The exoneration last week of a New York State man in a case based on bite-mark evidence was not an aberration, says the New York Times. Prosecutors have invoked bite-mark matches to secure convictions many times, only to see these convictions overturned when DNA or other evidence has become available. Bite-mark analysis remains an inexact tool. A 1999 study by a member of the American Board of Forensic Odontology found a 63 percent rate of false identifications. Experts note a mix of ignorance on the part of jurors and defense lawyers about the evidence's scientific shortcomings and the overzealousness of prosecutors and their expert witnesses, who may be too quick to validate an unproved technique.
Courts are growing more skeptical of the absolute conclusions drawn by bite-mark experts and are becoming more receptive when defense lawyers rebut the analysis. Lawyers are taking steps to counter what they call the “C.S.I. effect,” when juries become overly impressed by forensic evidence. During jury selection, it is not uncommon for them to ask potential jurors about their television-watching preferences to weed out those who seem unable to separate fact from fiction. The key, experts say, is for lawyers to know enough about the subjective components of bite-mark analysis to refute it effectively in court.