This is part three in a four-part series. Read part one here and part two here.

There were red flags that bite mark analysis was flawed even as the first cases in the 1970s secured its use in the courtroom. For example, a 1975 study asked bite mark analysts to match bite marks made in pig skins under optimal laboratory conditions to the teeth that were used to make the marks. The error rate was 24 percent. When the analysts were asked to make their matches from photos of the marks taken 24 hours later — as is often done in criminal cases — they were wrong nine out of 10 times.

But neither proficiency test results nor a lack of scientific research to support the field seemed to bother America’s courts. By the early 1990s, judges were welcoming bite mark testimony into courts across the country. In 1990, the Supreme Court in Arizona — the state where Ray Krone would soon be wrongly convicted because of bite mark evidence — ruled that so long as a bite mark expert has been accredited, the state’s courts no longer needed to submit their opinions to a Frye test. (See part two for more about the Frye standard.) A 1995 article in the Santa Clara High Technology Law Journal found that as of 1992, bite mark matching had been admitted as evidence in 193 criminal cases across the country and had been accepted by appellate courts in more than half the states.

There had been a few critics in the 1970s and 1980s, but the practice wasn’t yet widespread enough for anyone to care. But by the early 1990s, bite mark analysts were testifying often enough to begin to raise some alarms.

Michael Bowers was one of those early critics. Bowers is a practicing dentist in Ventura County, Calif. He also has a law degree and serves as a consultant with the Ventura County Sheriff’s Office and the Ventura County Medical Examiner. Bowers joined the American Board of Forensic Odontology in 1989. While he was a member of ABFO, Bowers wrote articles for the organization’s newsletter and served on its board of directors and its credentialing committee.

But Bowers grew increasingly blunt in voicing his concerns about bite mark matching. In a 1996 article for the newsletter of the American Society of Forensic Odontologists (ASFO is an educational organization, and while there are many overlapping members between the ABFO and the ASFO, the ASFO doesn’t offer board certification), Bowers didn’t mince his words. He wrote that the “physical matching of bite marks is a non-science which was developed with little testing and no published error rate. It is supported by anecdotalism and a minuscule number of inadequate population studies.”

In another article for the ABFO newsletter the same year, Bowers encouraged the group to rein in its experts. He urged more cautious testimony, at least until the underlying assumptions behind bite mark matching could be verified or disproved with science-based research.

There is no reliable way of saying, other than colloquially, that one or more tooth marks seen in a wound are conclusively unique to just one person in the population. Because of this vacuum, value judgements abound in our discipline. Proffering the testifying expert’s years of experience is a popular means of “proving” uniqueness.” He or she has seen more bitemarks. This misses the scientific point and is misleading to a lay jury that is given the responsibility of filtering good science from bad. The confidence level of expert testimony must be based on data available to BOTH the dentist and the court. This scientific data does not exist. Until this changes, the admissibility of bitemark analysis should be limited to a “possible” determination. The odontologist doesn’t have a basis to expand an opinion beyond that.
. . . Research must progress to raise the current anecdotal level of individuation in contemporary bitemark analysis. A concerted effort to find funding and research facilities has to be done by this organization. It will be the cheapest assurance that our future in court will be positive, rather than controversial. After the research is done, the “possible” might then become “unique.”

That research didn’t happen. In the early 1990s, the FBI set up more than 20 scientific working groups to study and improve the practice of more than two dozen forensic disciplines. Some of those groups uncovered the flaws in forensic analyses that inspired a National Academy of Sciences (NAS) report in 2009. Others weren’t as successful. But notably, forensic odontology is the only widely used forensic discipline that wasn’t subjected to the scrutiny of a working group at all.

As Bowers watched the ABFO and its membership duck serious scientific scrutiny, his criticism grew stronger, and his relationship with the organization began to sour. In 1999, he conducted a bite mark “workshop” at an American Academy of Forensic Sciences (AAFS) conference. Bite mark analysts were asked to match bite marks with the teeth that made them. More than 60 percent made an incorrect identification. Bowers then published the results of his test, further agitating the bite mark community. To this day, ABFO officials refer to that 1999 test as a “workshop,” not a competency test, and insist that the results were meaningless.

“That criticism might have some validity if ABFO administered its own competency tests,” says Chris Fabricant, director of strategic litigation for the Innocence Project. “But the organization has shown no interest in testing to see if two or more of its own certified experts can look at the same set of bite marks and independently come to the same conclusion. There’s no reliability in these methods. Therefore, there’s no way to test for accuracy. That means this isn’t science. And if it isn’t science, it doesn’t belong in the courtroom.”

