Bite mark analysis is a portion of forensic odontology. It is a way to match marks on a victim’s body with a potential perpetrator’s teeth patterns, based on the theory that the victim was bitten by the suspect. Across the country in many different cases, bite mark evidence has been used at trial. Often, the bite mark evidence is the most powerful forensic evidence going against a defendant.
The problem is, bite mark analysis has no real science or research supporting it. There are a number of reasons why testimony regarding bite mark analysis can be incredibly flawed. One reason is that when comparing a suspect’s teeth to a bite mark on a victim, it is not nearly the same as comparing to an impression made at a dentist’s office. Typically the suspects teeth are being compared to a bite into soft tissue or skin. Human skin can heal, it can swell, the body may have even decayed between the time of the crime and when the body was discovered. All of these things can warp the clarity of the bite mark and damage the accuracy of trying to match up a dental impression with the bite. In addition, the teeth of the suspect are typically being compared to a photo of the bite rather than the actual bite, which further skews the reliability.
Another reason why bite mark evidence can be very misleading is that it is presented in court as being right alongside DNA evidence. This is simply not true, DNA is definitively unique to every individual person but bite patterns are simply not this scientifically unique. In fact, it is not even close. Different analysts have come to vastly different conclusions while evaluating the same bite mark evidence. It is dangerous to present such a subjective opinion as scientific physical evidence in court because that kind of evidence is highly persuasive to a jury.
Some experts say that bite mark evidence should only be used to eliminate a potential suspect based on the bite mark not being able to have come from them. At best, bite mark testimony should only conclude that the suspect cannot be excluded from the possibility of inflicting that bite. But, according to forensic dentists, if a bite mark is the only physical evidence against the suspect and the claim is that they are the only person who could have made that bite, that is junk not science.
Bite mark testimony has been responsible for numerous wrongful convictions. One notable case is that of Kennedy Brewer. Brewer was convicted of raping and killing a three-year old girl who was found in lake with several marks on her body that forensic odontologists deemed to be bite marks. It is unclear whether these marks could have come from animals or bugs living in the lake or whether the marks had any scientific integrity after the body had decayed in a body of water. Nevertheless, bite mark testimony convicted Kennedy Brewer of capital murder and sent him to death row. When Brewer was exonerated through post-conviction DNA tests, another innocent man was also able to be exonerated. Levon Brooks was serving his sentence for a very similar rape and murder. When the real perpetrator was found through DNA in Kennedy Brewer’s case, he was found to be responsible for the additional rape and murder that Brooks was convicted of.
Another notable case of wrongful conviction due to the influence of bite mark testimony is that of Ray Krone. After testimony in court from a bite mark expert saying that Krone’s teeth matched a bite mark on the victim, Krone was convicted of murder and sentenced to death. This bite mark analysis was the only physical evidence linking him to the crime. Ray Krone was released in 2002, after 10 years in prison, following DNA evidence proving his innocence. These men were fortunate enough to have their innocence proven. But, there are still countless others sitting in jail convicted of crimes because of the power of bite mark evidence testimony.