Delaware Attorney General Kathy Jennings on Monday said that a nonprofit group was conducting an independent review of decades-old criminal convictions in cases involving “potentially questionable” hair evidence.

Jennings said the Delaware Department of Justice had enlisted Prosecutors' Center for Excellence to conduct the review, after the Federal Bureau of Investigations announced in 2015 that its own internal probe had revealed widespread error in FBI testimony regarding hair analysis that the bureau had conducted in criminal cases prior to the year 2000.

According to Jennings' announcement, at least 90 percent of trial transcripts covered in the FBI review contained erroneous statements or lab reports from FBI examiners.

“We have a responsibility to make the best decisions we can based on the facts as we understand them,” Jennings in a statement. “Given the serious issues that the FBI's errors have raised, I believe that this review is the most responsible step we can take. I'm grateful for the impartiality and experience of the experts we've enlisted and will address the impact of their findings on the integrity of the convictions.”

Jennings said the PCE, which provides expert advice, research and consulting to prosecutors in the United States and Canada, has been evaluating Delaware cases since early February. Similar audits are already underway in other states, including Texas, Massachusetts and North Carolina.

According to the announcement, the FBI has notified the Delaware DOJ on a “rolling basis” of potentially tainted cases, since 2015. But prior to February, state prosecutors had been trying to assess on a case-by-case basis whether the role hair analyses played warranted further action.

Jennings said the “number of cases and the benefit of an independent assessment” had led the DOJ to seek the PCE's help.

“Attorney General Jennings is making the right decision by opting for a proactive, independent review of convictions that could be affected by the FBI's admission of error in its hair analysis,” said Kristine Hamann, executive director of the PCE. “We owe it to the justice system to get this right and are looking forward to completing a thorough review.”

Defendants in individual cases were notified at the same time as prosecutors, and some are currently pursuing post-conviction relief in Delaware courts. In one case, Jennings said, the DOJ has supported retesting hair evidence with current technology.

However, any finding of flawed evidence would not automatically result in convictions being overturned, if there is other evidence—like confessions or DNA analysis—to support the convictions, the DOJ said.