Cleveland Wright has asked a D.C. Court judge to clear his name after new DNA test results in 2012 exonerated his co-defendant in two similar 1978 murders. (Alexandra Garcia/The Washington Post)

Cleveland Wright has asked a D.C. Court judge to clear his name after new DNA test results in 2012 exonerated his co-defendant in two similar 1978 murders. (Alexandra Garcia/The Washington Post)

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 last 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.

(Related: ‘Irreversible harm’ when FBI didn’t reveal flawed lab work in death-row cases)

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.

“I don’t know whether history is repeating itself, but clearly the [latest] report doesn’t give anyone a sense of confidence that the work of the examiners whose conduct was first publicly questioned in 1997 was reviewed as diligently and promptly as it needed to be,” said Michael R. Bromwich, who was inspector general from 1994 to 1999 and is now a partner at the Goodwin Procter law firm.

Bromwich would not discuss any aspect of the current review because he is a pro bono adviser to the Innocence Project, which along with the National Association of Criminal Defense Lawyers is assisting the government effort under an agreement not to talk about the review. Still, he added, “Now we are left 18 years [later] with a very unhappy, unsatisfying and disquieting situation, which is far harder to remedy than if the problems had been addressed promptly.”

Deputy Attorney General James M. Cole this month ordered that reviews resume under the original terms, officials said.

(Related: U.S. reviewing 27 death penalty convictions for FBI forensic testimony errors)

According to the FBI, the delay resulted, in part, “from a vigorous debate that occurred within the FBI and DOJ about the appropriate scientific standards we should apply when reviewing FBI lab examiner testimony — many years after the fact.”

“Working closely with DOJ, we have resolved those issues and are moving forward with the transcript review for the remaining cases,” the FBI said.

1 of 25 Full Screen Autoplay Close Skip Ad × Investigating flaws in forensics View Photos A Washington Post investigation reveals that Justice Department officials have known for years that flaws in forensic techniques and weak laboratory standards may have led to the convictions of innocent people across the country, raising the question: How many more are out there? Read related story. Caption A Washington Post investigation reveals that Justice Department officials have known for years that flaws in forensic techniques and weak laboratory standards may have led to the convictions of innocent people across the country, raising the question: How many more are out there? Read related story. Santae A. Tribble, photographed in public defender Sandra Levick’s office in Washington last month. Tribble spent 28 years in prison based largely on analysis of hairs found at the scene of a taxi driver’s murder in 1978. More advanced DNA testing showed that none of the hairs used as evidence shared Tribble’s genetic profile. A judge has vacated his conviction and dismissed the underlying charges. Alexandra Garcia/The Washington Post Buy Photo Wait 1 second to continue.

Emily Pierce, a Justice Department spokeswoman, said: “The Department of Justice never signed off on the FBI’s decision to change the way they reviewed the hair analysis. We are pleased that the review has resumed and that notification letters will be going out in the next few weeks.”

During the review’s 11-month hiatus, Florida’s Supreme Court denied an appeal by a death-row inmate who challenged his 1988 conviction based on an FBI hair match. James Aren Duckett’s results were caught up in the delay, and his legal options are now more limited.

Revelations that the government’s largest post-conviction review of forensic evidence has found widespread problems counter earlier FBI claims that a single rogue examiner was at fault. Instead, they feed a growing debate over how the U.S. justice system addresses systematic weaknesses in past forensic testimony and methods.

“I see this as a tip-of-the-iceberg problem,” said Erin Murphy, a New York University law professor and expert on modern scientific evidence.

“It’s not as though this is one bad apple or even that this is one bad-apple discipline,” she said. “There is a long list of disciplines that have exhibited problems, where if you opened up cases you’d see the same kinds of overstated claims and unfounded statements.”

Worries about the limitations and presentation of scientific evidence are “coming out of the dark shadows of the legal system,” said David H. Kaye, a law professor at Penn State who helped lead a Justice Department-funded study of fingerprint analysis and testimony in 2012. “The question is: What can you do about it?”

