Three people convicted of murder have been released from prison because their cases were tainted by a discredited theory that bullets found at a crime scene could be linked to bullets found in possession of suspects, reports the Associated Press. Nearly five years after the FBI abandoned its comparative bullet lead analysis, the FBI has yet to complete its review of nearly 2,500 cases where such evidence was used to investigate a case.
The agency has found 187 cases where FBI experts provided testimony using comparative bullet lead analysis evidence. It has notified prosecutors in those cases where testimony from its experts “exceeds the limits of the science and cannot be supported by the FBI.” Three convictions – that of a Colorado man who served 12 years in prison for a double slaying, a Florida man who served 10 years after being convicted of killing his wife, and an Oregon man convicted of a triple slaying – have recently been overturned. All three are now free. Comparative bullet lead analysis was based on a theory that lead bullets pick up trace elements such as copper, antimony, arsenic, bismuth, and silver during manufacturing. When the soft metal is shaped into bullets and packaged, bullets in the same box would contain similar amounts of the trace elements, the theory said.