Increasingly frustrated with ABFO’s disinterest in keeping unscientific testimony out of criminal cases, Bowers resigned from the group in 2011. Since then, he has continued his criticisms in journal articles, presentations at conferences, a textbook, court testimony and a blog he runs with fellow dentist and bite mark matching critic David Averill.

But the pro-bite mark matching community began to fight back.

The first shot at Bowers came from Carl Hagstrom and Russell Schneider, two bite mark specialists who testified for prosecutors in the 1986 trial of Bennie Starks, an Illinois man found guilty of raping a 69-year-old woman. The testimony from Hagstrom and Schneider was the primary evidence against Starks. In 2000, DNA testing on semen found in the woman’s underwear excluded Starks as the source of the semen. But citing the bite mark testimony, Lake County, Ill., assistant state’s attorney Michael Mermel insisted that Starks was guilty and prevented the DNA profile created from the semen from being run through CODIS, the federal DNA database. Mermel added that if the semen had been taken from the woman’s vagina instead of her underwear, he’d be advocating for Starks’s release himself.

Mermel’s promise was put to the test in 2006, when a vaginal swab previously thought to have been lost was found and tested. Again the DNA profile excluded Starks. This time, Starks’s conviction was overturned by an appeals court. But despite his earlier statement, Mermel again insisted that Starks was still guilty, and again he cited the bite mark testimony from Hagstrom and Schneider. He kept Starks in prison pending another trial, positing that Starks must have bitten the woman while someone else raped her, or alternately, that the victim must have had consensual sex shortly before the incident. (The victim, who survived the attack, insisted that she hadn’t.)

Mermel was forced to resign in 2011 after an unflattering New York Times Magazine feature cited Starks’s conviction among other cases in which Mermel had concocted implausible theories after DNA testing revealed a likely wrongful conviction. Meremel’s boss was defeated in the 2012 election and shortly after taking office the following January, the new Lake County district attorney finally dropped the charges against Starks.

Bowers cited the Starks case in a presentation at the 2011 AAFS conference in Chicago. Hagstrom and Schneider sued Bowers in 2011, claiming that his presentation caused them “ridicule and a loss of business.” The two dentists argued that the appellate court never explicitly ruled that their bite mark testimony was flawed, only that Starks deserved a new trial. This was true. But given the DNA evidence, it didn’t need to. The men’s lawsuit against Bowers implicitly relied on the discredited Mermel’s still-unlikely theory: Starks must have bitten the woman while someone else raped her. Bowers settled the suit for $1,250 with each dentist, an amount significantly lower than what it would have cost him to litigate.

In October 2013, Bowers published the book “Forensic Testimony: Science, Law and Expert Evidence,” which includes essays by Bowers and other critics of modern forensics. The essays are meticulously researched and generally skeptical of a wide array of forensic disciplines. It comes down especially hard on pattern matching analysis and on bite mark matching in particular. The book was an honorable mention for a PROSE Award in law and legal studies.

Four months after the book was published, Bowers was dropped from the editorial board of the Journal of Forensic Sciences, the AAFS flagship publication. In an e-mail, editor Michael Peat told Bowers he had been “termed out” of his position due to the “need to bring on new members.” Peat did not respond to a request for comment, but other forensic specialists said in interviews for this article that the timing of Bowers’s ouster is suspicious. They point out that another member of the editorial board, Robert Barsley, is a bite mark analyst who has held numerous leadership positions at both the ABFO and the AAFS. The editorial board also includes Ken Melson, chair of the ethics committee that would later recommend Bowers’s ouster from AAFS. The board does include at least one other bite mark skeptic. So it’s at least plausible that dropping Bowers from the board wasn’t related to his criticisms of pattern-matching forensic specialties. Others speculated that with the building tension between Bowers and the ABFO, the journal may have just wanted to avoid controversy.

But then came the ethics complaint. In November 2013, two weeks after Bowers’s book was published and a month after Gerard Richardson became the latest bite mark exoneree, recently elected ABFO President Peter Loomis filed a six-page complaint against Bowers with the AAFS ethics committee. Loomis cited three cases in which he claimed Bowers had violated AAFS ethical regulations, one in 2008 and two in 2010. Loomis wasn’t present at any of the proceedings where the alleged ethical violations occurred, nor were there any complaints filed against Bowers by any of the attorneys or judges in those cases. The complaint also came as Bowers has been preparing to testify as an expert witness in two lawsuits against bite mark analysts brought by people who had been convicted by bite mark testimony and were exonerated after serving long terms in prison.

