This episode contains details of gun violence against children. Please take care where and when you listen. It's a summer day in June two thousand and seven. Christopher Vaughan and his thirty four year old wife, Kimberly, and their three children pile into their suv early in the morning. Abigail is twelve, Cassandra is eleven, and Blake is eight. The family is on their way to a water park from Oswego, Illinois, where they lived outside of Chicago. They were going to drive about three hours down to Springfield, Illino. That's Bill Clutter, a private investigator. On the long drive to the park, Kimberly, who has been taking prescription medicine for her migraines, starts to feel nauseous. Her husband, Christopher, looks for a place to stop. Over into a frontage road and parks in front of a seal vontur He gets out of the car, checks the tires, tightens the strap on the luggage rack. About fifteen minutes go by, and then Christopher is seen near the main road by a passing driver. He's bleeding from two gunshot wounds, one in the left arm and the other in the left thigh. The driver stops and offers help. They call nine one one. First responders soon arrive on scene. They go to Christopher's vehicle and find the worst thing possible. Kimberly is slumped in the passenger seat with an apparent self inflicted gunshot wound. The gun is on the floor at her feet. Abigail, Cassandra, and Blake are all buckled in their seats, but they've each been shot twice. Christopher's entire family is dead. He's taken to the hospital and treated for his injuries, then, still in his hospital gown, interrogated for the next fourteen hours. Detectives want answers, but Christopher doesn't have them. You say you didn't hear any type of gunshots or anything like that. No, okay, At no point did you see anybody? Okay? No, I think him many kids. Okay. It's hard to hear Christopher in this tape. He's speaking in a low voice. He's withdrawn. He puts his head down a lot. Tell me what you thought may possibly have happened. I think I think I was a kim gun old my gun. If she got a cold of your gun, what do you think she did? She shot me? He thinks she show I guess I don't know. I don't think she's capable. Man, did you catch that? He says he doesn't think his wife is capable of this. Did you see her doing no? Christopher says he didn't see his wife shoot his children, and he's confused about what happened, thus gonna go for Helen. Okay, you remember you saying that? No, particularly, I'm repeating back to you what you told me. Well, you guys asked exactly how. I don't remember. If I say kim more for help, for help, I don't remember other than I'm willing for help. As the interrogation continues, the detectives become more and more frustrated with Christopher's incomplete version of events. They accuse him of killing his family. So you get you get her in your shot, and you don't know how tough you got her, Oh man, stop bullshit. Police arrest Christopher Vaughan. He's charged with four counts of murder. Prosecutors believe Christopher got out of the car, walked around to the front passenger side window, and shot his wife under her chin to make it appear self inflicted, then leaned in her window and shot each of his three children, and then he shot himself to cover it up. Blood stain pattern analysis is a key part of the prosecution's case. Investigators believe that Christopher left a bloodstain on Kimberly's seatbelt buckle while staging the murder suicide. At trial, the state paints a picture of what kind of husband Christopher was, that he spent thousands of dollars at a strip club shortly before the shootings, that he had cheated on his wife during a work trip. He's convicted and receives four life sentences, one for each member of his family. But years later, Christopher says he does remember what happened that day, As hard as it is to imagine, Kimberly did it, and there may be evidence to prove it. I'm Molly Herman and this is CSI on trial. Two or three stays are really not enough to call something an impacts patter from gunshot that's going to put someone in prison the rest of her life. Thought that making up a lie was gonna get you home center. What is it about a bite mark that we make a dentist, an expert in this area, who shot at you. He said, I will sit in this jail, and I will rot before I take a plea bark. The problem with forensic science in the criminal legal system today is that it's an awful lot of forensic and not an awful lot of science. Episode four. Blood Stained pattern analysis. Blood stain pattern analysis, or BPA involves studying the size, shape, and distribution of bloodstains at a crime scene. It was a famous case in the nineteen fifties that established BPA as a prosecutorial tool, the Sam Shephard case in nineteen fifty five. Stuart James is a blood stain pattern analyst. He was a physician and he was accused of beating his wife to death in her bed at their house. He was also having an affair with his laboratory analysts at the time, so everything, as far as the police are concerned, was fitting into him committing the sumicide. Shepherd was found guilty, but he appealed. Famed attorney f Lee Bailey represented him and brought in doctor Paul Kirk, an expert in blood stain pattern analysis. Paul Kirk wrote an affidavit which led to the ultimate testimony and overturning of a conviction, and Sam Shepard was acquitted in his second trial. Kirk's work sparked the interest of a chemist named Herbert McDonell, who started researching BPA by performing experiments. The legend has it, I don't know if this is true or not, is that in order to run something approaching experiments, he shot a bunch of dogs. That's Attorney Richard Cayman, And that rumor is true, or at least McDonnell himself confirmed it. Stuart James again, he taught the first basic course in blood Saint Patter and Analysis down in Jackson, Mississippi. He also created a small textbook and a laboratory manual. McDonnell founded the Laboratory of Forensic Science and named himself as director. It was a small operation, run out of the basement of his house, but he still managed to secure a grant from the Department of Justice in nineteen seventy one. Soon he was teaching the basics of BPA to police departments across the country, advertising no minimum educational requirements needed to be accepted into the class. Richard came in again, and so then you have first McDonald and then any number of other people, starting with former police officers who made it into a very lucrative post police career, Herbert McDonald became a sought after expert witness. He testified in one of the most famous criminal trials of the twentieth century, the O. J. Simpson case. Press McDonald, in your expert opinion, and based on the experiments that you conducted, could the smearing of the Bundy glove and the Rockingham glove with blood on the evening of June twelfth, nineteen ninety four account for ten to fifteen send shrinkage in those cloths. I can't imagine it's at all possible. No, So what exactly is a blood stained pattern analyst looking for? They matched patterns