Bitemark Analysis Not Recommended for Funding in U.S. Senate Hearing on Forensic Science

By David Averill

The United States Senate heard testimony from a distinguished panel last Wednesday on Capitol Hill. When asked by Senator Nelson which forensic discipline should not be advanced, Mr Mearns, the Co-chair, National Academies’ Committee on Identifying the Needs of the Forensic Science Community said that in his opinion, forensic odontology (bitemarks) is so far from scientific validation that it is not worthy of research funding. See the video clip below for his exact words.

This testimony was from a hearing of the United States Senate Committee on Commerce, Science and Transportation that is investigating the science of forensics. The hearing was held on Wednesday, December 7th on Capitol Hill. Senator Jay Rockefeller is the chair of the committee which included testimony from John Grisham, Innocence Project, Charlottesville, Virginia; Constantine Gatsonis, Brown University, Providence, Rhode Island; Geoffrey S. Means, Cleveland State University, Cleveland, Ohio; and Terry W. Fenger, Marshall University Forensic Science Center, Huntington, West Virginia. Dr. Gatosonis and Mr. Means were the co-chairs of the National Academy of Science committee that produced the report in 2009 for congress called “Strengthening Forensic Science, a Pathway Forward”.

The complete web archive of the video can be found here.

Senator Rockefeller in his pre-testimony opening remarks was critical of the forensic science community, not the practitioners. He feels that the problem involves the “science”, partly because there are no national standards for the language used in the courtroom to report outcomes. He gave an example of when an expert in a fancy suit and fancy degrees says the evidence is a “match” the next place for the defendant is a jail cell.

Forensic Odontology also suffers from this lack of standard meanings for the terms used to identify bitemarks and the lack of error rates associated with the terms used. The ABFO further obfuscates the use of terminology last year by adding the term “cannot exclude” to the opinions approved to be expressed in bitemark analysis terminology. Juries, law enforcement, prosecutors, and judges don’t know or understand what the term “can’t exclude” actually means.

As a case in point, ”can’t exclude” was used by a forensic odontologist in a preliminary hearing this fall in Washington, D.C.. The bitemark had low or no forensic value but was put forth by the prosecution as bitemark evidence in the homicide case. What the expert did to “help” the prosecution was a lengthy report full of measurements, color photographs and fancy diagrams relating the bitemark to the defendant with a final conclusion of “can’t exclude”. In reality, this bitemark had no forensic identification value with probably 99% of the population capable of making the markings. This information is not however provided to the court. The prosecutor decided not to present the bitemark evidence because of “other problems” that cropped up in the case which will be a blog post in the future.

The future of un-validated forensic science may be in the hands of Congress.


Bitemark Certification Board Objects to Defense Subpoena Demanding Release of Expert Opinions

By Dr. Michael Bowers

Recently, in the District of Columbia Superior Court, the forensic organization that certifies bitemark analysis made a failed attempt to suppress expert opinion in a bitemark case. The case in point is US v Ridley, a recently tried murder case involving a human bitemark on the deceased victim. Preceding the trial, there was oral argument over the admissibility of expert reports unfavorable to the District’s prosecution theory of the defendant’s guilt.

The prosecution’s expert, who is an ABFO certified forensic dentist, used the photographs of the victim’s bitemark and the defendant’s dental models as the bitemark testing material for the 2011 ABFO certification exam. That’s a error because the case had not been tried, nor a verdict determined at the time of the ABFO exam. The legal crux of this matter is simple. Each board certification applicant who took the ABFO exam completed a detailed analysis of the Ridley evidence, wrote extensive reports for the ABFO testing committee, and gave oral presentation of their findings. The defense counsel argued in court its legal right to see these reports. A subpoena for these heretofore-unknown reports was submitted by the defense and placed before the judge. The prosecution objected and a hearing was then held, which is the source of this post’s information.

The prosecutor in this case who responded to the subpoena, spoke to the judge and represented the prosecution’s and the ABFO’s objections to the release of these reports. Evidently the reports submitted for board certification were contrary to the prosecutions expert. In a real science if the prosecution’s dental expert made a mistake and published the bitemark evidence (only photos and dental models; no other documentation from the case were included and teeth models of a second fictitious suspect were included for the exam), then the forensic group should admit to the error and agree to the legal right of the court and the defendant to examine the additional reports written by board eligible dentists, who are all now board certified dentists.

The judge heard both sides, and in telephone testimony from the prosecutor’s expert confirmed that these extra judicial reports existed. In a surprise revelation, most or all of the reports did not concur with either the prosecutorial dentist’s opinion or the reports from the two additional dentists who rendered second opinions on the behalf of the prosecution’s dentist. Subsequent to these revelations, the judge granted the subpoena and ordered the ABFO to produce all reports and materials germane of the four applicants.

