Junk Science – Bloodstains & Bite Marks

Episode Notes

Transcript

Michael Semanchik:

Science is always changing. As society advances forward, the things that used to be fantasy are now reality. Think of the advancements in the last 120 years. Winged flight in the sky, rockets to the moon, the internet, mobile broadband, driverless cars, and yes, Netflix 24 hours a day. Our modern world is really quite a marvel. One thing that remains constant is that things are constantly changing. What we understand to be true today may not be so in the very near future. The same can be said about our criminal justice system. It might disturb you that there are innocent people in prison right now serving life sentences because of scientific theories that were later disproven. You might be thinking, come on, there’s got to be a program out there that monitors these things and notifies the courts that a forensic science has been invalidated. Like a list of all the cases where a particular science was used. No. No, there’s not. My name is Michael Semanchik. I’m the executive director for the Innocence Center, and this is junk science, bloodstains and bite marks

Speaker 2:

Spent most of my life in prison chasing our dream. Call Justice, chasing our dream. Chasing a dream. Want somebody please want somebody please Free.

Michael Semanchik:

Junk science is a real challenge for criminal cases. That magic CSI moment that blows the case wide open is a myth. Murder cases in real life are way more complicated. There are nuanced degrees of evidence, reliability, oftentimes with arguing experts claiming their version of science is the truth. And to pile on juries will often have to sift through multiple layers of competing scientific theories and weigh them against each other. It’s not easy. It can take a long time. And once a decision is made, the courts are very reluctant to overturn it even when one piece of evidence is later found to be scientifically unreliable. And there are many examples of those unreliable scientific theories that have been debunked. In some instances, prosecutors no longer use them and in others they still use them, but with much less evidentiary weight sciences like bite mark matching and hair comparison analysis were once thought to be as reliable as fingerprints.

Today they are deemed far less reliable for identification, although still used occasionally as supporting evidence. Fire investigation methods and child autopsies have evolved a lot and are not being done in the same way because of past unreliability and yet other newer evidence forms like DNA and bloodstain pattern analysis have provided irrelevant information at times, and that’s what David Rudolf and I discussed together. You might remember him from the Staircase documentary on Netflix. David was Michael Peterson’s defense attorney during that famous murder trial. At the center of the prosecution’s forensics was bloodstain pattern analysis. If you were a regular watcher of Dexter, you’ll probably remember that bloodstain pattern analysis was Dexter specialty. For those of you that don’t know, bloodstain pattern analysis is the forensic discipline where an expert attempts to determine how blood ended up on a surface at a crime scene. To do that, experts will look at the amount of blood as well as its shape, distance, and size to make their calculations. Here’s David Rudolf and I talking about bloodstain pattern analysis and the difficulty his client had with it.

David Rudolf:

So it started back, I guess in the eighties or maybe late seventies eighties. There was a particular guy who was the father of bloodstained pattern analysis who was up in New York and he didn’t have any particular expertise in physics or any science that related to how blood spatters or what it does. But he decided he was going to start teaching people how to do it and he was very successful at teaching a lot of people how to interpret blood spatter. And I won’t say that there’s nothing scientific about bloodstained pattern analysis. There are certain things you can tell, you can tell, for example, velocity. You can tell if it’s very fine spatter, it was probably caused by a high velocity incident like a gunshot. If it’s much larger drops, then it’s probably either medium or low impact spatter. But the lines between high impact spatter and medium impact spatter and low impact spatter are a little bit cloudy. If you have really fine mist, you can pretty well guarantee it’s high impact. If you have really big drops, you can pretty much guarantee it’s low impact. And where in between, well, that’s where the science sort of breaks down and it becomes subjective

Michael Semanchik:

In addition to velocity. Bloodstain pattern analysis can give us some indication of direction and area of impact, but its accuracy is relatively limited as we’ll soon hear.

David Rudolf:

You can tell directionality by spatter, you can tell where the tail is, sort of like a sperm and tell that’s where it was headed towards the head. You can tell generally area of origin if you have enough spatter and you do it properly. There are actually algorithms and computer programs where if you feed in the angle of a particular blood spatter on the wall, which you can figure and you do enough of them, you can determine what’s called an area of origin, which generally speaking is about 12 by 18 inches. That’s the best you can do. So I’m not saying that blood spatter has no usefulness in a Courtroom, but its usefulness is very limited. Let’s take Dwayne Deaver and what he did. He’s the blood spatter expert in the staircase and I cross examined him for days and confronted him with all kinds of learned treatises. And I had Henry Lee come in and talk about blood spatter and Tim Poba who was his associate, and they impeached diva, but diva came in and he said that he could determine a point of origin.