made by blood to patterns they've seen before. It's like working backwards from the bloodstains. They try to de code the sequence of events, the weapon used, and even who did it. Here's Stewart again, our BPA expert. We have three categories. Passive bloodstains, spatter, bloodstains, altered bloodstains. So passive, spatter and altered. Let's start with passive. We're talking about blood stains that have been produced as a result of very little energy blood dripping, blood transfer from a bloody object to a non bloody object like drops of blood dripping off a knife onto the floor. Then we have spatter. It's the result of force or impact. This is probably the kind of blood stain you imagine when you think of a crime scene or when watching CSI. You have spatter from beatings, spatter from gunshot, you have spatter from arterial bleeding. You have spatter from a expiration of bloodstains coming from injury to the chest or the airway. And then there's altered blood stains. How can a bloodstain get altered? Well, you can be altered by drying, It can be altered by clotting. It can be altered by a suspect, for example taking a shower and leaving a bloody bar soap and some blood in the shower. So those are the three types, but for now let's focus on spatter. Anita Zanin conducts tests to recreate blood spatter from a gunshot. So what comes back toward the muzzle of the gun or towards the shooter is known as back spatter, and what goes out the exit wound is as forward spatter. And the further you go, the lass concentrated spatter you get, and the larger size. You see, kind of like the difference between trying to throw a handful of flower versus a handful of rocks. The rocks are going to go farther than the flower. Anita tells us that there are a lot of variables that will impact the spatter from gunshots, like the caliber of the gun or the type of ammunition. Backspatter on clothing can also be used to implicate a suspect. Let's go back to Herbert McDonald and the proliferation of BPA. Not everyone in the court system immediately accepted it. By the nineteen eighties, defense attorneys began appealing cases based on BPA evidence, saying that McDonald's testimony was not scientific. They asked, how can you prove it's reliable. McDonald defended his analysis as reliable to quote a reasonable degree of science sentific certainty. But remember law Professor J. Koehler from Episode one, to a reasonable degree of scientific certainty. It is kind of a bogus phrase. It doesn't really have any meaning, but it was too late. In nineteen eighty Iowa's Supreme Court backed the use of BPA as evidence, specifically citing McDonald's expert testimony four other states soon followed. And remember what we've learned about the importance of precedent. BPA. Testimony from hundreds of McDonald's students goes on to set precedent in at least thirteen more states within a decade. It's widely accepted in US courtrooms and all that history. That precedent comes into play when an expert testifies that a former Indiana state trooper murdered his family in cold blood, just repeatedly, over and over, I'm telling you he's wrong, he's wrong, he's wrong, he's wrong, he's wrong. Not do this, I'd likely my kids dead. Get everybody out here in my house. Everything to be okay, all right, we're gonna get out my hair take not okay, get everybody out of here now. My name is David cam I was wrongfully convicted of the murders of my wife Kim, my seven year old son Brad, and my five year old daughter Jill in two thousand and two. I was eventually exonerated, acquitted, and twenty thirteen. And this is my story. It's September twenty eighth, two thousand. Former Indiana State true David cam arrives home after playing basketball at his local church. His wife, Kimberly Cam is lying on the garage floor in a pool of her own blood. His young children, Jill and Bradley, are shot to death in the backseat of Kim's Ford Bronco. Investigators immediately focus in on David's T shirt, which is spattered with blood. Police call longtime BPA practitioner Rod Engler to the scene, but Rod was busy and sent his protege, Robert Stitz. As David Cam tells it, he went through the scene and based upon his conclusions of the things that he saw within that first forty eight hours or so, a probably cause affidavit was put together, with the majority of it coming from his analysis of the scene and various things associated with it, including my shirt. Law enforcement tested the T shirt and eight tiny spots were identified as blood belonging to Jill Cam, David's five year old daughter. Travis Kircher covered the Cam case. Basically, what they were saying was that these dots were something called high velocity impact spatter. That's spatter, the prosecution would argue, meant that David Cam was within three feet of his daughter Jill when she was murdered. They're arguing that the bullet when it hit Jill, her blood spattered backward and pulverized, which made it so small that it hit his shirt in this pattern of these tiny dots. David says he got the blood on his shirt from leaning across his daughter's body to try to resuscitate his son, Brad. Detectives tell David that science is driving the investigation. They started telling me about, well, you know, the prosecutors brought the end this expert, Dave, and he says, you've got high velocity impact spatter on your shirt and that means you had to be there, etc, Etc. Etc. And I just I let lease, I mean, I knew right then what they were trying to do. They were trying to blame me, and I knew that whoever this person was, that they were wrong. Seventy two hours after David finds his family murdered, he's arrested. I went from being a husband and a father to being incarcerated and accused of the murders. There's no way to describe what that experience was like. A trial, the prosecution paints an unflattering picture of David, who was known to have had extramarital affairs. But their physical evidence is the blood spatter, those dots on his shirt and blood on his sneaker. Both BPA Expert's Stites and Englert testify at the trial. Here's part of Englert's testiment read by a voice actor. It's the type of pattern you'd expect to see only if this particular garment is within the zone of the backspatter that was created in that explosive scene in that one moment in the shot to Jill cam. But David has an alibi ten witnesses who all testify that he was with them at church playing basketball. The prosecution has an implausible explanation. They use those eight tiny specs of blood to try to assert that I had been there previously, approximately an hour and a half prior to my actual time of arrival, and based upon that they alleged that I had left the basketball gym and the other ten basketball players driven home, murdered my family, got in my vehicle, driven back to the gym with blood on my shirt, and went back in and started playing again. But wouldn't he have gotten bloodstains in his vehicle if he drove it after the murders. There's no blood anywhere in my truck. So the basketball players they would have to see the blood, right, None