpretation of bloodstains on textiles. So what are your thoughts around that? Is it... M- my, my inclination is to, you know, just give it a broad category because there are so many unknowns I can only go so far. It's the uncertainty is, is large. So

Jeremy: Yeah. [00:55:00] So

the way that I approach it, let's look at spatter stains. on, on painted surfaces, to call something a spatter stain is pretty straightforward. Is it circular, elliptical, well-defined edge? We, we kinda know what that looks like. But on, on clothing, what we have found with some of these cases is a light transfer where something barely touches a textile can give you a circular to elliptical stain that's just a couple millimeters wide. 

Angela: Mm-hmm

Jeremy: we have very defined criteria that have to be met. In order for us to call spatter stains, we have to have three criteria that have to be met. We have to have the right size and shape, so it has to be circular to elliptical. it has to penetrate the construction of the fabric, so it can't just be on the surface of, of the fabric.

It has to penetrate into the weave or penetrate into the twist of the yarn. then the third criteria is that it has to be spread across the garment [00:56:00] unless it is in an obviously linear distribution. So um, the, the, broad distribution, is if I've got, you know, let's say I've got ten stains that are in an area that are five centimeters by five centimeters, that's not a broad distribution.

When you think of most spatter-producing mechanisms, the blood's gonna go flying everywhere, so it's gonna cover a large area of a garment. so if I've just got spatter-- these circular to elliptical stains that are in a very small area of a garment, that should be a red flag that, that I may not necessarily be dealing with the spatter mechanism. and in those situations, I may back off and just call them bloodstains. now if they are in an obvious line, like for a cast-off or a projected pattern, that is the one exception that we have then. So we have very specific criteria to-- in order for us to call something spatter stains on textiles

Angela: So [00:57:00] the, the, the ability of the blood to penetrate into the fabric, can that be altered by the technical nature of the fabric or the treatment of the fabric as well

Jeremy: Yes, it can. you can affect it both ways. and some people will say, "Well, let's look at the, the nature of the textile." Polyester is hydrophobic and, and cotton is hydrophilic, water-loving or water-hating. But there are chemical treatments that we can put on that make cotton act like polyester or will make polyester act like cotton. yeah, we can make the... We can make a textile be high wicking so that we just lightly touch it and it, it draws the blood into the interior of the, of the textile. the best example of that are high-performance, T-shirts, like that are, your high-wicking T-shirts. They are designed that any time a liquid [00:58:00] touches it, it sucks that blood in and, and, and spreads it out. those are a real challenge because we may not be able to tell the difference. we can also have a textile that is, is treated with like a stain repellent water-resistant that the blood just doesn't penetrate in. It beads up on the surface. we're learning a lot more about textiles than what we, we knew before 

Angela: Right. now as far as determining when it, when you are assessing, let's say we just have a, have a regular fabric, no special treatments, no fancy technical stuff to it. So we're trying to assess did the blood penetrate the fabric? Is this something you should be doing with the naked eye, or should you be using some type of magnification to assist you with this determination?

Jeremy: I don't see how you can do it without magnification. So we have, stereoscopes that we use, and we can go up to 60X, and [00:59:00] that allows us to, to see the blood interact with the different yarns and threads. we even have some microscopes that go up to 200X. and I really think that when it comes to spatter versus transfer on clothing,y- some type of magnification, whether a, a, a lighted magnifier, or, or a stereo microscope is, is almost essential to do this work if you, if you want to be able to have the objective evidence to call something a spatter stain. 

Angela: Okay. So I would, I would think that by and large most experts, that, you know, have gone through proper training, they've, they, they have good methods that they can practice.

When it comes to non-porous substances or substrates, there's probably not a lot of disagreement. Now, when we have highly textured surfaces, it, it might be a little [01:00:00] bit different 'cause, you know, concrete and asphalt make, make it a little hard to see features, sometimes. But you know, that, that smooth tile floor, the painted door, we're n- we're typically not disagreeing that much in those cases.

It does seem like most of the time, the, the disagreement does come w- on, we do see that with clothing. And I know one of the things that I've noticed, Now I'm, I, I teach undergraduate students at this point I do a special problems in bloodstain pattern analysis, and the focus of that , course is understanding the challenges and limitations of BPA because, you know, they do the basic experiments before that class.

They've done some where they, they drop the blood, and they see how cast-off is created, the mechanistic aspects of it. And they have the Dexter television show as their guide- guidance document, for, ooh, this is what BPA is. And I was like, not really. if you're in this field, if you're in this field 'cause you were watching CSI and NCIS [01:01:00] and Dexter, you're going to be disappointed in the amount of paperwork you're doing.

Jeremy: Yeah. 