“There’s no doubt in my mind that the ethics complaint was retaliation,” says Fabricant. “Look at the timing. The complaint came a month after the high-profile exoneration of Gerard Richardson. Of all the exonerations in bite mark cases, of all the perversions of justice caused by bite mark analysts over the years, the first ethics complaint an ABFO officer ever files with the AAFS is against one of the most effective critics of bite mark analysis. This was an attempt to silence a critic.”

Michael Saks, an Arizona State University law professor and expert on forensic evidence, agrees. “It’s a beautiful example of the adversarial process in action. When you first read it, the complaint sounds as if it could have some merit. Then you read Bowers’ response. You get the context, and you realize that there’s no there there. The complaint is either badly mistaken, or it’s a transparent attempt to purge someone who has been a problem for them.”

“Bowers has been a thorn in the ABFO’s side for forever,” says Michael Risinger, a Seton Hall University law professor who specializes in law, science and expert testimony. “This certainly looks like an attempt to purge a critic. ”

To understand the significance of the complaint, it’s important to understand that the AAFS is the largest forensics organization in the country. It is the main professional body of the forensics community. While they’re technically private organizations, groups such as the AAFS and the ABFO have enormous influence over who does and doesn’t get to testify in court. “An AAFS finding that Bowers committed ethical violations would render him useless as an expert witness,” Saks says. Even if Bowers could persuade judges to continue certifying him, an opposing attorney could use the finding to discredit him to the jury.

At the time Loomis filed his complaint, the chairman of the AAFS ethics committee was Haskell Pitluck, a retired Illinois state court judge. As it turns out, Pitluck is also the legal counsel for the ABFO and a nonvoting member of the ABFO’s ethics committee. One year before Loomis’s complaint, the ABFO established the “Haskell Pitluck Award,” which the organization presents annually to someone who has “served the ABFO community in an exemplary fashion.” The first ABFO Haskell Pitluck Award was given in February 2012. The first recipient: Haskell Pitluck. And the person who would determine whether there was any merit to the complaint filed by the ABFO president against the ABFO’s biggest critic? Haskell Pitluck.

“It was such an obvious conflict of interest, all I could do was laugh,” Bowers says. He and his attorney requested that Pitluck recuse himself and that the AAFS bring in a neutral arbiter. Pitluck refused. He then found probable cause for Loomis’s complaint. The AAFS would proceed with an ethics investigation of Bowers.

Loomis’s complaint alleges 13 ethical violations committed by Bowers over 13 years. But a close look at the accusations reveals them to be rather thin. For example, Loomis alleges that in the 2008 case California v. Frimpong, Bowers first claimed he could not exclude the defendant as the source of a bite mark, then, after the defense paid him, claimed he could exclude the defendant. Loomis is alleging that Bowers is a “hired gun” willing to change his mind in exchange for pay.

In his response, Bowers explains that his initial opinion was based on no more than a photo of a bite mark that he felt lacked enough detail to draw any conclusions at all. He wasn’t sent the dentition evidence taken from the defendant until the night before the trial. Because he didn’t have sufficient time to properly analyze the new evidence, he “could not exclude” the defendant as the source of the bite mark. Consequently, he didn’t testify. After the trial, Bowers had time to do a more thorough analysis with more evidence and came to the conclusion that the defendant could be excluded.

To say a defendant “can’t be excluded” is another way of saying that the available evidence doesn’t say much either way. It doesn’t indicate guilt, but it doesn’t exonerate either. Bowers explains in his response that he didn’t “change” his opinion; he went from “no opinion” to “having an opinion,” but only after he was presented with more evidence and given time to analyze it properly. This would seem to be exactly what we’d want from a conscientious expert witness.

Loomis also alleged an ethics violation because a judge once found Bowers’s testimony to be “not credible.” But this is hardly evidence of an ethical violation. In fact, because of the very subjectivity of bite mark evidence, these cases will often feature two expert witnesses offering two diametrically opposed opinions. During a bench trial or a hearing on admissibility of bite mark evidence, the judge will naturally have to rule for one side or the other. Judicial opinions aren’t scientific pronouncements, and in fact, as previously noted in this series, they’re often ignorant of or oblivious to the prevailing science. On many occasions, judges have vouched for the credibility of bite mark experts in upholding the convictions of defendants who were later proved innocent by DNA testing.

But even this is beside the point. Even if the judge had been correct about Bowers’s credibility, this sort of ruling isn’t proof — and doesn’t claim to be proof — that the expert who testified for the losing side was unethical. It really only means that he failed to persuade the judge. And as Fabricant points out, it also magnifies the selectivity of Loomis’s complaint: “You have two-dozen cases where a judge or a prosecutor found a bite mark analyst to be ‘credible,’ after which the suspect was completely exonerated of the crime. Some of these people spent decades in prison. Where are the ethics complaints against them? Michael Bowers helped exonerate many of those people. But he’s the one hit with a complaint, because a judge in one case didn’t find him credible? It’s just brazen.”

