While DNA testing has proved to be precise in identifications, other types of forensic evidence have been determined to be unreliable. Many post-conviction matters that ultimately led to exonerations in Michigan and elsewhere included evidence that was based on bite mark comparisons. Yet, in a significant number of cases, prosecutors continue to present bite mark comparisons as crucial evidence.
Some believe that the elasticity of the skin, unlike a dentist’s mold, prevents bite mark comparisons to be as exact as DNA evidence. Other problems include the fact that different bite marks can be left on a victim’s skin by the same teeth. Also, when only partial bite marks are present, a different person’s teeth could have produced them.
The unreliability of this type of evidence is further underscored by the fact that even some of the most experienced forensic scientists have identified marks left by other injuries as caused by bite marks. Furthermore, marks left by teeth are not set in a mold that preserves them. Swelling, bruising and even healing can distort the original impressions within a short time. In a significant percentage of cases, evidence of bite marks is based on photographs, and there is no telling how many other people’s teeth might have left the same or similar marks.
Anyone in Michigan who was convicted after the prosecution’s key evidence was based on forensic science such as bite marks might have questions about the possibility of proving a wrongful conviction. The sensible step would be to retain the services of a criminal defense attorney. A lawyer with experience in dealing with post-conviction matters would be the most appropriate person to deal with the ensuing legal proceedings in pursuit of exoneration.