(Image: Courtesy of the FBI)

FBI examiners had presented scientifically-flawed hair analysis at criminal cases nationwide for multiple decades, occasionally resulting in innocent people being convicted for crimes they did not commit, the Bureau admitted in 2015.

Nearly two years later, criminal cases in a dozen states over several decades featuring the hair assessments are now being combed through, the National Association of Criminal Defense Lawyers told Forensic Magazine.

Groups in Iowa, North Carolina, Massachusetts, Texas, California, New York, Washington, Virginia, Washington D.C. are currently reviewing criminal cases involving the hair-analysis techniques, said Vanessa Antoun, senior resource counsel with the NACDL, which is keeping track of the efforts, which are done on a jurisdiction-by-jurisdiction level.

Coupled with other states monitored by the Midwest Innocence Project, the number of states is roughly a dozen, she added.

But not all those efforts have yet been made public, she told Forensic Magazine in a recent interview.

The vast majority of the cases in which FBI hair examiners testified were at the state as opposed to federal level, according to Antoun.

But some states did have their own examiners trained at a two-week hair and fiber school run by the Bureau, she added. One of those states was Florida, which had its own experts testifying in cases statewide. (Some 48 states had sent experts to the FBI training in the years it was held).

Approximately 3,000 cases involved the flawed FBI hair analysis from 1985 to 1999. The FBI is still reviewing those cases for errors by examiners, who were using subjective measures in testimony and determinations about matches from suspects to crime scenes. That announcement was made by the Bureau in April 2015. But from the outset, the Innocence Project and other defense advocates said the pool of potentially-related criminal cases could be much larger than the initial 3,000. The Bureau said it had difficulties identifying cases prior to 1985, when it started its computer system – and the federal agency initially started its hair analysis program in the 1930s.

FBI Director James Comey sent a letter to U.S. governors in June 2016 in which he assured the states that after 1999, the FBI had added mitochondrial analysis to further validate the testimony of experts.

Comey asked the governors to ask state and local crime labs to review their own cases to validate the hair evidence presented at courts before 2000.

“We want to make sure there aren’t other innocent people in jail based on our work,” Comey wrote. “Unfortunately, in a large number of cases, our examiners made statements that went too far in explaining the significance of a hair comparison and could have misled a jury or judge.”

Nine prisoners were executed in the United States based on cases based at least partly on hair evidence. Another five died while behind bars. However, the Innocence Project, the NACDL and the FBI are not identifying those prisoners, and are instead relying on surviving relatives to decide whether to speak to media.

Douglas W. Deedrick, the chief of the FBI’s Trace Evidence Unit, wrote in July 2000 that hair evidence needed to be carefully handled by prosecutors in criminal cases. That admission came months after the FBI apparently changed its flawed methods.

“Although hair evidence is a valuable tool in human identification,” Deedrick wrote, “it is difficult to establish a statistical probability for a particular association due in part to the lack of reliable quantitative assessments of the microscopic characteristics present in hairs.”

A series of exonerations, retrials, and multimillion-dollar lawsuits have resulted in DNA testing of cases featuring the hair evidence. One of the foremost cases was that of Timothy Bridges, who served 25 years in prison based on two hairs found at a rape scene; he was released in 2015, given a full pardon by the North Carolina governor last month, and has a major lawsuit pending.