The most serious allegation in Loomis’s complaint is that Bowers altered or fabricated evidence in the Frimpong case. Loomis’s evidence for this charge is Bowers’s testimony during a hearing for the 2010 case Alabama v. Ramirez-Vitae. In that case, Bowers told the judge that in the Frimpong case he had reversed the orientation of the suspect’s teeth. Bowers’s testimony to the judge about why he did this is somewhat ambiguous, and Loomis’s complaint alleges that Bowers reversed the orientation in order to deceive. But to believe that, you’d have to believe that Bowers, a reputable expert witness with no prior allegations of ethical misconduct, not only deceptively and intentionally distorted evidence, but also openly boasted about doing so, directly to a judge, in a case two years later.

Bowers says he was open about what he was doing. He thought the state’s experts had the orientation wrong themselves — that they had mistaken the upper teeth for the lower teeth. And in fact, during post-conviction, one of the state’s own experts actually agreed with Bowers. The new expert, Greg Golden, disagreed with Bowers that when properly aligned, the marks excluded the defendant as a suspect. But he agreed with Bowers that the state’s expert at trial (a different analyst) had misaligned the teeth and the bite marks.

In other words, the prosecution offered up two ABFO-certified bite mark analysts as experts, one at trial and one during post-conviction. The analyst at trial said the bite marks implicated the defendant. During post-conviction, the second analyst analyzed the same bite marks, only with the upper and lower teeth of the defendant switched. But he, too, said they implicated the defendant.

Bowers says he brought the case up at the Alabama hearing because it illustrated the absurdity of the entire field of bite mark matching. “I told the judge in the Alabama case that this was an example of how ambiguous bite marks can be. How you can have multiple theories with multiple conflicting assumptions and opinions, but all of them within the ABFO guidelines,” Bowers says.

Obviously, an individual’s lower teeth are going to leave different marks than his or her upper teeth. One might think that the president of the organization that sets the standards for bite mark analysis would be concerned about the fact that two of its members implicated the same defendant despite the fact that their analyses were done with opposing orientations of the defendant’s teeth. Yet it’s Bowers that Loomis has targeted, for calling attention to the problem.

I asked Loomis about his complaint against Bowers in a phone interview last year. He said that AAFS bylaws prohibited him from discussing any ethics proceedings, so he could neither confirm nor deny the existence of any complaint. He also expressed concern about the fact that I had obtained a copy of his complaint and cautioned me about publishing it. Later in the conversation he added that if, in theory, he had filed a complaint against Bowers, anyone who read it would be thoroughly convinced of Bowers’s guilt.

“Dr. Bowers is not credible,” Loomis said. “I can’t confirm the existence of any complaint, but if there was one, and I could talk about it, I would change the minds of Bowers’ supporters.”

Loomis is right about the AAFS bylaws requiring confidentiality. But those bylaws are intended to protect the accused. Bowers stands as the accused and has asked for complete transparency. In his initial response to Loomis’s complaint, Bowers stated: “I waive all rights to confidentiality and hereby request a public hearing to adjudicate this matter . . . Moreover, I request the proceeding be videotaped, transcribed, and made available to the public.”

Pitluck eventually found probable cause for the complaint against Bowers to move forward. A hearing was scheduled for July 8, 2014, in a conference room at a Chicago hotel. By the time of the hearing, Pitluck’s term on the AAFS ethics committee had ended. He was replaced by Melson, a former federal prosecutor for 24 years who had most recently served as acting director of the federal Bureau of Alcohol, Tobacco, Firearms and Explosives. Melson was reassigned from his position in 2011 in the wake of the “Fast and Furious” scandal.

Despite the controversy surrounding his previous position, two forensics experts and advocates for forensics reform interviewed for this article say they considered Melson to be reputable and fair and initially considered him a good choice to chair the ethics committee. (Neither wished to be named.) In fact, Melson was also a president of AAFS in 2003-2004. In his “President’s Message” in the organization’s newsletter, he repeatedly emphasized the need for forensics reform, better certification and taking ethical obligations seriously.

When I first interviewed Risinger about the complaint last summer, he seemed confident that the AAFS would dismiss it. He said the organization had to treat the complaint seriously because there was a national spotlight on forensics at the moment. To disregard an ethics complaint — even one that appears to be retaliation against a whistleblower — would send the wrong message.

