The Washington PostDemocracy Dies in Darkness

Opinion More overturned convictions, more scrutiny for bite mark analysis

There have been a number of new developments since we last visited the issue of bite mark analysis.

First, another person convicted with bite mark evidence has been freed from prison, at least for now. From my Washington Post colleague Sarah Kaplan:

Steven Mark Chaney sat in a Texas courtroom with the rest of his life on the line and listened as a forensic dentist told jurors it was his teeth that caused bite marks on the arm of a dead drug dealer named John Sweek.
“One in a million,” was the phrase the dentist, Jim Hales, used. There was a one-in-a-million chance that the marks could have come from anyone else.
Prosecutors said that the marks were proof that Chaney had killed Sweek and his wife, Sally. And the jury seemed to agree. Despite testimony from nine witnesses who said they saw him elsewhere, Chaney was convicted of murder and sentenced to life in prison. One juror even said after the trial that it was the bite mark testimony that convinced her, the Associated Press reported.
That was in 1989. Now, after Chaney has spent more than a quarter of a century in prison, he’s been freed by a Texas state court judge. The intervening years have shown that there is little scientific basis for the supposedly conclusive bite mark analysis, and Hale’s “one in a million” claim was just an expression, not a statistic.
In an affidavit filed Friday, even the dentist whose testimony helped convict Chaney said that his conclusion was “scientifically unsound.” And, according to advocates and national researchers, it’s not the only type of testimony with that problem.
Chaney isn’t necessarily not guilty, but the evidence that he was guilty was deeply flawed, according to lawyers, advocates and the Dallas County District Attorney. While an appeals court reviews his case, Chaney will be free for the first time in 28 years. He is 59.

Notably, the other state expert witness who testified against Chaney was a now-deceased bite mark analyst named Homer Campbell. More on him in a minute. But Chaney’s wasn’t even the only case this month.

A judge on Thursday overturned a woman’s murder conviction and prison sentence after a bite mark expert who testified against her at trial said he now believes his findings were “junk science.”
Fayette County Judge John Wagner ruled in the case of 38-year-old Crystal Dawn Weimer, of Connellsville, after a brief hearing about 40 miles south of Pittsburgh. Weimer has repeatedly insisted she’s innocent in the 2001 beating death of 21-year-old Curtis Haith.
She was convicted of third-degree murder in 2006 and sentenced to 15 to 30 years in prison. A man imprisoned in the case had testified that Weimer helped lure Haith to the scene. A dental expert, Dr. Constantine Karazulas, testified that a bite on the victim’s hand matched Weimer.
But the witness who placed Weimer at the scene has since recanted, and the dentist changed his mind, too.

I suppose it’s great that these “expert” witnesses are recanting their testimony. But as I’ve written here before, we’ve entrusted judges to be the gatekeepers of scientific evidence. That evidence this transparently ridiculous was even admitted in these cases — not to mention hundreds of others, and not to mention the thousands of other cases tainted by bogus or overstated forensic analysis — is a pretty good indication that putting judges in charge of sorting good science from bad has been disastrous.

The other major development takes us back to Texas, where the state’s Forensic Science Commission has now turned its sights on bite mark evidence. The commission was formed in the wake of the growing evidence that the state executed an innocent man, Cameron Todd Willingham, after convicting him with arson science now widely recognized as fraudulent.

I’d suggest that the commission take a hard look at the case of David Wayne Spence, who was executed in 1997 for his alleged role in the 1982 Lake Waco murders. Spence was convicted primarily based on testimony from … Homer Campbell.