of them did. They all testified there was no blood on Dave. I had no blood on me. But the jury believes the prosecution experts. David is convicted and sentenced to one hundred and ninety five years in prison. For the first six months he held out hope. I mean every time I heard that doorpop or keys rattling outside that door, I thought to myself, this is going to be the time. This is going to be the moment they figured it out. They know it wasn't me. Remember in episode one, how we told you there have been national reports that question the science behind some of these forensic methods. Well, here's what the National Academy of Sciences set about BPA in two thousand and nine. Quote the uncertainties associated with blood stain pattern analysis are enormous end quote. The few studies that do exist on BPA have troubling inconsistencies. A two sixteen study on the reliability of blood stain pattern matching on fabrics revealed that analysts were incorrect twenty three percent of the time. Another study revealed that analysts could only tell which direction blood stains were swiped left, right, up or down sixty eight percent of the time, and in two fifteen a research paper warned that blood stains on textiles are not reliable because the material may interact with, distort, and alter the stain in many different ways. Blood is a complex fluid because it has plasma, it has proteins, it has white blood cells, it has red blood cells, and each of these things helps it behave a little differently, sometimes a little strangely, compared to what our kind of instinct is with something like water. Nicole's Sharp is a scientist with a PhD specializing in fluid dynamics. So in fluid dynamics, I think we're pretty confident in our ability to say, if I start out with these conditions, this is the kind of result that I expect. And so in a perfect world, with perfect knowledge, we can say, all right, I start here, I end up here, this is what the blood saint should look like. Practically speaking, though, you're not going to find anyone who's going to have enough confidence in our knowledge of the situation that we could play it out that way. And I think even less confidence in being able to look at the remnant of the situation and say exactly what happened. With all that context, we returned to the case of David Cam. He'd been incarcerated for two years when his verdict was overturned because of prejudicial testimony, in other words, for reasons not related to the forensic evidence. In the new trial, Cam's attorneys focused on a key piece of evidence that had been pushed aside in the earlier investigation, a gray prison issue sweatshirt that had been swept into David's son Bradley's body bag. It's a gray Haynes. It's got like seven numbers written on it, and it also has the name Backbone written on the inside of the caller. Those seven numbers are a Department of Corrections ID number. During the first trial, the defense had asked the prosecutor to run the sweatshirt through Codus, which is a program that can search through local, state, and national DNA databases. The prosecutor said there were no matches. Before the second trial, it was revealed that the first prosecutor, by this time there is a different prosecutor, had never sent it to codis, that that simply had not occurred, and that he had lied to the defense. Richard Cayman represents David at his second trial and requests the sweatshirt be run through CODIS again and it came back to Charles Bonnet, who had been in prison until shortly before the Camp family was murdered. Charles Bonnet aka Backbone, a recent PAROLEI who had served almost ten years for abducting three female undergrads, and because he'd been in prison, his DNA was in the database, and so had that been done, Bonnet would have surfaced before the first trial. A palm print on the side of kim Cam's Bronco matched to Bonet, as did another odd clue, Kimberly's shoes, which were neatly placed on the top of the car. That was a calling card for Bonnet. He had a foot fetish and was actually known as the Shoe Bandit. When taken in for questioning, Bonnet gave a number of conflicting statements before implicating David. I've seen countless investigations where a guy like Bonnet is arrested and the police end up charging him because the evidence is so powerful. But here it was tell us how you helped David Cam kill his family, and he was smart enough to understand this was what they wanted to hear. Despite the match with Bonnet, blood spatter, experts who testified it the first trial maintained that David had to be involved, says Richard Caman. Essentially the same experts who had said in the first trial this murder was committed by one person acting alone, looked at the jury and said two people did this, and I can tell that two people did this. Both David cam and Charles Bonnet were found guilty. David spent another three years in prison until his conviction was overturned again, leading to a third trial. This time Robert Stites, the protege and expert witness sent to the crime scene by Rod Englert, admits he perjured himself when he claimed to be a crime scene reconstructionist and college professor working on a PhD in fluid dynamics. All of those credentials were made up, but it still comes down to that blood on David's shirt, blood from his five year old daughter. Travis Kircher was watching all of this from a seat in the courtroom. Blood Stained pattern analysis experts arguing back and forth, you know, what are these dots, What do they mean? If you're the prosecution, the reason the dots are so small is because they're pulverized. It's impacts patter. If you're the defense, it's you know, Jill's impact of her bloody hair. And I cannot stress how long this went on. Stuart James testified on behalf of the defense, two or three stains are really not enough to call something an impacts pattern from gunshot that's going to put someone in prison the rest of their life. David's attorney, Richard Cayman explains the defense often has to bring in its own BPA experts to counter the prosecution's experts. If you've got three people on one side and three people on the other saying exactly the opposite, you're basically into a coin toss. And that's not science, that's just a guess. The jury deliberated for ten hours. David cam was found not guilty on all counts the state had ignored, exonerating evidence an alibi confirmed by ten witnesses, the sweatshirt, the handprint, the shoes, in favor of the eight tiny specks of blood. I think it really needs to be said over and over and over again. This is not a close case. David Cam was innocent. He spent thirteen years as an innocent man in prison, and there simply shouldn't be any question in anybody's mind about that. David's been out of prison for almost a decade. He works for his family's business, he's remarried, but the trauma is still there. It is an impossible situation to be in when you're crying out from the depths of your soul and telling people that you're innocent and this is my family I lost. There's no way to describe that. But this bloodstained