“In my opinion, the ethics complaint filed against Mr. Bowers is thin on its face, and without merit when viewed in the light of the responsive filing,” he said. “I know the AAFS is committed to being a reliable agency of self-regulation in forensic science, and, as in other contexts, that means not only reliably convicting the guilty, but also reliably acquitting the innocent. Under these circumstances, I believe their process will come to the right conclusion in this case.”

But Melson would surprise Risinger and other forensic watchdogs with an astonishing proceeding that fell far short of any reasonable conception of fairness or due process.

It actually began before the hearing, when according to Bowers, Melson turned down all of Bowers’s discovery requests. When the hearing was just a couple of months away, Bowers’s attorney Gabriel Fuentes wrote to Melson to complain that he he and his client still hadn’t been informed of what format the hearing would take, what evidence would be used against Bowers or who would be sitting in judgment of him. In fact, Fuentes wrote, Melson had turned over “absolutely no documents or information whatsoever.” From the time he first received notice of the complaint, Bowers had asked for an explanation of how each allegation against him violated AAFS ethical guidelines. Again, Melson refused. (Melson declined to be interviewed for this article, citing AAFS bylaws about confidentiality in ethics investigations.)

Fuentes was most concerned about Melson’s role in the hearing. In his letter, he complained that Melson had yet to make it clear whether he’d be acting as a prosecutor, as a representative of AAFS or as a judge in his position as chair of the ethics panel. The answer would turn out to be all three.

On the morning of the hearing, Bowers learned that Melson had actually met with Loomis the previous night. Not only that, but the purpose of the meeting was so that Melson could help Loomis prepare. Later, during the hearing, it was revealed that Loomis got the idea for the complaint after a conversation at a dinner party hosted by Golden —  the same analyst who agreed with Bowers about the proper orientation of the bite marks in Frimpong. Golden also preceded Loomis as ABFO president and now sits on the group’s executive committee. In addition, Loomis revealed that it was Golden who brought up the Frimpong case, the heart of Loomis’s complaint. (Golden was the opposing expert in that case.) None of this had previously been disclosed to Bowers.

Paula Brumit, also a member of the ABFO executive committee, was also one of the ethics committee members who was sitting in judgment of Bowers last July. Brumit had also met with Melson and Loomis the night before the hearing — also to help Loomis prepare his testimony. None of this was disclosed to Bowers or his attorney until the morning of the hearing.

“So two of the people on this supposedly unbiased committee, including the chairman, had met with my accuser the night before to help him prepare his case,” Bowers says. He adds, wryly, “And they’re aghast that anyone would dare suggest they’re on a witch hunt.”

The proceedings only got more absurd from there. Melson ran the hearing, acting as both judge and prosecutor. There are surreal passages in the transcript in which Bowers’s attorney objects to a question Melson asks as Melson is playing the role of prosecutor. At that point, Melson takes on the role of the “neutral fact-finder,” or judge, and overrules the objection. It also includes passages in which Melson the prosecutor objects to questions by Bowers’s attorney — then slips into the role of Melson the judge to sustain his own objections.

“It was a Star Chamber,” says Fabricant, who attended the hearing. “I’ve never seen anything like it. At every turn, they failed to afford Bowers even minimal due process. It was outrageous.”

On Sept. 6, Melson sent Fuentes a letter informing him that the committee had ruled against Bowers on one count. It had determined that Bowers had “committed a fraud on the court” in the Frimpong case. The ethics committee recommended that Bowers be expelled from AAFS. Melson told Fuentes that he would forward a copy of the committee’s report to the AAFS president and board of directors.

Under AAFS bylaws, Bowers is permitted to make his own appeal to the board. The problem is that Melson has refused to let Bowers see a copy of his committee’s report. In other words, Bowers is allowed to make an appeal, but he doesn’t get to see what exactly it is that he’s appealing.

Moreover, Melson didn’t specify on which of the allegations the committee ruled against Bowers. He still hasn’t. So Bowers must not only appeal without seeing the committee’s reasons for ruling against him, but he also must do so without knowing for certain exactly what the ethics committee thinks he did wrong. (Through the process of elimination, Bowers and his attorney are fairly certain that it’s the complaint alleging Bowers altered evidence in the Frimpong case.)

Brandon Garrett, a law professor at the University of Virginia who specializes in criminal procedure and innocence cases, reviewed the transcripts of the hearing and found them astounding. He submitted a declaration on Bowers’s behalf. In his declaration, Garrett wrote that the entire adjudicative process “failed to satisfy minimal, but fundamental, due process protections.”

