They never said we wouldn't get our hair mussed

A review of death penalty convictions by the federal government has turned up 27 instances in which “exaggerated scientific testimony” from FBI forensics experts may have played a role. It’s unclear how many times such testimony led to false convictions or could nullify correct convictions the Washington Post reports. However the assessment did lead to a last minute stay of execution in May.

The testimony is the “once-widespread practice” where experts said that hair found at crime scenes could be used to identify suspects:

Since at least the 1970s, written FBI Laboratory reports typically stated that a hair association could not be used as positive identification. However, on the witness stand, several agents for years went beyond the science and testified that their hair analysis was a near-certain match.