stuff, let's hopeus pocus. I don't know how you stop it. It's a freight train. That's the same freight train that's barreled toward Christopher Vaughan. He's the man we told you about at the beginning of the episode. Like David Cam, he's accused of murdering his entire family, and BPA evidence is presented as proof. Here's the prosecution's version of events in the case against Christopher Vaughan, who was accused of murdering his wife and three children. On the way to a water park. He pulls over, gets out of the car, walks around to the front passenger side, positions the gun under his wife's chin, pointing upwards, and fires. Then he leans in over his wife's body and shoots his three children. Christopher then shoots himself twice, once in the left arm and once in the upper left thigh, but he realizes he hasn't properly staged the crime scene. He needs it to look like his wife murdered their children and took her own life, so he plants the gun near Kimberly and unbuckles her seatbelt. But he's bleeding from just shooting himself, so he leaves a bloodstain on it. The jury took less than an hour to convict Vaughan. He's given four life sentences. Bill Clutter, the private investigator you heard from earlier, thinks Christopher Vaughan is innocent. He's taken up the case as part of a nonprofit advocacy organization. Bill focuses on the accuracy of the blood stained pattern analysis. When the crime scene investigators arrive, they noticed h transfer stain of blood on the passenger seatbelt that was found unbuckled, and there was a crime scene investigator in training who suggested pulling the seat belt strap out, and they revealed that there was this large saturation stain of blood from passive blood dripping onto that seat belt. When they do DNA testing, it turns out to be Christopher Vaughan's blood. And then it became the theory of the lead investigator of that case that Christopher Vaughan somehow unbuckled his wife's seat belt after she was shot to stage the crime scene. Until recently, Christopher had maintained that he couldn't remember what happened that day, But in a letter to his parents in twenty twenty one, nine years after he was convicted, Christopher admits he did remember, he just simply couldn't face it, and then once he became a suspect, he was afraid to admit he had lost. What he says happened is that he pulled over because Kim felt ill. He got out and walked behind the vehicle to make sure the car top carrier hadn't come loose. While behind the vehicle, Christopher hears what he describes as the inside of the truck exploding. He runs back to the driver's side door and finds Kim with a gun in her hand. When Chris leans into the car to try to grab it. She shoots him twice. Here's part of the letter Christopher sent to his parents, read by a voice actor. Kim looked at me and said, you will not take my kids. You killed them. She then turned the gun on herself and fired. I got back in to check the kids. Nothing could be done. I thought to drive the truck. Kim was slumped, so I tried to buckle her. My hands shook badly. I couldn't buckle the belt, couldn't drive the truck. I got to the road to get help. Bill creates a reconstruction of the crime scene to test this version of events. He has actors playing Christopher and Kimberly, and he gets the same vehicle make and model, and what he discovers is consistent with the large blood saturation stain found on the seatbelt buckle, the blood that belonged to Christopher. So did the stain come from unbuckling Kimberly and staging the scene or trying to buckle her to drive away. What we know for certain is that the same bloodstain can tell two completely different stories. The pitfall of bloodstain interpretations is you can fall into that trap of seeing what you want to see when you're looking at bloodstain patterns or trying to figure out what could explain a particular pattern, and there's less than certainty. Clutter's reconstruction reveals that the blood stained pattern analysis that convicted Christopher is at best inconclusive. Of course, Christopher's version leads to the unthinkable, a mother taking the lives of her own children. Why would Kimberly do this? It's an impossible question to answer. One potential clue is the medication she was taking for her migraines. Clinical trials have shown that those prescriptions can cause psychiatric and behavioral disturbances and increase the risk of suicide. Christopher Vaughan has been in prison for over fourteen years. Bill Clutter hopes his work will open the door to a re examination of the case, and a new attorney is working to overturn the conviction. So what is the answer? Do we just ignore blood at a crime? Of course not. The answer is we just don't call something a science if it isn't a science. It is one thing. If an investigator tells a jury what they saw at the crime scene and how that led to the next step in their investigation. It is a whole other thing if someone is allowed to present themselves as an expert to a jury when the field they are an expert in isn't scientifically valid or reliable. As Nicole the fluid dynamic scientist told me, I think it's really dangerous when people use the trappings of science to give a level of authority to an idea that doesn't necessarily have any scientific merit. I think it's easy to see something that seems scientific and to ascribe it the level of certainty and trust that we would give to something that has gone through a full scientific process and peer review and verification and validation and so forth. David cam isn't optimistic that change will come. Almost every day someone is being released and exonerated, and you know, until there's some recognition on behalf of those within the system and those who are part of the citizenry to request and demand those changes, it's just going to continue to happen. But I don't I'm not real hopeful that there's going to be change next time. On CSI on trial the murder of an NBA star's grandfather and the shoe prints that lead to a conviction, Detective came out and he asked me, did I know Nathan and Jones and that I knew he had been murdered and seen it on a news and he's say Aya, sons, o'deates Mek in the middle of it. CSI on Trial is a co production of iHeart Podcasts and School of Humans, based on the Curiosity stream series CSI on Trial, created by Eleanor Grant and produced by the Biscuit Factory. You can watch all six episodes of the video series right now at curiosity stream dot com. This episode is hosted and written by me Molly Herman and researched by Katie Dunn and myself. Our producer is Miranda Hawkins. Jessica Metzker is the senior producer. Virginia Prescott, Jason English, Brandon Barr and L. C. Crowley are the executive producers. Sound design in mix by Miranda Hawkins, Voice acting by Mike Coscarelli and Jeremy Thall. Special thanks to John Higgins, Rob Burke, Rob Lyle, and Brandon Craigie. If you are enjoying the show, leave a review in your favorite podcast app. Check out the Curiosity Audio Network for podcasts covering history, pop culture, true crime, and more. School of Humans,

