Published February 22, 2016
Peter and Mary Bush, forensic scientists in the School of Dental Medicine, had much to celebrate during the past week.
Their work — several studies that found the science behind bite-mark analysis unsound — helped lay the foundation for a landmark recommendation by the Texas Forensic Science Commission to ban the form of evidence from being used in the courtroom.
A recommendation that will “start a domino effect for much needed reform,” says Peter Bush, director of the UB South Campus Instrument Center.
The second domino may fall as soon as this week at the 68th Annual Scientific Meeting for the American Academy of Forensic Sciences (AAFS).
The meeting will draw forensic experts from across the nation and all eyes will be on forensic dentistry, says Peter Bush, who is attending the meeting being held Feb. 22-27 in Las Vegas.
Although the Texas commission sided against using bite-marks as evidence, the battle is far from over across the nation’s 49 other states.
The AAFS meeting will include several presentations from forensic dentistry experts that will argue for the continued use of bite-mark analysis.
The Forensic Science Accreditation Board, responsible for certifying members of the American Board of Forensic Odontology, also will meet to review its certification requirements, which call for forensic dentists to have testified on bite-marks in at least seven criminal cases.
And despite the decision in Texas, judges — who decide on a case-by-case basis what evidence they deem admissible — still retain the power to allow the now-controversial bite-mark evidence in court.
“Bite-mark evidence is going to be much more difficult to litigate,” says Peter Bush. “The courts are going to re-examine past cases, but the question is, going forward, whether the judges will heed the recommendation and refuse to admit bite-mark evidence in future cases.”
Bite-mark analysis, which compares the teeth of crime suspects to the bite-mark patterns on victims, is widely accepted in criminal courts and often is presented as key evidence in prosecutions.
The analysis relies on the theory that dental impressions are like fingerprints: unique to every individual and that human skin can accurately record that uniqueness.
A notion that Peter Bush and Mary Bush, associate professor of restorative dentistry, disproved in their research. Their results found that some dental arrangements can be similar enough to render them indistinguishable from another, and that a set of teeth could inflict varied bite patterns.
“With no scientific basis supporting this technique, the analysis can amount to no more than subjective guessing,” Mary Bush says. “As such, it should be no surprise to see that a number of tragic errors have resulted.”
At least 24 people convicted with bite-mark evidence were later exonerated after DNA testing, according to the Innocence Project, an organization committed to exonerating wrongly convicted people.
The fates of hundreds of men and women, including many on death row, still hang in the balance.