Angela: but one of the things that I do in, in that class is try to drill into them what do you see first. Because they immediately look at what they think is a pattern, and they're like, "Oh, it's this. Oh, it's this. This person stabbed this person." You're like, "No, no, no, no, no, no. You, you have jumped way ahead of where you need to in the process.

Let's start with observations. You have to make your observations first." and then the other thing that I noticed that they tend to do when we start looking at clothing, 'cause w- I make them come up with their own crime scene, and they have to recreate the bloodstains, and then they switch teams, and they each investigate each other's stuff, including wearing clothing over Tyvek suits.

You know, safety first. and what I see is on the clothing, they tend to, and I've seen this in the laboratory as well, people examine the clothing flat. They [01:02:00] document the clothing flat. And unless you're on a really intense GLP-I, most people are not flat 

Jeremy: Mm-hmm. 

Angela: So, 

Jeremy: We, we are not Flat Stanleys, that's for s- 

Angela: yeah. So that's, that's one of the things that I've observed a, a few times, is people forget you have to, you need to envision a garment as if it was worn, and remember that it's not sitting on the person in a perfect arraignment like it would be on a mannequin in the s- in the store, right? Somebody's moving, especially if they're being punched and stabbed and right?

Or if they're punching and stabbing someone.

Jeremy: Mm-hmm. 

Angela: So I guess I'm just saying comment on complicating factors

Jeremy: Yeah. So I'm really glad that you brought up the, the, how we typically analyze clothing. Pretty much everyone does it the same. You'll open up your item, lay it flat, photograph it, flip it over, lay it flat, perhaps turn the pockets inside out, perhaps turn it around. [01:03:00] But most of our exams are, are in documentation are with the clothing flat. but you're right, we're not flat, we're round. We've got curves. And where something when you look at it flat maybe l- may look like it's on the front, when you put it on, it's actually on the side. 

Angela: Mm-hmm.

Jeremy: one of, one of the things that we have in our procedures is we call it three-dimensional analysis, and it's exactly how you des- what you des- have your students do. we-- I will find someone to, to model the clothing. Now, there's a couple of critical things. the first thing is it's done after the DNA is collected. So

Angela: a DNA person, thank you.

Jeremy: So I make sure that all the DNA is collected, because, I, I, I wanna, I wanna make sure that that's preserved. So that, that has to be done first, and then the next thing is I want to find the, the physical dimensions of the person who we think was wearing the clothing. I wanna know how tall they were. I wanna know their, their [01:04:00] body type and their stature. then I, I wanna find someone who is about that same body type and stature and height and, because I wanna see what the clothing looks like.

And tend to have, especially if it's worn, they tend to have a memory to them. They're gonna 

Angela: Угу.

Jeremy: in the same place. So I'm gonna have that person put the clothing on, after they've got a Tyvek suit on, and then we're gonna take some various photos. And,I will, have them move their arms in certain ways.

I'll have them maybe in a seated position, a squatted position, laying down, trying to see how, as you move the body around, what does that do to the bloodstains? if you are in a standing position, the bloodstains on the legs may present themselves in one way, but once you sit down and that garment changes, that now changes the orientation of those bloodstains, and they look different. And it allows me to see what parts of the garment are forward-facing and what [01:05:00] parts of the garment are backward-facing. so three-dimensional analysis has been very eye-opening, for some cases, of mine in the past 

Angela: That's one of the things that, you know, I've always wanted a mannequin in the lab, right? Preferably one of the adjustable ones 'cause they make dress forms where you can dial up the waist and all that. But, I, I don't, I don't, I don't know that I could get the budget approved for, like, a whole series of those.

So it probably is better for-- to find an em- a lab employee and put it under other duties as assigned. Please be our bloodstain model

Jeremy: Yeah. I've never had anyone turn me down. They think it's kind of fun. It's different than, than, than looking at evidence to, to say, "All right, I need you to put the evidence on and then, and, and be a model."

Angela: Yeah. Yeah. But I, I, it's really critical that you do it after the, the DNA has been collected from it. So, but it's also good that it sounds like you're s- keeping the process clean by making sure people are wearing their Tyvek suits [01:06:00] and, and, and it's still in a controlled environment 'cause you never know what you end up having to go back and test, you know, f- the case goes cold or if it is, does come up as a post-conviction thing.

So, okay. now, we, we, we've hit a lot of subjects, talked about a lot of things. Is there, is there a question that you wish I had asked you that I have not yet asked you?

