So much for beyond a reasonable doubt. According to a new report by the FBI, the bureau’s forensic experts have made numerous mistakes in linking evidence to defendants in death penalty cases. The report noted 27 instances of incorrect testimony that helped convict defendants in death penalty cases.

An unprecedented federal review of old criminal cases has uncovered as many as 27 death penalty convictions in which FBI forensic experts may have mistakenly linked defendants to crimes with exaggerated scientific testimony, U.S. officials said…

It is not known how many of the cases involve errors, how many led to wrongful convictions or how many mistakes may now jeopardize valid convictions. Those questions will be explored as the review continues.

The full extent of the impact of the study is still unknown, but the report already led to a stay of execution in Mississippi last May. There may be more reviews and stays on the way.

The FBI and Justice Department worked with the Innocence Project and the National Association of Criminal Defense Lawyers (NACDL) in authoring the review.

Under terms finalized with the groups last month, the Justice Department will notify prosecutors and convicted defendants or defense attorneys if an internal review panel or the two external groups find that FBI examiners “exceeded the limits of science” when they claimed to link crime scene hair to defendants in reports or testimony.

If so, the department will assist the class of prisoners in unprecedented ways, including waiving statutes of limitations and other federal rules that since 1996 have restricted post-conviction appeals. The FBI also will test DNA evidence if sought by a judge or prosecutor.

Though there are only 27 cases listed even more could be influenced by the review. The Innocence Project has said that one of the criteria for faulty hair evidence has been met in 2000 cases. The implications of the review could be extensive.

America is one of the few developed countries that still has the death penalty. Now, upon learning of faulty evidence in many death penalty convictions, perhaps it is time to rethink the death penalty.

Photo by KimChee under public domain.