Testing the chemical composition of bullets was thought to be a way to match bullets to their source, allowing the FBI to link bullets to suspects, much as it uses blood type to link evidence to an individual. Accepted as evidence for 30 years in criminal cases, bullet-lead analysis led to many convictions. However, scientific studies starting in 2001 have shown that FBI courtroom testimony about bullet lead is flawed:
SOURCE: National Academy of Sciences report, FBI documents, research of former FBI metallurgist William Tobin | By Laura Stanton The Washington Post - November 17, 2007
FBI's Forensic Test Full of Holes Article | Hundreds of defendants sitting in prisons nationwide have been convicted with the help of an FBI forensic tool that was discarded more than two years ago. But the FBI lab has yet to take steps to alert the affected defendants or courts, even as the window for appealing convictions is closing, a j...