If you’ve ever watched “CSI” or any similar drama, you likely know that forensic evidence analysis is a sophisticated science that produces iron-clad results. Unfortunately, that conclusion is completely wrong. Many forensic tests that have been used for years are not very reliable, and some are so bad that they can’t honestly be called scientific.
To make matters worse, these tests often prove highly convincing to jurors because forensic “experts” are allowed to overstate the efficacy of their tests and the accuracy of results. This was the subject of an article in the New York Times about the increasing number of exonerations in recent years. In many of these cases, bad forensic science played a role in the original convictions.
The times studied a report from the National Registry of Exonerations and profiled three problematic tests (or overstated test results). The first two, microscopic hair comparison and bite-mark analysis are increasingly being debunked as pseudo-science.
Hair comparison simply involves looking at hair samples under a microscope to see if they match. There is do DNA analysis involved. The FBI relied on this test for decades, but in recent years, analysts for the Bureau have admitted that the conclusions one could draw from these tests were vastly overstated.
Bite-mark analysis involves looking at bite marks left on a victim and trying to match them to the teeth patterns of a suspect. Here’s the problem, though: Skin is incredibly malleable – especially when it has suffered injury. Visual matches are speculative, at best. In some cases, it is not possible to tell whether the bite was from a human or an animal, or even whether the injury was a bite to begin with.
The third problem profiled by the Times is known as DNA amplification. While DNA testing is perhaps the most accurate and useful forensic tool, there needs to be a sufficiently large sample to test. Some crime labs have started taking samples which are too small to test and using software to extrapolate results. Perhaps this technique could prove useful in the future, but it is not there yet. Some convictions have been overturned because the science simply doesn’t back it up.
Forensic evidence continues to play a major role in criminal cases across the country – including tests that are being challenged and debunked. If you are facing criminal charges and forensic evidence is a factor, you should seek the help of a criminal defense attorney who is ready to challenge the evidence and defend your rights at every turn.