Michael Semanchik:

For those not familiar impeaching, an expert witness is a regular part of criminal trials. Essentially, it is a process used to discredit an expert witness who is presenting evidence against your client. In this case, David brought his own experts, Henry Lee and Tim Palmach to present an opposing view different from Dwayne Deaver’s testimony. This happens frequently when forensic science is used in the Courtroom.

David Rudolf:

So he comes in and he does his thing and he testifies at trial that the points of impact from these spatters are 23 inches off the west wall and 16 inches up from the floor and it’s out in space. And he did that with three or four of those spatters. Now think about that for a second. Our theory is that she fell down the stairs and hit her head on a wall or a step or both. He’s saying, no, no, no. The spatter didn’t come from a wall or a stare or the floor. It came from out in space. And the only thing that could have caused that spatter to start 16 inches off the wall and eight inches up from the floor is an instrument of some sort. In this case, a blow poke.

Michael Semanchik:

So if you’re thinking what the heck is a blow poke, you’re not alone. A blow poke is an uncommon but useful tool for the fireplace. It’s a long thin hollow shaft with a barbed pointy end. It’s made out of metal for safe movement of wood in a fire and it’s hollow to allow air to be blown directly into the coals. Aside from its obvious value on date night, the blow poke turned out to be a critical piece of evidence in the Michael Peterson murder case because it initially lent credibility to the blood spatter evidence. But here’s more on that from David.

David Rudolf:

So it was absolutely critical evidence in the case. It was probably the most critical evidence. It was the thing that distinguished our theory from their theory.

Michael Semanchik:

So the jury hears him testify before you have an opportunity to cross. What do you think the jury’s thinking? Well,

David Rudolf:

I mean, he had exhibits, he had experiments he had done. He came across as this really well qualified person. And so obviously if you’re on the jury, and we all know this, all lawyers know this experts have extraordinary weight for the most part with jurors. And so I’m sitting there, I’m listening to all this and I know it’s wrong. I mean, he called something cast off when the two blood spatters were headed in opposite directions. It couldn’t be cast off. And I knew this and I’m sitting there listening and what I’m watching is the jury, he has a whole model there and he’s pointing where the areas of origin are. The jury then is obviously convinced that this must have been an instrument, the blow poke and who’s in the house, but Michael Peterson. So it was devastating testimony and as I said, I spent literally hours and hours cross-examining him about everything he did to no avail.

Michael Semanchik:

During the course of Michael Peterson’s trial, the prosecution’s bloodstain pattern expert Dwayne Deaver recorded video of him performing blood spatter experiments on mannequins to prove his conclusions. The visual component of these videos impressed the jury, but as we will soon hear, the premise of these experiments was all wrong. They were set up to reach a certain result as opposed to testing a hypothesis for its validity when carried out properly. The scientific method is designed to be critical of a hypothesis rather than serve to support it.

David Rudolf:

I don’t think it’s common to do experiments, although it probably should be if the experiments are done properly. He was doing experiments to prove his theory. The scientific method is you do experiments to try to disprove your theory. If you can’t disprove your theory, then you publish that and then you let other people see if they can disprove your theory. And if your theory survives all of that, then maybe, maybe, maybe it’s a valid theory. He didn’t do any of that. He did experiments designed to prove his theory, and so he set ’em up in a way that was designed to prove his point. If you will

Michael Semanchik:

Get the evidence to fit the case theory

David Rudolf:

Right? That’s exactly right. That’s exactly right. That’s junk science. That’s the definition of junk science, and it’s the definition of an expert abusing his power.

Michael Semanchik:

So that’s the danger of junk science. It can really sway a jury with captivating visuals. Most jurors want to do the right thing and they seek definitive answers. When a confident so-called expert gives a flawed but easy to understand presentation, it can be nearly impossible to steer the jury away from it. People like clear cut conclusions. The problem is that the truth can be much more complicated and nobody wants to hear that. Another great example of the visual power and junk science is bite mark evidence. Bite mark evidence has been used to identify assailants who left teeth marks on their victims. It was not a new science when it hit the zenith of its popularity in the criminal justice system. Despite non-consensus among experts, it’s somehow achieved wide-scale legitimacy. In the 1980s, that trend plus its use to prosecute fame serial killer Ted Bundy, made bite mark evidence into a household name. Judge Christopher Plourd presides over the superior court of Imperial County here in California. We discussed the sudden resurgence of bite mark evidence during that time.

