The Justice Department and the FBI have formally acknowledged that almost all of the examiners working in the FBI Laboratory's microscopic hair comparison unit gave fundamentally flawed testimony in almost every trial they testified in, during a more than two-decade-long period before 2000, according to a report from the Washington Post.

Twenty-six out of the 28 examiners working in the lab reportedly overstated forensic matches in a manner that favored prosecutors in over 95 percent of 268 trials that have been review by the National Association of Criminal Defense Lawyers and the Innocence Project.

The cases being reviewed by the organizations, in cooperation with the government, include 32 defendants who have been sentenced to death. Fourteen of those defendants have either been executed or have already died in custody, the Post reported.

Experts who spoke to the Post branded the FBI's use of microscopic hair comparisons “a complete disaster”. The FBI used the analysis of hairs in a similar fashion to fingerprint or DNA evidence in court cases, despite the fact that there is no body of accepted research on how often hair from different people may appear to be the same when subjected to microscopic analysis.

In a statement to the Post, the FBI said that they "are committed to ensuring that affected defendants are notified of past errors and that justice is done in every instance. The department and the FBI are also committed to ensuring the accuracy of future hair analysis, as well as the application of all disciplines of forensic science."

Legal analysts told the Post that the admissions from the FBI and Justice Department were highly significant, and illustrated a systemic failure in the criminal justice system to keep bogus scientific testimony from juries.