The AAFS convenes for its annual conference this month in Orlando. During the conference, the AAFS board will consider the charge against Bowers. If the board votes to uphold it and expel him, Bowers can appeal and ask the entire AAFS membership to vote on the matter.

(Note: After the first of installment of this series ran on Feb. 13, the AAFS board voted on Monday to dismiss the charge against Bowers, against the recommendation of the ethics committee.)

After the ethics committee issued its recommendation, I spoke again with Risinger, the forensic evidence expert and law professor who initially seemed confident that Melson and his committee would do the right thing. He, too, was taken aback by what transpired during the hearing.

“Assuming that what I’ve heard about the hearing is correct, I was wrong to have as much faith as I did in the ethics process,” he said.

Tussles with the Bushes

By 2009, just as the ABFO was battling Bowers’s increasingly vocal criticisms and the fallout from the NAS report, the organization ran into another problem. In 2007 Mary and Peter Bush, a married couple who head up a team of researchers at the State University of New York at Buffalo, began a project to do what no one had done in the three decades — conduct tests to see whether there’s any scientific validity to the bite mark evidence presented in courts across the United States.

The Bushes sought to test the two main underlying premises of bite mark matching — that human dentition is unique and that human skin can record and preserve bite marks in a way that allows for analysts to reliably match the marks to a suspect’s teeth. The Bush team was the first to apply sophisticated statistical modeling to both questions. It was also the first to perform such tests using dental molds with human cadavers. Previous tests had used animal skins.

When they first set out on the project, the Bushes received preliminary support from some people in the bite mark analyst community. “Franklin Wright was the ABFO president at the time,” says Mary Bush. “He visited our lab, and then put up a message praising our work on the ABFO website.” They also received a small grant from the ASFO, the discipline’s non-accrediting advocacy and research organization.

“There was a lot enthusiasm at the outset,” says Fabricant. “I think some analysts were excited about the possibility of getting some scientific validation for their field.”

But when the Bushes began to come back with results that called the entire discipline into question, that support quickly dried up.

The Bushes’ research found no scientific basis for the premise that human dentition is unique. They also found no support for the premise that human skin is capable of recording and preserving bite marks in a useful way. The evidence all pointed to what critics such as Bowers had always suspected: Bite mark matching is entirely subjective. The Bushes’ first article appeared in the January 2009 issue of the Journal of Forensic Sciences. The couple have since published a dozen more, all in peer-reviewed journals.

Outside of ABFO and their supporters, the Bushes’ research has been lauded. “I think there’s a chance that because of the Bushes’ research, five years from now we aren’t going to be talking about bite mark evidence anymore,” says Risinger. “It’s that good. Their data is solid. Their methodology is solid. And it’s conclusive.”

Other legal scholars and experts on law and scientific evidence interviewed for this article shared Risinger’s praise for the Bushes’ research but were less optimistic about its implications, in part because the criminal justice system so far hasn’t recognized the significance of their work.

But from a scientific standpoint, the Bushes’ research was a direct and severe blow to the credibility of bite mark analysis. At least initially, it threatened to send the entire field the way of voice print matching and bullet lead analysis, both of which have now been discredited. And so when defense attorneys began asking the couple to testify in court, the bite mark analysts fought back with a nasty campaign to undermine the Bushes’ credibility. In a letter to the editor of the Journal of Forensic Sciences, seven bite mark specialists joined up to attack the Bushes in unusually harsh terms for a professional journal. When that letter was rejected for publication, five of the same analysts wrote another. That, too, was rejected. A toned-down but still cutting third letter was finally published.

In the unpublished letter dated November 2012, the authors — all bite mark analysts who hold or have held positions within ABFO — declared it “outrageous that any of these authors would go into courts of law and give sworn testimony citing this research as the basis for conclusions or opinions related to actual bite mark casework, especially considering that no independent research has validated or confirmed their methods or findings.”

Of course, critics would say this was a bit of rhetorical jujitsu — that the last clause could describe exactly what bite mark analysts have been doing for 35 years. For emphasis they added, “This violates important principles of both science and justice.” In the other letter, the authors referred to the Bushes’ testimony in an Ohio case, which was based upon their research, as “influenced by bias” and “reprehensible and inexcusable.”

The primary criticism of the Bushes’ research is that they used vice clamps to make direct bites into cadavers that were stationary through the entire process. This is quite a different scenario than the way a bite would be administered during an attack. During an assault, the victim would probably be pulling away, causing the teeth to drag across the skin. For the Bush tests, the clamp they used to make the bites moved only up and down. A human jaw also moves side to side. A biter might also twist his head or grind his teeth. A live body will also fight the bite at the source to prevent infection, causing bruising, clotting and various other defenses that would alter the appearance of the bite.

