The FBI has stopped using bullet-lead matching, a forensic technique used for at least 25 years that had been criticized as inaccurate and misleading, the Los Angeles Times reports. The bureau suspended its use last year after a report by the National Research Council found the technique could be “seriously misleading” and “objectionable.” The council finding called into question FBI testimony in hundreds of cases involving murder and other serious crimes. “It’s a victory for good sense and good science over the kind of nonsense the FBI was representing in court,” said William Thompson, a professor of law and criminology at University of California-Irvine.
The FBI will alert about 300 courts and prosecutors that since 1996 had received bullet-lead laboratory reports indicating positive results. The bureau estimated it had conducted 2,500 bullet-lead examinations for federal, state, local and foreign cases since the early 1980s. In bullet-lead analysis, crime-scene bullets are tested for trace elements, such as antimony, silver and tin. Examiners compared those elements to levels found in bullets in a suspect’s possession. FBI Laboratory Director Dwight Adams said the agency, after conducting its own 14-month evaluation, concluded that the manufacturing and distribution of bullets was too variable to make the matching reliable. A Los Angeles Times investigation in 2003 suggested the FBI might have exaggerated the scientific validity of bullet-lead matching.