This episode contains details of gun violence against children. Please take care where and when you listen. It's a summer day in June two thousand and seven. Christopher Vaughan and his thirty four year old wife, Kimberly, and their three children pile into their suv early in the morning. Abigail is twelve, Cassandra is eleven, and Blake is eight. The family is on their way to a water park from Oswego, Illinois, where they lived outside of Chicago. They were going to drive about three hours down to Springfield, Illino. That's Bill Clutter, a private investigator. On the long drive to the park, Kimberly, who has been taking prescription medicine for her migraines, starts to feel nauseous. Her husband, Christopher, looks for a place to stop. Over into a frontage road and parks in front of a seal vontur He gets out of the car, checks the tires, tightens the strap on the luggage rack. About fifteen minutes go by, and then Christopher is seen near the main road by a passing driver. He's bleeding from two gunshot wounds, one in the left arm and the other in the left thigh. The driver stops and offers help. They call nine one one. First responders soon arrive on scene. They go to Christopher's vehicle and find the worst thing possible. Kimberly is slumped in the passenger seat with an apparent self inflicted gunshot wound. The gun is on the floor at her feet. Abigail, Cassandra, and Blake are all buckled in their seats, but they've each been shot twice. Christopher's entire family is dead. He's taken to the hospital and treated for his injuries, then, still in his hospital gown, interrogated for the next fourteen hours. Detectives want answers, but Christopher doesn't have them. You say you didn't hear any type of gunshots or anything like that. No, okay, At no point did you see anybody? Okay? No, I think him many kids. Okay. It's hard to hear Christopher in this tape. He's speaking in a low voice. He's withdrawn. He puts his head down a lot. Tell me what you thought may possibly have happened. I think I think I was a kim gun old my gun. If she got a cold of your gun, what do you think she did? She shot me? He thinks she show I guess I don't know. I don't think she's capable. Man, did you catch that? He says he doesn't think his wife is capable of this. Did you see her doing no? Christopher says he didn't see his wife shoot his children, and he's confused about what happened, thus gonna go for Helen. Okay, you remember you saying that? No, particularly, I'm repeating back to you what you told me. Well, you guys asked exactly how. I don't remember. If I say kim more for help, for help, I don't remember other than I'm willing for help. As the interrogation continues, the detectives become more and more frustrated with Christopher's incomplete version of events. They accuse him of killing his family. So you get you get her in your shot, and you don't know how tough you got her, Oh man, stop bullshit. Police arrest Christopher Vaughan. He's charged with four counts of murder. Prosecutors believe Christopher got out of the car, walked around to the front passenger side window, and shot his wife under her chin to make it appear self inflicted, then leaned in her window and shot each of his three children, and then he shot himself to cover it up. Blood stain pattern analysis is a key part of the prosecution's case. Investigators believe that Christopher left a bloodstain on Kimberly's seatbelt buckle while staging the murder suicide. At trial, the state paints a picture of what kind of husband Christopher was, that he spent thousands of dollars at a strip club shortly before the shootings, that he had cheated on his wife during a work trip. He's convicted and receives four life sentences, one for each member of his family. But years later, Christopher says he does remember what happened that day, As hard as it is to imagine, Kimberly did it, and there may be evidence to prove it. I'm Molly Herman and this is CSI on trial. Two or three stays are really not enough to call something an impacts patter from gunshot that's going to put someone in prison the rest of her life. Thought that making up a lie was gonna get you home center. What is it about a bite mark that we make a dentist, an expert in this area, who shot at you. He said, I will sit in this jail, and I will rot before I take a plea bark. The problem with forensic science in the criminal legal system today is that it's an awful lot of forensic and not an awful lot of science. Episode four. Blood Stained pattern analysis. Blood stain pattern analysis, or BPA involves studying the size, shape, and distribution of bloodstains at a crime scene. It was a famous case in the nineteen fifties that established BPA as a prosecutorial tool, the Sam Shephard case in nineteen fifty five. Stuart James is a blood stain pattern analyst. He was a physician and he was accused of beating his wife to death in her bed at their house. He was also having an affair with his laboratory analysts at the time, so everything, as far as the police are concerned, was fitting into him committing the sumicide. Shepherd was found guilty, but he appealed. Famed attorney f Lee Bailey represented him and brought in doctor Paul Kirk, an expert in blood stain pattern analysis. Paul Kirk wrote an affidavit which led to the ultimate testimony and overturning of a conviction, and Sam Shepard was acquitted in his second trial. Kirk's work sparked the interest of a chemist named Herbert McDonell, who started researching BPA by performing experiments. The legend has it, I don't know if this is true or not, is that in order to run something approaching experiments, he shot a bunch of dogs. That's Attorney Richard Cayman, And that rumor is true, or at least McDonnell himself confirmed it. Stuart James again, he taught the first basic course in blood Saint Patter and Analysis down in Jackson, Mississippi. He also created a small textbook and a laboratory manual. McDonnell founded the Laboratory of Forensic Science and named himself as director. It was a small operation, run out of the basement of his house, but he still managed to secure a grant from the Department of Justice in nineteen seventy one. Soon he was teaching the basics of BPA to police departments across the country, advertising no minimum educational requirements needed to be accepted into the class. Richard came in again, and so then you have first McDonald and then any number of other people, starting with former police officers who made it into a very lucrative post police career, Herbert McDonald became a sought after expert witness. He testified in one of the most famous criminal trials of the twentieth century, the O. J. Simpson case. Press McDonald, in your expert opinion, and based on the experiments that you conducted, could the smearing of the Bundy glove and the Rockingham glove with blood on the evening of June twelfth, nineteen ninety four account for ten to fifteen send shrinkage in those cloths. I can't imagine it's at all possible. No, So what exactly is a blood stained pattern analyst looking for? They matched patterns