The FBI admits that, hey, thanks to the possible overreliance on the meaning of hair analysis, it may have been wrong in 2,000 or so cases--some involving the death penalty.

As reported last week by Michael Doyle at McClatchy:

The FBI will review thousands of old cases, including some involving the death penalty, in which hair samples helped secure convictions, under an ambitious plan made public Thursday.

Chapendra / Foter / CC BY-NCChapendra / Foter / CC BY-NC

More than 2,000 cases the FBI processed from 1985 to 2000 will be re-examined, including some in which execution dates have been set and others in which the defendants already have died in prison. In a key concession, Justice Department officials will waive usual deadlines and procedural hurdles that often block inmates from challenging their convictions....

The study will focus on whether analysts exaggerated the significance of their hair analyses or reported them inaccurately. Defendants will be notified and free DNA testing offered if errors in lab work or testimony are detected.

“The government’s willingness to admit error and accept its duty to correct those errors in an extraordinarily large number of cases is truly unprecedented,” declared Peter Neufeld, a co-director of the Innocence Project....

[FBI Special Agent Ann] Todd called microscopic hair analysis “a valid forensic technique and one that is still conducted at the lab” in conjunction with DNA testing. But in some cases, defense attorneys say, lab analysts have overstated the significance of their findings.

And we already have reason to believe it can be a big problem:

In 1981, for instance, an 18-year-old Washington resident named Kirk Odom was convicted of rape and sodomy. At his trial, an FBI analyst testified that Odom’s hair samples and samples taken from the crime scene “were indistinguishable” and that this was very rare. Odom was convicted and served about 22 years in prison. In 2011, he was exonerated by DNA testing that wasn’t available at the time of his original trial...

Of 310 individuals exonerated through DNA evidence, according to an Innocence Project database, 72 were convicted in part because of microscopic hair evidence.

Some died before they could be exonerated...

A spokesman for the Innocence Project is:

hopeful that state crime labs will also recognize their duty” to confirm the accuracy of past lab tests, although the agreement announced Thursday covers only testimony and reports from FBI lab analysts.

Radley Balko reported extensively for Reason on some very egregious cases of bad science in the service of winning prosecutions, out of Mississippi. All Americans should read his new book Rise of the Warrior Cop.