As TalkLeft discussed here, Roy Brown was convicted of a brutal murder on the basis of dubious bite mark evidence. Fifteen years later, a DNA analysis proved that the state's bite mark expert was wrong.

A piece in today's NY Times takes a helpful look at bike mark evidence.

What happened to Mr. Brown is hardly an aberration. Prosecutors have invoked bite-mark matches to secure convictions in numerous cases, only to see these convictions overturned when DNA or other evidence has become available.

In spite of the evolution of other forensic sciences, bite-mark analysis remains an inexact tool. A 1999 study by a member of the American Board of Forensic Odontology, a professional trade organization, found a 63 percent rate of false identifications.

Why do prosecutors consistently rely upon such consistently unreliable evidence?

There is, experts say, 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 are seen as too quick to validate an unproven technique.