In a Landmark Decision, Texas Forensic Science Commission Issues Moratorium on the Use of Bite Mark Evidence

“For far too long courts have permitted this incredibly persuasive evidence that is cloaked in science, when in fact there has been no scientific research to substantiate the practitioners’ claims that it is possible to identify someone from a bite mark,” said M. Chris Fabricant, Director of Strategic Litigation for the Innocence Project.  “By recommending a moratorium on further use of this unscientific evidence in Texas prosecutions, the Texas Forensic Science Commission has taken a giant step in purging unscientific and unreliable bite mark evidence from court rooms nationwide.”

Before reaching its decision, the Commission conducted six-month investigation and a held day-long  hearing in November where it heard from experts on all sides of the debate.  During the hearing, it was revealed that Dr. Adam Freeman, the president-elect of the American Board of Forensic Odontologist (ABFO), and Dr. Iain Pretty conducted a study of board certified forensic dentists where they asked to analyze photographs of 100 injuries, and in most cases, the practitioners were unable agree on which injuries were even bite marks.

Despite the fact that for decades courts have permitted forensic dentists to testify in criminal trials, there is a complete lack of scientific support for claims that a suspect can be identified from an injury on a victim’s skin.  This was noted in the National Academy of Science’s groundbreaking 2009 report,

Strengthening Forensic Science in the United States: A Path Forward

, which found, “no evidence of an existing scientific basis for identifying an individual [through bite mark comparison] to the exclusion of all others.”  Unlike the National Academy of Sciences’s report, however, the Commission specifically found that bite mark evidence should not be admitted as evidence.

In addition to recommending a moratorium barring prosecutors from using bite mark analysis in future prosecutions, the Commission ordered a review of past cases where the forensic practice was used.   The Commission will appoint a panel of experts, including forensic dentists, to review transcripts of the cases.  The American Board of Forensic Odontology pledged to help identify these convictions and stated that there are nine ABFO members practicing in Texas who will assist in this process.

The Innocence Project urged the Commission to investigate the use of bite mark analysis on behalf of Steven Mark Chaney.  After a thorough investigation by the Dallas District Attorney’s Conviction Integrity Unity, Chaney was released in October after wrongly serving 28 years for the murder of John Sweek based on the discredited testimony of two forensic dentists.  The case is now before the Texas Court of Criminal Appeals, which must review the uncontested findings of the lower court reversing Chaney’s conviction.  In addition to the Innocence Project, Chaney is represented by Julie Lesser, exoneration attorney of the Dallas Public Defender’s Office and the Southern Methodist University Innocence Clinic.