Campbell made some really absurd claims over the course of his career. In fact, just two months after Spence was convicted, Campbell identified the remains of a body found along a roadside as that of a missing Florida teen. He did this by matching the corpse’s teeth to a photo of the teeth of the missing girl. His conclusion was later, er, called into question when the missing girl turned up … alive. Bizarrely, about a year after the Lake Waco murders, Spence’s mother was raped and murdered. Campbell was the expert witness in that case, too. He claimed to have found bite marks on the victim that he could match to a man named Joe Sydney Williams. Because of Campbell’s testimony, Williams and his friend Calvin Washington were convicted in 1987. In 2007, a journalist found DNA samples from the rape kit that were thought to have been lost. Testing on those samples exonerated both Williams and Washington. They were released from prison.

In upholding Spence’s conviction in 1996, federal judge Edith Jones explicitly referred to Campbell’s testimony.

. . .the State’s forensic odontological expert concluded that the bite marks on Jill’s and Raylene’s bodies were inflicted by Spence. Even Spence’s rebuttal expert in this field could not rule out the possibility that Spence’s teeth caused the wounds, although he believed there was too little evidence to support a firm conclusion.
. . . Spence’s argument that Dr. Campbell had misidentified the remains of another woman likewise does not expose his testimony against Spence as false.
Spence is simply trying to relitigate this aspect of his defense eleven years too late. At trial, Spence introduced his own forensic odontologist, Dr. Gerald Vale, a leading expert in the field. Dr. Vale spiritedly criticized Dr. Campbell’s methodology and conclusions, although, critically, Dr. Vale admitted he could not rule out Spence’s teeth as the source of the bite marks. Because this evidentiary issue was fully and competently aired in the state courts, no violation of fundamental fairness under the due process clause has been shown.

Campbell should never have been allowed to testify in the first place. If Vale was claiming that bite mark analysis is scientifically valid, he shouldn’t have been allowed to testify either. But an honest and competent forensic witness would have testified, just as Vale did, that he or she could not rule out Spence as the source of bite marks, because except in some very limited circumstances (i.e. the defendant has no teeth), there’s simply no scientific research supporting the notion that you can definitely make conclusions about one person’s dentition and a bite mark found in skin — whether it’s to implicate that person or to exclude him.

The commission’s review of bite mark evidence has also caused some interesting developments at the American Board of Forensic Odontology (ABFO), the main advocacy group for bite mark analysts. The ABFO still maintains that bite mark analysis is a valid science even though, as first reported here at The Watch, a proficiency test that the group recently administered to its own members showed wide disagreement about whether photos of marks in human skin depicted human bite marks. (If bite mark matching were a real science, you wouldn’t see such disagreement over such a fundamental question.) More damning still, the disagreement was strongest among the most experienced members of the organization. The ABFO then tried to keep the results of that test from going public. (In an e-mail, ABFO president Gary Berman says the study only showed that there are flaws in the terminology that the ABFO uses for identifying bite marks and that the organization is addressing this problem.)

One of the two people who designed and administered that proficiency test is Adam Freeman, a longtime bite mark analyst and who until recently was the chair of the organization’s Bitemark Committee. The Bitemark Committee. Freeman resigned from that position last month. Curiouser still, ABFO president Gary Berman appointed dentist and bite mark analysis proselytizer Roger Metcalf as Freeman’s replacement. Under ABFO bylaws, new committee chairs must be voted on by the group’s board of directors. Berman appointed Metcalf without notifying the board. This is significant because both the ABFO board and the general membership include members who are skeptical of bite mark matching. I’ve learned that many of the skeptics were not copied on Berman’s e-mail announcing Freeman’s resignation and the appointment of Metcalf as his replacement.

Berman writes over e-mail that, “Some of the chair persons need to be approved by our board of directors, other do not.  I forgot that the Bitemark Committee Chair was one of those needing a vote, and when I was informed, I immediately requested a vote and approval of the new Bitemark Chair Dr. Metcalf. He was approved by the ABFO Board of Directors.”

As for why critics of bite mark matching within the organization weren’t copied on the e-mail announcing Metcalf’s appointment, Berman writes, “If there has been any missed communications, I alone am responsible. It was not intentional. This was not a deceptive tactic by me. Those ABFO diplomates that have been critical of the current bitemark analysis guidelines are vital to our organization.”

