This item is excerpted from a NYTimes Opinion article by Dr. Greg Hampikian, a professor of biology at Boise State University. Read the whole article here: www.nytimes.com.
Before you give the police a DNA sample, read an alarming new study of crime laboratories published this summer [2018], the largest study of its kind. Researchers from the National Institute of Standards and Technology gave the same DNA mixture to about 105 American crime laboratories and three Canadian labs and asked them to compare it with DNA from three suspects from a mock bank robbery. In [the] study, 74 out of 108 crime laboratories implicated an innocent person in [the] hypothetical bank robbery. The test results are troubling, especially since errors also occur in actual casework.
As DNA testing has become more sensitive, most laboratories are now able to produce profiles from anyone who may have lightly touched an object. The result is that DNA mixtures have become more common, making up about 15 percent of all evidence samples.
There are methods to reanalyze old DNA mixture data using computer programs that can help analysts correct errors, without any new lab testing. Many crime labs now have access to these programs and use them on current cases. But they could and should easily go back and re-examine old DNA mixtures to correct tragic mistakes.