In a communication to the defense counsel in a last ditch effort to minimize the impact of the findings, the two past ABFO presidents who were tasked with obtaining and divulging the exam reports and evidence, commiserated once more on their objections to the subpoena. Their reasoning, in part, is this statement:

The candidates were required to show how their opinions were formed and evaluated on their ability to present the facts of the constructed case, communicate and demonstrate their analysis methods, and defend their conclusions.

Again, this was a created and fictitious case scenario. No “right” or”wrong” conclusions existed. The candidates were not graded on the absolute “correctness” of their opinions but rather on the processes they utilized to reach those conclusions.

There was no intent or attempt to make this examination scenario identical or similar to any existing actual casework.

Understanding actual bitemark cases and the use of limited information about a patterned injury in skin as a board examination are vastly different. Thus, it is not appropriate to compare the two processes.

Now, am I missing something here? The physical evidence materials for the ABFO bitemark exam were taken from an actual case that had not been tried yet. The use of a case’s extraneous documentation and circumstantial information should be withheld from a forensic examiner (fingerprint, firearms, DNA to name a few) until after the physical analysis is complete. Yet the ABFO appears to differ with this protocol and clearly state that all this extra information is necessary to render a final opinion on the analysis of physical evidence. Therefore, the ABFO bitemark exam is not representative of actual casework or the practice of bitemark identification.

How vastly different is forming an opinion on limited information on a patterned injury in skin from forming an opinion in an actual case? This was material from an actual case. If it is not appropriate to compare the processes, then what benefit does the ABFO applicant gain by completing the examination? If all that is important is following a process to form an opinion, and the correctness of the answer is unimportant, then what value is ABFO certification for the trier of fact?

Does the Forensic Science Advisory Board of the American Academy of Forensic Science know about this? This is the parent organization that certifies the ABFO. I t certainly should, because one of the ABFO past presidents who wrote the above quote is Secretary of the FSAB. The FSAB might also like to know that the results of the examination were destroyed, against the standards of the FSAB.

So the much embattled American Board of Forensic Odontology (ABFO), continues its uphill fight to preserve its courtroom credibility by offering direct support for the continued prosecutorial use of their Congressionally debunked and scientifically untested bitemark comparison opinions. The ABFO continues to orchestrate its membership down the unacceptable path of prosecutorial partisanship.

Judges growing critical of ‘CSI’ evidence

Judges growing critical of ‘CSI’ evidence

By Dan Vergano, USA TODAY

The CSI: Crime Scene Investigation series makes it look easy, but forensic science doesn’t always do so well in the courtroom with judges. And a pair of upcoming studies in the Journal of Forensic Science suggests some judges’ suspicions are growing about the shakier types of scientific evidence.

In the studies led by Mark Page of Australia’s University of Newcastle, legal experts looked at U.S. cases since the 1993 Daubert v. Merrell Dow Pharmaceuticals Inc. and 1999 Kumho Tire Co. Ltd. v. Carmichael court decisions that set higher standards for scientific evidence in criminal cases. Previously, past use of a technique, such as fingerprints or ballistics, had been sufficient to allow their use in the courtroom. But the Daubert and Kumho decisions had allowed defense attorneys to challenge the reliability of the techniques and the experts championing them, on scientific grounds:

“After Daubert and Kumho, many scholars assumed that a large proportion of forensic evidence presented in criminal and civil courts across the country would now be subject to renewed judicial scrutiny. However, some quickly realized that the real question was not whether legal academics concerned with the reliability of forensic science could interpret Daubert to justify the results they desired, but whether judges would do the same. Studies on the admissibility of forensic science since the Daubert decision have revealed that courts across the United States have felt its influence, even in those jurisdictions that have not explicitly adopted a Daubert standard. Several authors have noted that ”some forensic sciences have been with us so long, and judges have developed such faith in them, that they are admitted even if they do fail to meet minimal standards under Daubert”. The courts thus still appear extremely reluctant to deny the admission of forensic science evidence testimony in both civil and criminal trials. The legal reasoning by which forensic science evidence is admitted, characterized by some as ”judicial gymnastics,” has also been the subject of much criticism,” says the first study.

In addition, scandals at police crime labs and a critical 2009 National Research Council report have also called forensic science (aside from DNA analysis) into question. So, the studies look at how judges are sizing up scientific evidence. The bottom line is that some are growing skeptical, but probably not enough.

In the first analysis, the team looked at 551 cases from 1991 to 2008 where defense lawyers challenged forensic evidence, particularly the 81 cases where judges threw out some or all of it. The leading cause of exclusion was the lack of reliability (36%) for techniques such as document analysis followed by (24%) expert witnesses making inappropriate statements. Says the study, “it is clear that there is a sizable proportion of forensic identification evidence that is failing to meet evidentiary standards in U.S. courts. It is also apparent that in such cases, the reliability of forensic identification science evidence, encompassing the concerns regarding the discipline’s underlying theory, the expert’s testimony, and their methodology, accounts for the majority of judges’ concerns regarding its admission.”

