DNA Testing and Errors

A recent NYT op-ed strongly alerted readers to a study that found errors in DNA testing. The National Institute of Standards and Technology gave the same sample of DNA mixtures to 105 US crime labs and 3 Canadian ones and asked them to compare it to the DNA of 3 suspects from a mock robbery. A DNA mixture is a biological sample of 2 or more individuals from which a DNA profile could be drawn. Today’s DNA testing is advanced enough that an analysis can be done even if someone has lightly touched an object. The labs correctly identified 2 of the suspects, but 74 got the third one, an innocent person, wrong. The implications for this are according to the piece’s author, Greg Hampikian, a professor of biology at Boise State University, alarming. Think of how often DNA testing is used and relied upon. Certainly it has freed the innocents, but that was when it was supervised by organizations like the Innocence Project. But DNA has also convicted many innocents. The use of DNA mixtures have become more common, and according to the author now make up 15% of DNA testing. This is apparently not the only study revealing errors with DNA testing, Hampikian also mentions the problems found in a similar study.  What is particularly troubling to me is that when one further factors in the fact that minorities are more likely to be arrested and end up in jail, it would seem that people of color would be far more affected by DNA testing errors. The good news we are told is that computer programs exist to reanalyze old mixture and correct errors. But of course that means someone must first suspect an error, or what is far more relevant, an accused or convicted person must have a strong advocate.