Bite mark analysis may result in false convictions

Widely accepted in criminal courts and often presented as key evidence in prosecutions, bite mark analysis is actually "far from an exact science" and can lead to false convictions, says a new study.

Bite mark analysis compares the teeth of crime suspects to bite mark patterns on victims. But a single bite mark is not distinct enough to be linked to a specific individual, said one of the researchers H David Sheets from Canisius College in New York, US.

It can actually point to many different individuals," Sheets noted.

This means that a false identification is possible, which can lead a police investigation away from the real perpetrator and toward an innocent individual.

"People assume that it is close to fingerprints in terms of accuracy," Sheets pointed out.

"But the notions that a person's dentition is unique or that the human skin can accurately record an individual's bite mark have never been validated scientifically," Sheets added.

Using a variety of dental impressions, scientists examined more than 1,000 human dentitions and studied hundreds of bite marks in cadaver skin.

With the help of computer analysis and applied statistics, the team then worked to match its database of bite marks to the correct dental impressions.

"When the dental alignments were similar, it was difficult to distinguish exactly which set of teeth made which bites," Sheets stated.

"This is an example of where science can help prevent future wrongful convictions and perhaps even provide some social justice to those already convicted," Sheets said in an official statement.