A recent series in the Washington Post analyzed some of the questions surrounding the subjective field of bite mark analysis in criminal court proceedings. The articles addressed the field itself, particularly the American Board of Forensic Odontology (ABFO) and its advocates.
This isn’t the first time that the validity of bite mark analysis has been called into question. The National Academy of Sciences published a report challenging its validity in 2009, and a number of court cases have questioned it as well. There have been a number of wrongful convictions overturned in recent years due to bite mark evidence that was later disproven.
Perhaps the most troubling example of the subjectivity of the field of bite mark analysis was a test of a new process of evaluation given to a group of 39 odontologists. They were asked to assess photographs three separate cases. First, they had to answer the following three questions:
- Is there sufficient evidence in the presented materials to render an opinion on whether the patterned injury is a human bite mark?
- Is it a human bite mark, not a human bite mark, or suggestive of a human bite mark?
- Does the bite mark have distinct, identifiable arches and individual tooth marks?
The group of professional forensic odontologists only reached the same conclusions on all three questions on 8 of the 100 cases that they assessed using these parameters, which don’t even include matching a set of teeth to a person’s arm. Consensus is a very important aspect of scientific methodology, one that bite mark analysts have struggled to establish. Even more questionably, the AFBO has said it was going to change the parameters of the study and do it again.
Both defense and prosecution can use expert witnesses to augment their case, but not all experts are created equally. A well-informed defense attorney can make sure that questionable evidence like some bite mark analysis testimony isn’t used to hurt your case.
WashingtonPost.com, “How credible is bite mark evidence?” Radley Balko, 8 April 2015