made by blood to patterns they've seen before. It's like working backwards from the bloodstains. They try to de code the sequence of events, the weapon used, and even who did it. Here's Stewart again, our BPA expert. We have three categories. Passive bloodstains, spatter, bloodstains, altered bloodstains. So passive, spatter and altered. Let's start with passive. We're talking about blood stains that have been produced as a result of very little energy blood dripping, blood transfer from a bloody object to a non bloody object like drops of blood dripping off a knife onto the floor. Then we have spatter. It's the result of force or impact. This is probably the kind of blood stain you imagine when you think of a crime scene or when watching CSI. You have spatter from beatings, spatter from gunshot, you have spatter from arterial bleeding. You have spatter from a expiration of bloodstains coming from injury to the chest or the airway. And then there's altered blood stains. How can a bloodstain get altered? Well, you can be altered by drying, It can be altered by clotting. It can be altered by a suspect, for example taking a shower and leaving a bloody bar soap and some blood in the shower. So those are the three types, but for now let's focus on spatter. Anita Zanin conducts tests to recreate blood spatter from a gunshot. So what comes back toward the muzzle of the gun or towards the shooter is known as back spatter, and what goes out the exit wound is as forward spatter. And the further you go, the lass concentrated spatter you get, and the larger size. You see, kind of like the difference between trying to throw a handful of flower versus a handful of rocks. The rocks are going to go farther than the flower. Anita tells us that there are a lot of variables that will impact the spatter from gunshots, like the caliber of the gun or the type of ammunition. Backspatter on clothing can also be used to implicate a suspect. Let's go back to Herbert McDonald and the proliferation of BPA. Not everyone in the court system immediately accepted it. By the nineteen eighties, defense attorneys began appealing cases based on BPA evidence, saying that McDonald's testimony was not scientific. They asked, how can you prove it's reliable. McDonald defended his analysis as reliable to quote a reasonable degree of science sentific certainty. But remember law Professor J. Koehler from Episode one, to a reasonable degree of scientific certainty. It is kind of a bogus phrase. It doesn't really have any meaning, but it was too late. In nineteen eighty Iowa's Supreme Court backed the use of BPA as evidence, specifically citing McDonald's expert testimony four other states soon followed. And remember what we've learned about the importance of precedent. BPA. Testimony from hundreds of McDonald's students goes on to set precedent in at least thirteen more states within a decade. It's widely accepted in US courtrooms and all that history. That precedent comes into play when an expert testifies that a former Indiana state trooper murdered his family in cold blood, just repeatedly, over and over, I'm telling you he's wrong, he's wrong, he's wrong, he's wrong, he's wrong. Not do this, I'd likely my kids dead. Get everybody out here in my house. Everything to be okay, all right, we're gonna get out my hair take not okay, get everybody out of here now. My name is David cam I was wrongfully convicted of the murders of my wife Kim, my seven year old son Brad, and my five year old daughter Jill in two thousand and two. I was eventually exonerated, acquitted, and twenty thirteen. And this is my story. It's September twenty eighth, two thousand. Former Indiana State true David cam arrives home after playing basketball at his local church. His wife, Kimberly Cam is lying on the garage floor in a pool of her own blood. His young children, Jill and Bradley, are shot to death in the backseat of Kim's Ford Bronco. Investigators immediately focus in on David's T shirt, which is spattered with blood. Police call longtime BPA practitioner Rod Engler to the scene, but Rod was busy and sent his protege, Robert Stitz. As David Cam tells it, he went through the scene and based upon his conclusions of the things that he saw within that first forty eight hours or so, a probably cause affidavit was put together, with the majority of it coming from his analysis of the scene and various things associated with it, including my shirt. Law enforcement tested the T shirt and eight tiny spots were identified as blood belonging to Jill Cam, David's five year old daughter. Travis Kircher covered the Cam case. Basically, what they were saying was that these dots were something called high velocity impact spatter. That's spatter, the prosecution would argue, meant that David Cam was within three feet of his daughter Jill when she was murdered. They're arguing that the bullet when it hit Jill, her blood spattered backward and pulverized, which made it so small that it hit his shirt in this pattern of these tiny dots. David says he got the blood on his shirt from leaning across his daughter's body to try to resuscitate his son, Brad. Detectives tell David that science is driving the investigation. They started telling me about, well, you know, the prosecutors brought the end this expert, Dave, and he says, you've got high velocity impact spatter on your shirt and that means you had to be there, etc, Etc. Etc. And I just I let lease, I mean, I knew right then what they were trying to do. They were trying to blame me, and I knew that whoever this person was, that they were wrong. Seventy two hours after David finds his family murdered, he's arrested. I went from being a husband and a father to being incarcerated and accused of the murders. There's no way to describe what that experience was like. A trial, the prosecution paints an unflattering picture of David, who was known to have had extramarital affairs. But their physical evidence is the blood spatter, those dots on his shirt and blood on his sneaker. Both BPA Expert's Stites and Englert testify at the trial. Here's part of Englert's testiment read by a voice actor. It's the type of pattern you'd expect to see only if this particular garment is within the zone of the backspatter that was created in that explosive scene in that one moment in the shot to Jill cam. But David has an alibi ten witnesses who all testify that he was with them at church playing basketball. The prosecution has an implausible explanation. They use those eight tiny specs of blood to try to assert that I had been there previously, approximately an hour and a half prior to my actual time of arrival, and based upon that they alleged that I had left the basketball gym and the other ten basketball players driven home, murdered my family, got in my vehicle, driven back to the gym with blood on my shirt, and went back in and started playing again. But wouldn't he have gotten bloodstains in his vehicle if he drove it after the murders. There's no blood anywhere in my truck. So the basketball players they would have to see the blood, right, None