A law prof tries a simple way to explain what PCAST is concerned about. He also includes the following: [Brandon Garrett at Va. Law’s Faculty Q&A]

Few studies had been done examining how jurors appreciate some of the most commonly used forensics, including fingerprint evidence. [UVA Law professor] Greg Mitchell and I embarked several years ago on a series of studies, and what we discovered surprised me: I expected that we would find that when analysts gave conclusions exaggerating their certainty that prints came from a defendant, that jurors would place more weight on the evidence. Jurors were not overly affected by those over-statements. Instead it seemed as if just hearing the word “fingerprint” was enough to convince jurors that the defendant did it. In more hopeful news, though, we discovered in a second experiment that jurors were affected by hearing that there is a possibility of an error in fingerprinting. Still more promising, in a detailed follow-up experiment, we are exploring how jurors can be highly sensitive to information about the error rates, or the proficiency, of the particular fingerprint examiner. We plan to do more to explore these findings and make practical recommendations for testimony, reports and regulation of forensics in the courtroom.