Jeremy: Um Well, I, one of the-- there's-- one of the chief statements that's made about BPA is that it's junk science. And, and obviously I disagree with that. but I think the first thing that we need to discuss is what, you know, what do we mean by junk science? And, i-if we've got criticisms about, you know, a specific conclusion or a specific process, let's talk about, about those conclusions or the processes. some processes are obviously much better than others. and, [01:07:00] and I, I think that some analysts, may not have given a lot of thought to their process. they, they'll just go in, and as you mentioned, you know, your students immediately want to jump to what made it. Look at a pattern and what made it. It was this, it was this. And, 

and you-- what I've seen when I teach even just documentation classes, even adults do the same thing, and investigators. They'll, they'll walk up to some patterns they won't even document. They'll say, "Well, I think you did this." Like, well, that's, that's not the point of the exercise. And it just shows me kind of a little bit of a sneak peek into human nature, that we're all... I think we are caught up in trying to answer the what did it, and we're getting ahead of ourselves. So we've gotta create a process that is very thorough and methodical kind of force ourselves to look at the features and, and not get caught up at the beginning of what it is, to do a [01:08:00] bottom-up approach of thinking rather than top-down. And, if we do that, I think we're gonna really start silencing these critics, that are saying that we, that we are a junk science. if we can, can show that we really have a, a, a, a methodical, a well-thought, scientifically valid process that appreciates the concept of uncertainty, we are comfortable saying, "I don't know. I, I just don't know what, what happened here." 

Angela: Yeah I think that is a perfect statement to end, end our discussion on. I think that's a great take-home, unless you wanted to add another one. You have any other pearls of wisdom?

Jeremy: Oh, I don't know if that's a pearl of wisdom. It's just something that, that I've learned over the years is that, you know, when, when, when we take the stand as experts, we have a powerful presence on the stand. [01:09:00] and you can talk with attorneys and they'll tell you that, that the, the jurors, when a forensic scientist gets on the stand, they, they pay attention.

And then when someone gets on the stand that can reconstruct a scene or that's their job, they really pay attention. And our testimony is powerful testimony. And, and, and we need to check our egos and realize that, that there is a lot of responsibility that comes with that. And, and to make sure that the words that we use are, are carefully thought, they're carefully constructed, they're rooted on objective information, they're rooted in science, and, That, that they're measured. and, and we need to, to not try and be the all-star witness, the one that slams the door for the case of either side that, that we're testifying for. My allegiance is to the science. My allegiance isn't to the case. And, and I hope that all [01:10:00] scientists take that approach that I'm here to defend the science and not necessarily make a case. If my science and my conclusions help out the investigation, that's fine. If they don't help out the investigation, that's fine as well. I, I need to be objective in what I say and, and be, be comfortable to, to say I don't know. 

Angela: Okay. I thought you said you didn't have any more pearls of 

Jeremy: Oh, this is just an old guy who's blabbering is all it is. 

Angela: So, I, I, I completely agree with you, to be honest, 'cause, you know, you can tell when you walk into the courtroom, the demeanor of the jury changes. and I've seen it when I've been observing someone else's testimony. it's the, it's the same thing. They, they, they, they take notice, and what you, what you say has a great deal more weight than, than fact witnesses, will have.

And what you say can mean the difference between a, the difference between someone [01:11:00] who's innocent being convicted and possibly facing the death penalty in certain, in certain states. So it's not just someone can end up locked up behind bars. it could mean that their, their life is going to be taken away, and that's a tremendous responsibility, and that's why it's so important that we are very transparent about what the limitations of any scientific testimony is.

W- you know, bloodstain pattern analysis or anything else. And, you know, in the NAS report, even though it was quite critical of BPA, it didn't say that it was a junk science. It just said we need to be more mindful of certain, certain aspects. It, it, that it does have a place in forensic science. We just need more research.

We need, we need to, to, to work on our scientific foundation, which I, I would say the discipline has definitely been, been doing, doing their best to get there. Things move slowly quite often. But in the meantime, everybody is... well, I'm not gonna say [01:12:00] everybody. We're, we're trying to be, as you said, more measured with things.

Jeremy: Yes. Yes, that is true. 

Angela: Yeah. well, thank you very much for coming onto my little podcast corner of the, of the internet. I appreciate it. 

Jeremy: Mm-hmm. 

Angela: r- I've really enjoyed the conversation. Yeah. any other closing thoughts?

Jeremy: No, I really appreciate, the invite. I hope that, hope that my, my thoughts

or my opinions or insight has been helpful. but again, thank you for this opportunity. It 

Angela: Yeah. 

Jeremy: an honor. 

Angela: Thank you. And, I always say thank you for having a nerdy conversation with me. 

Jeremy: Mm-hmm. Yeah. 

Remember to join us November 18th, 2026, at the Gateway Center Ballroom at the University of North Texas for Bloodstain Pattern Analysis in the Courtroom: Lessons Learned from Wrongful Conviction Cases, Contested Forensic Testimony, and Evolving Forensic Standards. I hope to see you there. Remember, registration closes November 6th.

The registration link is in the show notes.