In the second report, the team looked at the reasons for those exclusions, findin that poor casework and unreliable techniques are increasingly chipping away at judge’s acceptance of some standard kinds of forensic evidence, such as custom experiments by experts or handwriting analysis. “Reliance on general acceptance is becoming insufficient as proof of the admissibility of forensic evidence. The citation of unfounded statistics, error rates and certainties, a failure to document the analytical process or follow standardized procedures, and the existence of observe bias represent some of the concerns that have lead to the exclusion or limitation of forensic identification evidence,” concludes the study.
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The inane responses of dentists who describe themselves as “skin-reading” experts

This is a guest post by Dr. Michael Bowers

The non-scientific dental discipline known as bitemark analysis has only a few dogmatists left, who deny its well-known status as a forensic train wreck and cling to decades old assumptions that judicial admission of their baseless opinions is a substitute for validation and reliability proofs. The downward slide of forensic dentists who tout themselves as “readers” of skin injuries caused by human teeth has been occurring for the last ten years through criticism from legal academics (Saks 1999, Gianelli 2009, Beecher-Monas 2009, Deitch, 2010; and a small cadre of sagacious forensic dentists; Rothwell 1999; Sweet, Pretty 2001, Pretty 2010; Clements 2010. This slip from glory has also been assisted by a string (N>12) of DNA fueled exonerations overturning erroneous convictions originally helped by the opinions of highly credentialed members of the American Board of Forensic Odontology. Finally, within the last four years, bitemark experts have been challenged as bitemark “readers” by the independent and compelling research from the University of Buffalo (mentioned here in previous blogs on denoting human skin’s inability to accurately record tooth marks and questioning the uniqueness of the human front teeth. Taken together, the undeniable exonerations and current research results point to the fact that serious questions must be raised about the astonishing opinions that are being made concerning the very poor pattern impression evidence that constitutes bitemark evidence.

In response to the above, the forensic double-speak currently in vogue by the ABFO and its sub group of bitemark devotees is worthy of description. Just think of the analogy of Copernicus versus Galileo. The flatlanders (ABFO) have historically engaged, both in writing and declaration, that more research has been needed regarding their assumptions that human teeth are like fingerprints and bitemarks can be accurately measured and interpreted. As expected, the 2009 NAS Report made these two “commandments” the core of their blast-off on bitemarks and opined that they “might” be validated by proper research. The proper research has arrived.

Unknown (I am assuming) by the NAS when their committee met with Dr. David Senn in April 2007 as the single bitemark proponent to speak before this group, relevant research at the U of Buffalo had already been initiated. If Senn had been aware of it, I am sure he would have praised it to the NAS as examples of dentistry’s forward thinking commitment to scientific truth. He didn’t, however bring it up. He spoke eloquently regarding the challenges to bitemark identification. So well, in fact, the NAS adopted, in toto and verbatim, his text and republished it as their findings. The rub for the ABFO today is that the Buffalo research has addressed the issues identified in Dr. Senn’s testimony to the NAS committee and it is game over for the “skin readers” as a stand alone forensic tool. DNA from saliva from a bitemark is the optimum method for criminal justice.

What Senn has done since the 2009 Report is to claim in his (with co-editor Dr. Paul Stimson) 2010 text “Forensic Dentistry” that the NAS was misled by the Galileans whose opinions were cited alongside his in the Report. Such is the slippery slope of post-hoc backtracking away from the NAS by him and those bitemark practitioners criticized by the NAS. Since the NAS results showed it untenable to continue the status quo of the culture of bitemark identifications, the best three choices by Senn were to call the Congressional mandated review committee stupid, biased or ill prepared to render an opinion.

This theme of revisionism (rewriting history) and denial continued within the ABFO as evidenced by a lack of ABFO response to neither the NAS, nor the above stated anti bitemark research until this last February, at the ABFO annual meeting in Chicago. Some speakers presented public views that significant limits on bitemark opinions should be adopted and followed by its members. Kudos for that, but their rules and procedures manual still lack any restrictions in that regard AND the silence or vacuum of proofs on the science behind their courtroom declaration of probabilities of biter identification is deafening.