Berman also appointed other new members to the Bite Mark Committee. One of the new appointees is Ira Titunik, a dentist in New York City. As I reported in my series on bite mark evidence last February, it was Titunik’s testimony that convicted Gerard Richardson for the 1995 murder of Monica Reyes in Bernards Township, N.J. Titunik has since become a vocal evangelist for bite mark analysis. At a conference in 2013, Titunik publicly challenged Mary and Peter Bush, scientists whose research has cast doubt on some of the fundamental presumptions necessary for bite mark matching to work — that human dentition is unique and that human skin is capable of preserving bite marks in a useful way. Their work subjected them to a campaign of public harassment and denunciations from ABFO members and their allies. One month after Titunik challenged the Bushes at that conference, DNA testing on the rape kit taken from Monica Reyes excluded Gerard Richardson as her rapist.

Berman says that Titunik’s appointment was not strategic, but rather the result of a policy under which the organization allows any member to serve on any committee he or she requests.

But the ABFO has claimed that the cases in which innocent people were convicted because of bite mark evidence were the work of rogue analysts who used methods no longer approved by the organization. That claim is hard to take at face value given that with one exception, the organization has never criticized any of these rogue analysts by name, much less stripped them of their certification. The organization has also publicly criticized, launched personal attacks against, and filed ethics complaints against those who have questioned the methods that led to those wrongful convictions. In a letter to the Texas Forensic Science Commission last month, ABFO president Berman also addressed wrongful convictions:

The ABFO is acutely aware of cases involving bitemark analysis in the past that have contributed to several individuals being wrongly convicted. This is not acceptable. The ABFO has continuously updated and improved its recommendations for appropriate investigation, evidence collection procedures and methods of bitemark analysis and will continue to do so.

Berman added that the ABFO Bitemark Committee would be the arm of the organization handling the commission’s questions. Yet he wrote the passage above at the same time he was appointing to that committee a dentist whose testimony helped convict a man who was finally released less than two years ago.

A dentist named Greg Golden will also serve on the Bitemark Committee. Golden is a former ABFO president and helped past president Peter Loomis formulate the ethics complaint the organization filed with the American Association of Forensic Sciences against longtime bite mark analysis critic Michael Bowers. (Berman insists that the complaint against Bowers was Loomis’s action alone, but it was revealed during Bowers’s hearing that the idea was hatched at a dinner party hosted by Golden, and that it was Golden who mentioned the case that ultimately served as the backbone of the complaint.) It was also Golden who invited Manhattan prosecutor Melissa Mourges to give a keynote address in which she launched into a nasty personal attack on Mary and Peter Bush.

In his e-mail to me, Berman insisted that, “[W]e will request of our membership that anyone having been involved in any Texas bitemark comparison case in court to please notify the Texas Forensic Science Commission Bitemark Review Panel directly with this information.”

Yet internally, the ABFO leadership appears to be sending a different message. I’ve obtained an internal e-mail from Berman to the ABFO membership that included comments from Roger Metcalf, the new chair of the Bitemark Committee about the first meeting of the Texas Forensic Science Commission. I’m publishing Metcalf’s comments here, because I think they’re illuminating.