of them did. They all testified there was no blood on Dave. I had no blood on me. But the jury believes the prosecution experts. David is convicted and sentenced to one hundred and ninety five years in prison. For the first six months he held out hope. I mean every time I heard that doorpop or keys rattling outside that door, I thought to myself, this is going to be the time. This is going to be the moment they figured it out. They know it wasn't me. Remember in episode one, how we told you there have been national reports that question the science behind some of these forensic methods. Well, here's what the National Academy of Sciences set about BPA in two thousand and nine. Quote the uncertainties associated with blood stain pattern analysis are enormous end quote. The few studies that do exist on BPA have troubling inconsistencies. A two sixteen study on the reliability of blood stain pattern matching on fabrics revealed that analysts were incorrect twenty three percent of the time. Another study revealed that analysts could only tell which direction blood stains were swiped left, right, up or down sixty eight percent of the time, and in two fifteen a research paper warned that blood stains on textiles are not reliable because the material may interact with, distort, and alter the stain in many different ways. Blood is a complex fluid because it has plasma, it has proteins, it has white blood cells, it has red blood cells, and each of these things helps it behave a little differently, sometimes a little strangely, compared to what our kind of instinct is with something like water. Nicole's Sharp is a scientist with a PhD specializing in fluid dynamics. So in fluid dynamics, I think we're pretty confident in our ability to say, if I start out with these conditions, this is the kind of result that I expect. And so in a perfect world, with perfect knowledge, we can say, all right, I start here, I end up here, this is what the blood saint should look like. Practically speaking, though, you're not going to find anyone who's going to have enough confidence in our knowledge of the situation that we could play it out that way. And I think even less confidence in being able to look at the remnant of the situation and say exactly what happened. With all that context, we returned to the case of David Cam. He'd been incarcerated for two years when his verdict was overturned because of prejudicial testimony, in other words, for reasons not related to the forensic evidence. In the new trial, Cam's attorneys focused on a key piece of evidence that had been pushed aside in the earlier investigation, a gray prison issue sweatshirt that had been swept into David's son Bradley's body bag. It's a gray Haynes. It's got like seven numbers written on it, and it also has the name Backbone written on the inside of the caller. Those seven numbers are a Department of Corrections ID number. During the first trial, the defense had asked the prosecutor to run the sweatshirt through Codus, which is a program that can search through local, state, and national DNA databases. The prosecutor said there were no matches. Before the second trial, it was revealed that the first prosecutor, by this time there is a different prosecutor, had never sent it to codis, that that simply had not occurred, and that he had lied to the defense. Richard Cayman represents David at his second trial and requests the sweatshirt be run through CODIS again and it came back to Charles Bonnet, who had been in prison until shortly before the Camp family was murdered. Charles Bonnet aka Backbone, a recent PAROLEI who had served almost ten years for abducting three female undergrads, and because he'd been in prison, his DNA was in the database, and so had that been done, Bonnet would have surfaced before the first trial. A palm print on the side of kim Cam's Bronco matched to Bonet, as did another odd clue, Kimberly's shoes, which were neatly placed on the top of the car. That was a calling card for Bonnet. He had a foot fetish and was actually known as the Shoe Bandit. When taken in for questioning, Bonnet gave a number of conflicting statements before implicating David. I've seen countless investigations where a guy like Bonnet is arrested and the police end up charging him because the evidence is so powerful. But here it was tell us how you helped David Cam kill his family, and he was smart enough to understand this was what they wanted to hear. Despite the match with Bonnet, blood spatter, experts who testified it the first trial maintained that David had to be involved, says Richard Caman. Essentially the same experts who had said in the first trial this murder was committed by one person acting alone, looked at the jury and said two people did this, and I can tell that two people did this. Both David cam and Charles Bonnet were found guilty. David spent another three years in prison until his conviction was overturned again, leading to a third trial. This time Robert Stites, the protege and expert witness sent to the crime scene by Rod Englert, admits he perjured himself when he claimed to be a crime scene reconstructionist and college professor working on a PhD in fluid dynamics. All of those credentials were made up, but it still comes down to that blood on David's shirt, blood from his five year old daughter. Travis Kircher was watching all of this from a seat in the courtroom. Blood Stained pattern analysis experts arguing back and forth, you know, what are these dots, What do they mean? If you're the prosecution, the reason the dots are so small is because they're pulverized. It's impacts patter. If you're the defense, it's you know, Jill's impact of her bloody hair. And I cannot stress how long this went on. Stuart James testified on behalf of the defense, two or three stains are really not enough to call something an impacts pattern from gunshot that's going to put someone in prison the rest of their life. David's attorney, Richard Cayman explains the defense often has to bring in its own BPA experts to counter the prosecution's experts. If you've got three people on one side and three people on the other saying exactly the opposite, you're basically into a coin toss. And that's not science, that's just a guess. The jury deliberated for ten hours. David cam was found not guilty on all counts the state had ignored, exonerating evidence an alibi confirmed by ten witnesses, the sweatshirt, the handprint, the shoes, in favor of the eight tiny specks of blood. I think it really needs to be said over and over and over again. This is not a close case. David Cam was innocent. He spent thirteen years as an innocent man in prison, and there simply shouldn't be any question in anybody's mind about that. David's been out of prison for almost a decade. He works for his family's business, he's remarried, but the trauma is still there. It is an impossible situation to be in when you're crying out from the depths of your soul and telling people that you're innocent and this is my family I lost. There's no way to describe that. But this bloodstained