Judge Christopher Plourd:

Well bite mark evidence has been around for 300 years. It started with the Salem witch trials and essentially it tries to identify a perpetrator, somebody that bites another person, and it tries to then get a model of the person’s teeth, the suspect, and compare the two and make a conclusion that a particular person bit somebody or something. So it was not too well used in the 1960s, 1970s. But in the 1980s there were a few cases where dentists who were doing dental identification work, meaning identifying deceased victims through their dental records, ventured into the bite mark comparison field. The most notorious case was a case out of Florida by the name of people versus Ted Bundy. It got national headlines. It was one of the first nationally televised trials and bite mark evidence figured very prominently in identifying Mr. Bundy. So all of a sudden bite marks in the mid 1980s become very popular.

And the next thing you know, bite mark cases are being filed and prosecuted all around the United States. It became a kind of a thing or a fad and bite mark experts would say. Some of them would say things like bite marks are better ways to identify people than fingerprints. It’s not 99%, it’s a hundred percent certain. And they would testify to these conclusions. And a lot of people started getting convicted in the 1980s and the 1990s by these experts that were telling juries that they were experienced and that they could tell that these teeth made these marks on this person or person’s.

Michael Semanchik:

As it turned out, bite mark evidence was not nearly as accurate as the experts claimed. Like so many junk sciences bite mark evidence has an air of truth. It’s true that dental records can be used to make identifications. The shape, size, and orientation of teeth plus dental histories can be unique to individuals from that perspective, there is validity to using bite marks to determine identity. Where bite mark science gets into trouble is surfaces. Not every surface is ideal for recording an accurate bite mark. Unlike impressions taken at your dentist’s office, which give accurate depictions of tooth structure and shape bite marks taken from malleable surfaces under chaotic conditions can leave distorted representations of what someone’s bite looks like. For example, if someone is bit during an attack, they might pull away ripping and distorting their skin in an effort to protect themselves. That distortion will also affect the bite mark that is left behind other surfaces like food can change shape as they age.

A bitten apple may have rotted or dried out a little before investigators catch up with it. As such, the bite mark shape left behind is likely to have changed. Judge Plourd was part of a pivotal case when DNA evidence came to the rescue of an innocent man who was convicted on bite mark evidence. Ray Cron was falsely convicted of the murder and kidnapping of Kim and Kona. In 1992. He received not only the death penalty, but the court decided to add another 21 years for good measure. Despite the court itself having doubts about the underlying evidence, Ray was convicted again during his appeal in 1996. That’s when Judge Plourd got involved. Here’s how bite mark evidence played out in that case.

Judge Christopher Plourd:

It had bite mark evidence. The expert said it was a certainty that Ray c Crone made the mark. The defense lawyer did not hire his own independent expert. He hired his local dentist who said he didn’t know much about it so he could not contradict this nationally recognized expert who testified against Mr. Cron. Mr. Cron had two experts testify against him in his first trial, and one of them was the local tologist who worked for a medical examiner. And he came to certain conclusions that led to his being indicted. And then they hired a nationally recognized expert who made a positive identification on multiple bite marks on the victim that led to Ray Crone’s original conviction and his sentence to death row.

Michael Semanchik:

How did you undo all of that in the retrial?

Judge Christopher Plourd:

So the case was when I was retained, I was retained essentially to do a post-conviction review of the evidence because the original lawyer didn’t do a whole lot. The case was on appeal. So I worked with the appellate lawyer on the appeal issues and started investigating all the things that should have been investigated initially. And I had four bite mark experts who disagreed with the prosecution experts. I did some DNA testing, I hired a blood spatter expert. I looked at all the fingerprints and some foot impressions that were at the scene were not consistent with Mr. Crone. All the physical evidence, nothing matched Ray Crone,

Michael Semanchik:

The influence of junk science can be very difficult to resist. For Ray Crohn’s case, there was no actual physical evidence placing him at the crime. The fingerprints did not match, the foot imprints did not match either. There was even a shoe left at the crime scene and it also did not belong to Ray. In short, there were multiple pieces of evidence pointing to someone else, but it was not enough. A second jury trusted the bite mark evidence and found Ray Crone guilty. Once again. It was not until DNA evidence pointed to a known offender in the area was the court able to see through this mistake? Unfortunately, it would cost Ray Cron 10 years of his life behind bars.

