We have previously written about the public misperceptions of forensic testing. Shows like CSI have convinced Americans that forensic tests performed in criminal cases are completely reliable and produce results that are indisputable.
DNA testing is the most reliable and accurate forensic tool, and it still doesn't rise to the standard mentioned above. But some of the other forensic tests now in use are pseudo-scientific and dangerously inaccurate. Perhaps the best current example is bite-mark analysis.
Prosecutors have long tried to use testimony from so-called experts in "forensic dentistry" to link defendants to violent crimes in which the victims were bitten. The idea is to match the bite marks on a given victim to the set of teeth that caused them. While this practice has always been somewhat controversial, more recent studies have shown that it is also entirely unreliable.
Human skin is malleable, and wound patterns caused by teeth can change shape over time. And matching bites is more difficult than it sounds. One study revealed that among a group of forensic dentists studying pictures of bite marks, there was significant disagreement on whether certain bite wounds were even caused by humans.
Thankfully, bite-mark analysis has been falling out of favor in recent years. And it may become even less used now after a recent announcement from a scientific commission. The Texas Forensic Science Commission recently announced that, based on the research it has conducted, bite-mark analysis should not be admitted into evidence in criminal trials. The group said that it "does not meet the standards of forensic science."
It is somewhat ironic for an announcement like this to come from Texas. The state has among the highest rates of wrongful conviction in the nation, and it also relies heavily on the death penalty as a form of punishment. Nonetheless, the commission's findings will likely be influential across the country, including here in Wisconsin.