Hundreds of defendants in prison have been convicted with the help of an FBI forensic tool that was discarded more than two years ago. The FBI lab has yet to alert the affected defendants or courts, even as the window for appealing convictions is closing, an investigation by the Washington Post and CBS News’ “60 Minutes” has found. The science, known as comparative bullet-lead analysis, was first used after President John F. Kennedy’s assassination in 1963. The technique used chemistry to link crime-scene bullets to those possessed by suspects on the theory that each batch of lead had a unique elemental makeup.
In 2004, the National Academy of Sciences concluded that variations in the manufacturing process rendered the FBI’s testimony about the science “unreliable and potentially misleading.” In 2005, the FBI said that although it was ending the technique, it “still firmly supports the scientific foundation of bullet lead analysis.” The government has fought releasing the list of the estimated 2,500 cases over three decades in which it performed the analysis. For most affected prisoners, a two-to-four-year window to appeal their convictions based on new scientific evidence is closing. Dwight Adams, the now-retired FBI lab director who ended the technique, said the government has an obligation to release all the case files, to independently review the expert testimony and to alert courts to any errors that could have affected a conviction.