Judge Christopher Plourd:

All of it was eventually presented to a second jury and it really came down to the experts disagreeing and the jury convicted him again. And the way they did that was that they took the models of the teeth that were made from Mr. Crohn’s teeth and they took the impressions that were made of the bite mark by the expert and they said that they looked like they fit. And therefore the jury concluded notwithstanding that the experts all be in a disagreement that therefore Crow must have committed the murder. The case again went up on appeal and it was affirmed on appeal. And then we did some additional post-conviction, DNA testing. There was a new law that was passed in Arizona when the DNA commission started in the 1990s to allow people to get DNA testing done after their conviction. And we waited for a period of time so that the DNA data bank, which is known as CODIS, was up and running.

Michael Semanchik:

So just a quick note about codis. CODIS stands for the combined DNA index system. It’s a DNA tracking project done in conjunction with local, state, and federal law enforcement agencies. Basically, it’s a database of known DNA profiles and it’s used to identify genetic material found at crime scenes. The DNA profiles in the system come from known offenders and missing people. They also collect unknown samples from crime scenes in order to catch serial offenders. When a DNA sample is recovered, it’s sent to a lab to be examined for genetic markers. Those genetic markers are then shared with CODIS to see if there is a match. Law enforcement uses that information to help eliminate suspects or prove guilt. With all of that said, let’s get back to Judge Plourd telling us how they used CODIS to free Ray Cron

Judge Christopher Plourd:

Because we knew Mr. Cron was, we thought he was innocent, but eventually we did some post-conviction, DNA testing, and we had the Phoenix Crime Laboratory, who was very cooperative at the time, run it through the database, the FBI database of codis, a convicted offender database. And we got a hit. We got a hit to a person who was in prison, had gone to prison about 30 days after the murder of the victim in Theron case had lived about 600 yards away from the crime scene. And it was just a shot in the dark. The prosecution initially opposed and said this was just a fluke. But then they redrew blood sample of the alleged perpetrator that we had identified. We had somebody talk to the person in prison and he denied at first being there, knowing anything. And then finally when the DNA evidence was explained to him, he said, oh, he must have had an alcoholic blackout.

He remembers waking up with blood all over him, but he didn’t remember exactly what happened. But he did remember being in theBar. His fingerprints were subsequently identified. The unknown fingerprints turned out to be his. There were other stains that were identified to him, and we knew it was him because the profile that hit was on the victim’s tank top that she was wearing at the time she was attacked. And I had came to the conclusion that it appeared she was bitten through the tank top. So we tested the tank top to determine forensically whether there was any amylase, which is something that is in high concentration in saliva, and that’s what we did the DNA testing on and where we found the perpetrator’s DNA profile that ultimately matched, matched the database and then other blood and other things were also identified to the victim, including pubic hairs that were found on the victim.

So Mr. Cronin was exonerated and the person that was identified was eventually prosecuted and he was given a plea bargain of life in prison. So took years for all this to unfold, but I went to his sentencing actually as a point of closure for me because this case lasted eight years for me and I wanted to see the end result. And I remarked to a reporter at the time of sentencing after it was over, was the innocent guy gets the death penalty, but the perpetrator gets life in prison. I thought that was ironic, but that’s what happened.

Michael Semanchik:

Luckily for Ray Crown, there are people like Judge Plourd who won’t give up on the truth. That case was a real tipping point for bite mark evidence. After that, it would no longer carry the same weight. In recent years, there’s been a push to further de-emphasize the use of bite mark evidence in criminal prosecutions, but it’s still being used today. If there’s one thing we can extract from the bite mark era, it’s this. Once junk science gets entrenched, it becomes very difficult to discredit. This is especially true when the so-called experts are well-funded and supported by educational institutions. There is probably no better example of an entrenched junk science than Shaken baby syndrome. Where did it come from? How did so many experts get it wrong? Why did it have so much institutional support? And what can we learn from such a widespread misunderstanding of data? That’s what we’ll discuss next time when we continue our conversation about junk science. Thank you for listening. We hope you enjoyed this episode. Brought to you by the generous support of Clio, the legal operating system for client-centered law firms. Produced and written by Laurence Colletti Audio Engineering by Adam Lockwood. Special contribution of music and sound elements by real life exoneree William Michael Dillon. You can find his catalog of [email protected]. That’s framed D-I-L-L-O n.com. Until next time, I’m your host, Michael Semanchik, and you’ve been listening to For The Innocent here on Legal Talk Network.