In Chicago there was a “members only” ABFO meeting with the Buffalo research team (with one invited non ABFO guest allowed at the last minute). Peter Neufeld of Cardozo Law’s Innocence Project and Michael Baden attempted to attend, but were turned away at the door. Its “aim”, according to the ABFO, was to have the Buffalo team present their compilation of 8 peer-reviewed papers on the match rates of human teeth (similarities of dentition within studied population groupings) and the uncontrollable physical variables of skin as an impression material. Their process of investigation was clearly organized and questions from the group were allowed. The only potential for dissension surfaced when there was a demand by Senn (the NAS bitemark presenter) for the team to publish a disclaimer that their findings had little to do with the issue of the actual practice of bitemark identification. The polite answer offered to him was to perform his own research to refute the implications of the Buffalo findings. This was truly an academic piece de resistance.

My final comment on the inanity of these bitemark true believers is the red herring strategy promulgated by a blogger whose glory board can be seen at Dr. Roger Metcalf’s blog. The publication of attack opinions on the veracity and research credentials of the Buffalo team resides on this site. The will to survive in the face of bitemarks’ non probative determination by the US Congress entices desperate people to reveal more about themselves than anyone wants to know.

Whilst a few will opine that bitemarks are valid given certain conditions, what will it take for them to outline and make clear those conditions? How many more exonerations will it take for the ABFO to realize that this fictitious, subjective “skin reading” and comparison to a suspect’s dentition is founded mainly upon the pompous attitude of some dentists claiming expertise based upon experience and supported by their so called scientific methodology? There are many dedicated scientists and dentists who have spent years working to become ABFO board certified. Those who have recognized the current research trends and the limitations of bitemark analysis need to take a stronger stance in reforming the ABFO rules and procedures in order regain credibility in the forensic science and legal communities. It is our obligation to the public we serve to see that these changes are made.

Summary: The “skin readers” in dentistry continue to harass and slander members of the broader and more sophisticated scientific community who are developing a research based foundation for the admissibility or inadmissibility of bitemark opinions in court. The research and actual case analyses over the last ten years have seriously undermined the use of bitemark patterns by prosecutors. The few die-hard dentists who continue to press for its use in criminal investigations are now resorting to personal attacks, misinformation and red herring objections to the peer reviewed articles pointing out the failure of bitemark comparison as a forensic discipline.

Bitemark Book Review

Forensic Odontology is a fascinating and challenging subject. The explosion of technological and procedural advances coupled with the general publics increased awareness through the media such as “CSI” has made forensic sciences appealing to many and seemingly infallible to others.

I have known Dr. Bowers for over twenty years. We first made acquaintance in Louisville, Kentucky in 1989 while challenging the ABFO dental certification board examination. Over these years he has earned the respect of all others in this field with his determined dedication to further forensic odontology into a respected discipline of the forensic sciences.

The second edition of “Forensic Dental Evidence: An Investigatorʼs Handbook” edited by Dr. C. Michael Bowers is written for those whose desire the knowledge, background and understanding of forensic dentistry. This book is essential reading and a valuable asset for any investigator, lawyer, medical examiner, nurse or dentist that has an interest or a role in a forensic dental case.

A highlight of this handbook is the discussion of the wrongful convictions and erroneous bitemark opinions that have surfaced in the past decade. In the early 1990s Dr. Bowers and others become cautious in the manner in which bitemark opinions were being used to identifying specific individuals in an open population. Currently there have been 10 exonerations of individuals who have served many years in prison that were falsely imprisoned as a result of faulty bitemark evidence and incorrect opinions. These opinions were not based in science and were without validity or reliability. Dr. Bowers asan impartial dental expert and DNA evidence resulted in the exoneration of these innocent individuals.

Dr. Bowers determined work in educating and informing the forensic community of the need for scientifically validated opinions in the 1990s went largely neglected by forensic dentists. In 1999 the ABFO performed a bitemark workshop to examine the ability of the expert to properly discern the biter from a lineup of unknowns. The ABFO published a paper with the results that reported the ability of the forensic dentists to identify the correct perpetrator with moderate accuracy of 86%. What was not reported was the high level of false positives that accompanied these findings. Dr. Bowers high ethical standards compelled him to uncover the actual findings that revealed this high false positive rate that was not exposed in the scientific paper published by the ABFO.

Recognizing that improvements were necessary in the forensic sciences Congress directed the National Academy of Science to study the problem. In 2009 the National Academy published a report called “Strengthening Forensic Science in the UnitedStates: A Path Forward” which was a comprehensive review of all the forensic sciences,including bitemark analysis. The findings from the report were the same as Dr. Bowers had been teaching and writing about for years. It was not until after the report was published did the dental forensic specialty group begin to acknowledge the need for change. Fortunately this process has begun and positive changes are currently being
made. This handbook relates and discusses all the problems identified by the National Academy of Science.

In this book Dr. Bowers has partnered himself with many of the worlds foremost forensic scientists and dental experts. This handbook offers the latest information available to the forensic community and beyond. It will function to advance the profession and allow justice to be served for all.