Courts and law enforcement authorities have been reluctant to allow defendants to retroactively challenge old evidence using newer, more accurate scientific methods.

The Justice Department and FBI inquiry, which examines convictions before 2000, could provide a way for defendants to make that challenge. Because the government is dropping procedural objections to appeals and offering new DNA testing in flawed cases if sought by a judge or prosecutor, results could provide a measure of the frequency of wrongful convictions.

Responding to the FBI review, the accreditation arm of the American Society of Crime Lab Directors last year recommended that labs determine whether they needed to conduct similar reviews, and New York, North Carolina and Texas are doing so.

According to a Justice Department spokesman, officials last August completed reviews and notified a first wave of defendants in 23 cases, including 14 death-penalty cases, that FBI examiners “exceeded the limits of science” when they linked hair to crime-scene evidence.

However, concerned that errors were found in the “vast majority” of cases, the FBI restarted the review, grinding the process to a halt, said a government official who was briefed on the process. The Justice Department objected in January, but a standoff went unresolved until this month.

After more than two years, the review will have addressed about 10 percent of the 2,600 questioned convictions and perhaps two-thirds of questioned death-row cases.

The department is notifying defendants about errors in two more death-penalty cases and in 134 non-capital cases over the next month, and will complete evaluations of 98 other cases by early October, including 14 more death-penalty cases.

No crime lab performed more hair examinations for federal and state agencies than the 10-member FBI unit, which testified in cases nationwide involving murder, rape and other violent felonies.

Although FBI policy has stated since at least the 1970s that a hair association cannot be used as positive identification, like fingerprints, agents regularly testified to the near-certainty of matches.

In reality, there is no accepted research on how often hair from different people may appear the same. The FBI now uses visual hair comparison to rule out someone as a possible source of hair or as a screening step before more accurate DNA testing.

This month, the inspector general reported that inattention and foot-dragging by the Justice Department and the FBI led them to ignore warnings 15 years ago that scientifically unsupported and misleading testimony could have come from more than a single hair examiner among agents discredited in a 1997 inspector general’s report on misconduct at the FBI lab.

The report said that as of 1999, Justice Department officials had enough information to review all hair unit cases — not just those of former agent Michael P. Malone, who was identified as the agent making the most frequent exaggerated testimony.

By 2002, Maureen Killion, then director of enforcement operations, had alerted senior criminal division officials to “the specter that the other examiners in the unit” were as sloppy as Malone, the inspector general said.

“This issue has been raised with the FBI but not resolved to date,” Killion wrote to then-Assistant Attorney General Michael Chertoff and his principal deputy, John C. Keeney, in July 2002, the report said.

Twelve years later, the Florida case shows the continued inadequacy of officials’ response.

Duckett, then a rookie police officer in Mascotte, Fla., was convicted of raping and strangling Teresa McAbee, 11, and dumping her into a lake in 1987.

After a state police examiner was unable to match pubic hair found in the victim’s underwear, prosecutors went to Malone, who testified at trial that there was a “high degree of probability” that the hair came from Duckett.

Such testimony is scientifically invalid, according to the parameters of the current FBI review, because it claims to associate a hair with a single person “to the exclusion of all others.”

The Florida court denied Duckett’s request for a new hearing on Malone’s hair match. The court noted that there was other evidence of Duckett’s guilt and that the FBI had not entirely abandoned visual hair comparison.

Duckett attorney Mary Elizabeth Wells confirmed this week that Duckett’s case was under the FBI’s review. Both Wells and Whitney Ray, a spokeswoman for Florida Attorney General Pam Bondi, said Thursday that parties had not been notified of results, but they otherwise declined to comment.

Duckett’s case was eligible for the 1996 review as a Malone case but was omitted, even though the inspector general stated that “it was important to the integrity of the justice system” that all of Malone’s death-penalty cases be immediately reviewed.

The Justice Department declined to comment on the omission.

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