Over 20 people have been exonerated of crimes that they were convicted of, or arrested for, as a result of bitemark evidence. The data refuting this discipline is becoming more and more difficult to ignore, but courts in Texas are still resistant to accept this new information.
It’s becoming more obvious that it doesn’t work
Studies published by the NIST (National Institute of Standards and Technology), the NAS (National Academy of Sciences) and other groups have found that bitemark evidence has little foundation in science and tends to be extremely unreliable. This has been shown multiple times through studies like these, and the answer has only begun to grow more resoundingly clear each time.
Gathering bitemark evidence is the discipline in which an expert is supposed to be able to identify apparent marks on a person’s skin made from being bitten. You have to take a few things for granted in order to believe that the science of bite mark evidence is legitimate. One is that it is even possible for a human to identify and analyze the traces left behind on human skin from alleged bites just by looking at them.
Another assumption with bitemark evidence is whether or not human skin is able to retain the impression and marks enough for them to be interpreted and positively identified afterward. And finally, you have to believe that every person’s teeth are in a unique alignment for bitemark evidence to work.
Courts still won’t listen
The consensus is that further analysis is still needed. But the data seems to keep pointing to the fact that the assumptions accepted in the practice of bitemark evidence aren’t as reliable as the experts in this field would like to believe.
Unfortunately, it’s not clear if or when this information will work its way into the legal justice system. If they were to accept this news, courts have to re-open and investigate hundreds of criminal defense cases, so the truth about bitemark evidence will likely continue to fall on deaf ears.
The NAS published a report in 2009 on bitemark evidence’s lack of scientific backing. A new report made by the National Institute of Standards and Technology further supported this conclusion.