I can remember this being used in TV shows as the basis for the prosecutions case; I can imagine this will have pretty significant impact on quite a few case.
The science, called bullet lead analysis, was used by the FBI for 40 years in thousands of cases, and some of the people it helped put in jail may be innocent.
Lee Wayne Hunt says he's been behind bars for over 22 years and 6 months, and maintains he's an innocent man. "What I've said from the word get go that I ain't -- never killed nobody. I didn't have nothing to do with this," Hunt tells Kroft.
Hunt was convicted in 1986 of murdering two people in Fayetteville, N.C., based on the testimony of two questionable witnesses and what turned out to be erroneous ballistics testimony from the FBI lab.
For years, the FBI believed that lead in bullets had unique chemical signatures, and that by breaking them down and analyzing them, it was possible to match bullets, not only to a single batch of ammunition coming out of a factory, but to a single box of bullets. And that is what the FBI did in the case of Lee Wayne Hunt, tying a bullet fragment found where the murders took place to a box of bullets the prosecutors linked to Hunt.
Tobin says the Quantico lab was the only place in the country that did bullet lead analysis, and the assertion that you could actually match a bullet fragment to a specific batch or box of bullets went unchallenged for 40 years -- until Tobin retired in 1998 and decided to do his own study, discovering that the basic premise had never actually been scientifically tested.
"FBI lab personnel testified that you could match these fragments to this bullet," Kroft remarks.
"Yes, that's correct," Tobin says.
Asked what he found out, Tobin tells Kroft, "It hadn't been based on science at all, but rather had been based on subjective belief for over four decades."