FBI

The FBI, or Federal Bureau of Investigation, is the investigative arm of the U.S. Department of Justice and the nation’s primary investigative and domestic intelligence agency. First established in 1908, the FBI has often been criticized for violating the civil rights of law-abiding U.S. citizens, even as its role expanded to include domestic and international terrorism.

By the first years of the 20th century, it had become clear that the U.S. Department of Justice lacked sufficient resources to investigate violations of the law across a sprawling, quickly growing nation.

For over 40 years, the FBI crime lab in Quantico had believed that lead alloys used in bullets had unique chemical signatures. It was analyzing the bullets with the goal of matching them chemically, not only to a single batch of ammunition coming out of a factory, but also to a single box of bullets.

The National Academy of Sciences conducted an 18-month independent review of comparative bullet-lead analysis. In 2003, its National Research Council published a report whose conclusions called into question 30 years of FBI testimony.

It found the analytic model used by the FBI for interpreting results was deeply flawed, and the conclusion, that bullet fragments could be matched to a box of ammunition, was so overstated that it was misleading under the rules of evidence. One year later, the FBI decided to stop conducting bullet lead analyses.