In 1987, Texas inmate Steven Mark Chaney was sentenced to life after a dental expert testified that his teeth had caused marks on the arm of a murder victim. This same expert has now repudiated his testimony as unfounded, reports The New York Times.More than a dozen Americans have now been exonerated in cases involving debunked bite-mark testimony. And Texas is leading the way in this little-recognized corner of forensics.
The Texas Forensic Science Commission is now asking whether bite-mark comparisons should have any role in the courtroom. Forensic science more broadly is in turmoil. Many long-used methods, like handwriting analysis and microscopic hair comparisons, simply do not hold up under scrutiny. Even fingerprints and certain kinds of DNA matches are not quite as certain as many once believed.