In a Jan-Febn 2006 article "Tarnish on the Gold Standard" in The Champion Professor William C. Thompson wrote, "The surprise for defense lawyers who have managed to gain access to these [corrective action] files is how voluminous they are. Errors occur regularly. Files from Orchid- Cellmark’s Germantown, Maryland facility, for example, show dozens of instances in which samples were contam- inated with foreign DNA or DNA was somehow transferred from one sample to another during testing. I recently reviewed the corrective action file for an accredited California laboratory operat- ed by the District Attorney’s Office of Kern County (Bakersfield). Although this is a relatively small laboratory that processes a low volume of samples (probably fewer than 1,000 per year), during an 18-month period, it documented multiple instances in which (blank) control samples were positive for DNA, an instance in which a mother’s reference sample was contaminated with DNA from her child, several instances in which samples were accidentally switched or mislabeled, an instance in which an analyst’s DNA contaminated samples, an instance in which DNA extracted from two different samples was accidentally combined into the same tube, falsely creating a mixed sample, and an instance in which a suspect tested twice did not match himself (probably due to another sample-labeling error)."
Professor Thompson went on to write, "Given the unexpectedly high frequency of contamination in DNA test- ing we have just discussed, it is interest- ing, and not at all surprising, that the major form of fakery discovered to date involves control samples known as extraction blanks that are designed to detect contamination." I am posting this because it may be that the analyst in question falsified negative controls (at least that is my suspicion based on the news stories). I would be surprised if that is all that she did wrong.
