Junk Science And the Courts

The decision whether to allow a new field of forensics into court is made by a judge, not a scientist, or even a fellow practitioner. Judges typically look for guidance on these questions not from scientists, but from other judges. The briefs in such challenges are by lawyers. Judges tend to err on the side of letting evidence in, on the assumption that our adversarial system will sort it out. Even once we discover that a field is scientifically suspect, it's difficult to get the courts to even acknowledge it, much less stop it from being used again, much less correct the cases that may have already been tainted. [The forensic science fields of handwriting, bite mark, hair and fiber, and firearms identification have produced, over the years, a lot of junk science that helped send many innocent defendants to prison.]

Radley Balko, Reason Magazine, June 2018