“We acknowledge that our lab tests are different from how bites are made in the real world,” says Mary Bush. “But to the extent that our tests differed, they should have made for better preserved samples.”

In other words, the tests that the Bushes conducted made for cleaner, clearer bites that could be easily analyzed. If they were in error, they were in error to the benefit of the claims of bite mark analysts. And they still found no evidence to support the field’s two basic principles.

“That’s exactly right,” says Risinger. “If there was any validity to bite mark analysis at all, these tests would have found it. They gave the field the benefit of the doubt. The evidence just wasn’t there. Their data is very, very strong.”

To argue that the Bushes’ experiments should be disregarded because they weren’t able to replicate real-world bites is also an implicit acknowledgment that real-world bites aren’t replicable in a lab, and therefore aren’t testable. You won’t find many people volunteering to allow someone else to violently bite them for the purposes of lab research. Even if you could, a volunteer won’t react the same way to a bite that an unwitting recipient might.

The Bushes’ research not only failed to find any scientific support for bite mark matching, but it also exposed the fact that for four decades the bite mark community neglected to conduct or pursue any testing of its own. It put the ABFO and its members on the defensive. The bite mark analysts responded by intensifying their attacks on the couple and making the attacks more personal.

At the February 2014 AAFS conference in Seattle, the ABFO hosted a dinner for its members. The keynote speaker was Melissa Mourges, an assistant district attorney in Manhattan, one of the most outspoken defenders of bite mark matching in law enforcement.

Mourges already had a high profile. The combative, media-savvy prosecutor was part of the prosecution team featured in the HBO documentary “Sex Crimes Unit,” which followed the similarly named section of the Manhattan DA’s office, the oldest of its kind in the country. Mourges herself founded a cold-case team within that unit. At the 2012 AAFS conference she spoke on a panel called “How to Write Bestselling Novels and Screenplays in Your Spare Time: Tips From the Pros.” At this year’s conference, she’ll be on a panel that’s titled “Bitemarks From the Emergency Room to the Courtroom: The Importance of the Expert in Forensic Odontology.” She’ll be co-presenting with Franklin Wright, the former ABFO president who initially supported the Bushes’ research.

Mourges was also the lead prosecutor in State v. Dean, a New York City murder case in which the defense challenged the validity of the state’s bite mark testimony. In 2013, Manhattan state Supreme Court Judge Maxwell Wiley held a hearing on the scientific validity of bite mark evidence. Mary Bush testified about the couple’s research for the defense. It was the first (and so far the only) such hearing since the NAS report was released, and both sides of the bite mark debate watched with anticipation. In September 2014, Wiley ruled for the prosecution, once again allowing bite mark evidence to be used at trial. (I’ll have more on the Dean case in part four of the series.) Mourges’s talk at the ABFO dinner was basically a victory lap.

There’s no transcript of Mourges’s speech, but those in attendance say it was basically a no-holds-barred attack on Mary Bush. Cynthia Brzozowski has been practicing dentistry in Long Island for 28 years and sits on the ABFO Board of Directors. She practices the widely accepted form of forensic dentistry that uses dental records to identify human remains, but she doesn’t do bite mark matching, and she won’t testify in bite mark cases. Brzozowski was at the dinner in Seattle and says she still can’t believe what she heard from Mourges.

“Her tone was demeaning,” Brzozowski says. “It would be one thing if she had just come out and presented the facts of the case, but this was personal vitriol against the Bushes because of their research.”

According to Brzozowski, Mourges even went after Mary Bush’s physical appearance. “At one point, she put up an unflattering photo of Mary Bush on the overhead. I don’t know where she got it, or if it had been altered. Mary Bush is not an unattractive person. But it was unnecessary. You could hear gasps in the audience. It was clear that she had chosen the least flattering image she could find. Then she said, ‘And she looks better here than she does in person.’ It was mean. I had to turn my back. I was mortified.”

Other ABFO members — including two other members of the board of directors — also complained, to both the ABFO and the AAFS. The complainants described Mourges’s attack on Bush as “malicious,” “bullying” and “degrading.” According to accounts of those in attendance, other members were also upset by Mourges’s remarks but didn’t file formal complaints for fear of professional retaliation.

A few weeks later, Loomis sent an e-mail to the ABFO Board of Directors to address the complaints. Loomis defended Mourges and her presentation. He described the dinner as a “convivial affair” where members can socialize, have a libation and “be entertained” by the invited speaker. He argued that “anyone who understands litigation” should not have been unsettled by the talk and described the presentation as “sarcastic, serious, and even light-hearted.” He stood by the decision of his predecessor, Greg Golden, to invite Mourges, calling it “a good decision,” adding, “I apologize to those who were offended. However, I do not apologize for the message.”