Dear All: Well, the Texas Forensic Science Commission had its first bitemark panel meeting today in Dallas, as you all know. We were very fortunate to have ABFO members Bob Williams, Paula Brumit, and David Senn present–as well as yours truly. The meeting, in my opinion, went better than I had feared it would go, though I don’t know if the other ABFO’s necessarily agree with that assessment or not.
In any case, it seems to me that we ABFO’s thought this was going to be more-or-less an organizational meeting, but the panel did hear an impromptu presentation from Chris Fabricant (from the Innocence Project) regarding his view of the “deplorable current state” of bitemark practice.
David Senn then did a remarkable and incredible job in an off-the-cuff presentation to the panel as well, and I think the panel really realized that they had been receiving a very one-sided take on things from the I.P. I think the panel thought we were going to come in fighting tooth and nail, but David told them that we certainly do recognize there have been some “bitemark cases gone bad” and that we do need to embrace the “Freeman/Pretty study” and that there is some valuable information there for us to use. We have learned and we have grown and evolved, We tried to get across the point that we have taken to heart all those things from old cases, and the way we do bitemark analyses now is NOT the way that analyses were done “back in the day….” Again, David, did an outstanding job with essentially no preparation, and we should all thank him very much, IMHO.
It appears to me that the panel Chair, Dr Harvey Kessler (an oral pathologist), is going to be pretty fair and even-handed, at least I hope so. The final make-up of the panel is still not set at this point–there will be some more folks added….in fact, the Commission will be sending a request to the ABFO to nominate a certain number of folks from which the Commission will select a few more members.
I think the reason this is very important to the ABFO is that the Texas Forensic Science Commission has been viewed, rightly or wrongly, by other states as a model for what their own Commissions should do. So it’s the old “domino theory” at work here for us–if bitemark analysis goes down in Texas, then other states may well follow, too…. But I think we’re going to get a better shot at defending ourselves in this than I was afraid we would previously…in any case, as it turns out, the Commission does not really have authority to do much besides investigate bitemark cases and issue some recommendations–and it seems they are going to have a fairly difficult time in identifying all the bitemark cases that they may want to investigate…..they apparently hope that odontologists will voluntarily disclose to the panel a list of all their cases….ummm….yeah, maybe, maybe not…..

There’s lots going on here, but let’s start with that last paragraph. Externally, ABFO president Berman is promising the Texas Forensic Science Commission that the ABFO is serious about reform, adamant about stamping out wrongful convictions and ready to cooperate in any way it can. Internally, Metcalf is ridiculing the notion that ABFO members would cooperate with the commission in identifying cases in which its members have testified, implicitly conceding that doing so would be bad for bite mark analysis.

More broadly, it’s interesting how Metcalf paints the bite mark community as the voice of caution, reason and moderation. He acknowledges that bite mark analysis has a questionable history. But it is he and other ABFO members who have viciously attacked critics like Bowers and the Bushes, critics who have been trying for years to sound the alarm about what was happening “back in the day.”

If Metcalf and other defenders of bite mark analysis concede that bite mark analysis in the past helped contribute to wrongful convictions, they should be hard at work to produce a list of cases as soon as possible. It’s possible, perhaps even likely, that there are other wrongful convictions yet to be discovered.

But, of course, that sort of review could prove embarrassing. The discovery of more wrongful convictions would cast further doubt on bite mark analysis. It may even subject some current ABFO members to (additional) lawsuits. And some of the analysts involved in those convictions may make it yet more difficult for the community of bite mark analysts to separate itself from its past. (Though critics would say that the group’s present positions are no more defensible.)

Say, for example, that the commission did look into the case of David Wayne Spence and finds that he was wrongly convicted and executed. Homer Campbell (now deceased) wasn’t just a champion of bite mark analysis; he wrote some of the early guidelines for bite mark matching and served as president of the American Academy of Forensic Sciences. Neither the ABFO nor the AAFS ever sanctioned Campbell, nor did either organization make any attempt to distance themselves from him. As recently as 2011, Campbell was posthumously given the Lester Luntz Award by the odontology section of the AAFS, named after one of the pioneers of bite mark matching. This was well after Campbell’s history of preposterous testimony and responsibility for two wrongful convictions were well known.

Metcalf is right about one thing. The commission at most can only issue recommendations. So far, bite mark evidence has come under fire from the National Academy of Sciences, a senior science adviser to the White House, two federal judges, editorial boards and a number of science organizations and forensic watchdogs. Yet to date, not a single state court has ruled it inadmissible in criminal trials.