stuff, let's hopeus pocus. I don't know how you stop it. It's a freight train. That's the same freight train that's barreled toward Christopher Vaughan. He's the man we told you about at the beginning of the episode. Like David Cam, he's accused of murdering his entire family, and BPA evidence is presented as proof. Here's the prosecution's version of events in the case against Christopher Vaughan, who was accused of murdering his wife and three children. On the way to a water park. He pulls over, gets out of the car, walks around to the front passenger side, positions the gun under his wife's chin, pointing upwards, and fires. Then he leans in over his wife's body and shoots his three children. Christopher then shoots himself twice, once in the left arm and once in the upper left thigh, but he realizes he hasn't properly staged the crime scene. He needs it to look like his wife murdered their children and took her own life, so he plants the gun near Kimberly and unbuckles her seatbelt. But he's bleeding from just shooting himself, so he leaves a bloodstain on it. The jury took less than an hour to convict Vaughan. He's given four life sentences. Bill Clutter, the private investigator you heard from earlier, thinks Christopher Vaughan is innocent. He's taken up the case as part of a nonprofit advocacy organization. Bill focuses on the accuracy of the blood stained pattern analysis. When the crime scene investigators arrive, they noticed h transfer stain of blood on the passenger seatbelt that was found unbuckled, and there was a crime scene investigator in training who suggested pulling the seat belt strap out, and they revealed that there was this large saturation stain of blood from passive blood dripping onto that seat belt. When they do DNA testing, it turns out to be Christopher Vaughan's blood. And then it became the theory of the lead investigator of that case that Christopher Vaughan somehow unbuckled his wife's seat belt after she was shot to stage the crime scene. Until recently, Christopher had maintained that he couldn't remember what happened that day, But in a letter to his parents in twenty twenty one, nine years after he was convicted, Christopher admits he did remember, he just simply couldn't face it, and then once he became a suspect, he was afraid to admit he had lost. What he says happened is that he pulled over because Kim felt ill. He got out and walked behind the vehicle to make sure the car top carrier hadn't come loose. While behind the vehicle, Christopher hears what he describes as the inside of the truck exploding. He runs back to the driver's side door and finds Kim with a gun in her hand. When Chris leans into the car to try to grab it. She shoots him twice. Here's part of the letter Christopher sent to his parents, read by a voice actor. Kim looked at me and said, you will not take my kids. You killed them. She then turned the gun on herself and fired. I got back in to check the kids. Nothing could be done. I thought to drive the truck. Kim was slumped, so I tried to buckle her. My hands shook badly. I couldn't buckle the belt, couldn't drive the truck. I got to the road to get help. Bill creates a reconstruction of the crime scene to test this version of events. He has actors playing Christopher and Kimberly, and he gets the same vehicle make and model, and what he discovers is consistent with the large blood saturation stain found on the seatbelt buckle, the blood that belonged to Christopher. So did the stain come from unbuckling Kimberly and staging the scene or trying to buckle her to drive away. What we know for certain is that the same bloodstain can tell two completely different stories. The pitfall of bloodstain interpretations is you can fall into that trap of seeing what you want to see when you're looking at bloodstain patterns or trying to figure out what could explain a particular pattern, and there's less than certainty. Clutter's reconstruction reveals that the blood stained pattern analysis that convicted Christopher is at best inconclusive. Of course, Christopher's version leads to the unthinkable, a mother taking the lives of her own children. Why would Kimberly do this? It's an impossible question to answer. One potential clue is the medication she was taking for her migraines. Clinical trials have shown that those prescriptions can cause psychiatric and behavioral disturbances and increase the risk of suicide. Christopher Vaughan has been in prison for over fourteen years. Bill Clutter hopes his work will open the door to a re examination of the case, and a new attorney is working to overturn the conviction. So what is the answer? Do we just ignore blood at a crime? Of course not. The answer is we just don't call something a science if it isn't a science. It is one thing. If an investigator tells a jury what they saw at the crime scene and how that led to the next step in their investigation. It is a whole other thing if someone is allowed to present themselves as an expert to a jury when the field they are an expert in isn't scientifically valid or reliable. As Nicole the fluid dynamic scientist told me, I think it's really dangerous when people use the trappings of science to give a level of authority to an idea that doesn't necessarily have any scientific merit. I think it's easy to see something that seems scientific and to ascribe it the level of certainty and trust that we would give to something that has gone through a full scientific process and peer review and verification and validation and so forth. David cam isn't optimistic that change will come. Almost every day someone is being released and exonerated, and you know, until there's some recognition on behalf of those within the system and those who are part of the citizenry to request and demand those changes, it's just going to continue to happen. But I don't I'm not real hopeful that there's going to be change next time. On CSI on trial the murder of an NBA star's grandfather and the shoe prints that lead to a conviction, Detective came out and he asked me, did I know Nathan and Jones and that I knew he had been murdered and seen it on a news and he's say Aya, sons, o'deates Mek in the middle of it. CSI on Trial is a co production of iHeart Podcasts and School of Humans, based on the Curiosity stream series CSI on Trial, created by Eleanor Grant and produced by the Biscuit Factory. You can watch all six episodes of the video series right now at curiosity stream dot com. This episode is hosted and written by me Molly Herman and researched by Katie Dunn and myself. Our producer is Miranda Hawkins. Jessica Metzker is the senior producer. Virginia Prescott, Jason English, Brandon Barr and L. C. Crowley are the executive producers. Sound design in mix by Miranda Hawkins, Voice acting by Mike Coscarelli and Jeremy Thall. Special thanks to John Higgins, Rob Burke, Rob Lyle, and Brandon Craigie. If you are enjoying the show, leave a review in your favorite podcast app. Check out the Curiosity Audio Network for podcasts covering history, pop culture, true crime, and more. School of Humans,