Weighing Fingerprints As Forensic Evidence

It turns out a partial, distorted print, like the one the FBI had, often yields multiple potential matches. In fact, when the Madrid print was put into the government's automated system, 20 different prints with similarities came up, including Mayfield's. After the first FBI examiner mistakenly matched the print to Mayfield, the other two confirmed it.

The Bureau has since promised "procedural reforms," but Kent says he isn't buying it.

"The problem is, how many Mayfields are there?" he said. "If the best, by their admission, can make such a glaring error in a high-profile case when they knew the world was watching, what is happening in the counties, in the countryside, in areas where we don't, quote, 'have the best of the best?'"

But examiner Glen Langenburg believes this case is not the norm:

"I'm always concerned if an innocent person has to go to jail, of course. But I not concerned it's a rampant issue, that this is happening every single day, that people are [wrongly] going to jail on fingerprint evidence. I just don't believe it."

Brandon Mayfield was released and received a public apology from the FBI - along with a $2 million legal settlement.

"I was looking at much more severe consequences, and had no idea and felt totally helpless and had no idea how my family was gonna take care of themselves, or what's going to become of me," he said.

"I just want to leave it in the past," Mona Mayfield said, "but of course, it's gonna affect me, it's always gonna affect me. I mean, even for my children, it's always going to affect them for the rest of their lives."

As for Brian Keith Rose in Maryland, he's still facing murder charges. The case has now been moved to federal court where the judge is expected to allow in the fingerprint evidence.

"Mr. Mayfield is not an aberration," Kent said. "Mr. Mayfield is a public face of many people in jail. It leaves me sleepless, quite candidly, because in fact it not that it just scares me to death, it's evidence that they use to put people to death."