Nearly every criminal case reviewed by the FBI and the Justice Department as part of a massive investigation started in 2012 of problems at the FBI lab has included flawed forensic testimony from the agency, government officials said.
The findings troubled the bureau, and it stopped the review of convictions in August. Case reviews resumed this month at the order of the Justice Department, the officials said.
U.S. officials began the inquiry after The Washington Post reported two years ago that flawed forensic evidence involving microscopic hair matches might have led to the convictions of hundreds of potentially innocent people. Most of those defendants never were told of the problems in their cases.
The inquiry includes 2,600 convictions and 45 death-row cases from the 1980s and 1990s in which the FBI’s hair and fiber unit reported a match to a crime scene sample before DNA testing of hair became common. The FBI had reviewed about 160 cases before it stopped, officials said.
The investigation resumed after the Justice Department’s inspector general excoriated the department and the FBI for unacceptable delays and inadequate investigation in a separate inquiry from the mid-1990s. The inspector general found in that probe that three defendants were executed and a fourth died on death row in the five years it took officials to reexamine 60 death-row convictions that were potentially tainted by agent misconduct, mostly involving the same FBI hair and fiber analysis unit now under scrutiny.