“‘Bullying’ is exactly what it is,” says Peter Bush. “We’re scientists. We’re used to collegial disagreement. But we had no idea our research would inspire this kind of anger.”

Loomis had good reason to know exactly what he’d be getting in Mourges. At the previous AAFS conference in Washington, D.C., Mourges heckled the Bushes during a panel in which they tried to explain their research. According to those in attendance, she brought a printout of Mary Bush’s testimony from the Dean case and essentially tried to continue her cross-examination in a public forum.

Even in her brief in the Dean case, Mourges went well beyond standard legal arguments to launch personal attacks at the critics of bite mark matching. At one point in the brief, she implies that Bowers is cut from the same cloth as the notorious bite mark charlatan Michael West. She notes that both have resigned from the ABFO and that she finds it “a relief” that neither plans to testify in court again. (Note: Bowers says he doesn’t know where Mourges got this — he’s still testifying presently and plans to do so in the future.) She also references Bowers’s testimony in the Frimpong case, falsely stating that he “admitted publicly and under oath that he manipulated evidence,” a good indication that the attacks on Bowers and the Bushes have been well coordinated.

Mourges’s attempt to conflate the most notorious fraud in the annals of bite mark analysis with a man who has spent the past two decades trying to expose the field’s shortcomings is certainly audacious. Multiple advocates for forensics reform said it’s also completely unmoored from reality.

“It’s patently absurd,” says the Innocence Project’s Fabricant. “Michael Bowers is well-regarded and well-respected. His work was cited in the NAS report. To my knowledge, the only people who have ever questioned his ethics are the people he’s been trying to expose.”

(The Manhattan DA’s office did not respond to my requests to interview Mourges for this series.)

This is the way it has been for critics of bite mark matching. Despite the trail of innocents put behind bars — some of whom were nearly executed — it’s the critics who have been put on the defensive. They’re heckled and belittled at forensics conferences, are subjected to lawsuits and ethics complaints, are attacked in court briefs and can expect their professional reputations to be called into question.

Ian Pretty testified for Bowers at the AAFS hearing. Pretty is a professor of public health dentistry at the University of Manchester in the United Kingdom. He’s somewhat critical of bite mark matching but less vocal about his objections than someone like Bowers. He also chairs the AAFS odontology section. At the hearing, Pretty alluded to the treatment of Bowers and the Bushes and said he feared that the attacks on them would chill critics and stifle an open debate.

“One thing that I have noticed and I’ve become increasingly concerned about is the tone in which . . . certain [individuals’] research has been received,” Pretty said. “I’ve found that the discourse around our scientific sessions has become more aggressive than I would like to have seen.” He added that “there’s been somewhat of an attack on the ability for people to speak freely. ” He also worried that the hearing would create a new method of attacking critics through the ethics process, “that we will have situations where people are concerned about what they say, be it in court, be it in depositions, be it in an Academy meeting, [they’ll] fear that they will be brought in front of this Ethics Committee for expressing an opinion.”

“We were naive going into it all,” says Mary Bush. “We thought we were providing research that would help prevent innocent people from getting convicted. We expected disagreement, but we expected polite, academic disagreement. We never expected the response to be so vitriolic.”

That vitriol has been persistent. In June 2013, Fabricant moderated a panel on forensics at a New York City conference hosted by the American Bar Association. Mary and Peter Bush were on the panel. During the question-and-answer period, the Bushes were once again subjected to some pointed criticism from a member of the audience. He derided the Bushes’ research and defended bite mark matching.

That audience member was Ira Titunik. The following month, DNA testing exonerated Gerard Richardson, the man Titunik’s bite mark testimony had put in prison for 20 years.

Addendum: After this post was published, the office of Manhattan District Attorney Cyrus Vance sent the following statement:

Melissa Mourges is a veteran prosecutor and a nationally recognized leader in her field. As Chief of the Manhattan District Attorney’s Forensic Science/Cold Case Unit, she has solved dozens of cold case homicides, including two recently attributed to “Dating Game” serial killer Rodney Alcala. In addition to being a Fellow at the American Academy of Forensic Sciences, ADA Mourges has also served as co-chief of the DNA Cold Case Project, which uses DNA technology to investigate and prosecute unsolved sexual assaults. As part of that work, she pioneered the use of John Doe indictments to stop the clock on statutes of limitation and bring decades-old sexual assaults to trial. Her work and reputation are impeccable, and her record speaks for itself.