DETROIT – If you watch crime shows you know all about fingerprints. Police find a print, run it through the computer, and arrest the bad guy.
However, a local lawyer says innocent people are paying the price because juries believe too much of what they see on TV—and the science of fingerprinting isn't quite as cut-and-dried as it would seem.
When it comes to gathering finger prints, few do it better than the Troy Police Department's evidence technicians. They are highly trained and able to find prints on all sorts of objects and surfaces.
"If you look at your fingerprints, people have different patterns," said Joe Mouch, a fingerprint expert with the Troy Police. "Some are loops, some are swirls, some have arches. They all have ridges in them that stop and start, change directions, and those stops and starts are one of the big things they look for, as far as identifying each unique fingerprint."
Troy's technicians are widely regarded as experts in the field, and when they have a match it's usually considered as good as gold in the courtroom.
It's still one of the most valuable tools used, just because the uniqueness of prints," said Tony Cascioli, another Troy Police fingerprint expert. "[It's r]eally hard to dispute that your print was there."
If you're like most people, you've probably come to believe a fingerprint at the scene of a crime is good enough to convict a suspect.
"No two people that we are aware of, at least, have the same fingerprints," said Mouch. "Not even identical twins."
However, Neil Rockind, local defense attorney, says fingerprint evidence is far from foolproof.
"Fingerprint evidence is powerful," Rockind said. "It's compelling, but it's also dangerous."
His concern is that a print is only as good as the person examining them, and he insists mistakes do happen.
He points to an internal evaluation of qualified examiners as evidence that fingerprint evidence should be considered with a healthy amount of skepticism.
"Twenty percent wrongly identified or misidentified a person in a fictitious case," he said.
Rockind believes jurors often overvalue fingerprint evidence, and even the experts will tell you that real life evidence isn't often like it's presented in crime dramas.
Criminals rarely leave perfect prints. They can be smudged and smeared, and usually there is rarely full print. Evidence technicians often use partial prints to help investigators and prosecutors make a case.
Police and prosecutors say, when they have a good print and a good technician, they are completely confident they can identify the guilty party. Still, Rockind believes when mistakes are made, innocent people can be wrongly convicted on bad fingerprint evidence.
"That happened to an attorney named Branden Mayfield who was ID'ed by several FBI fingerprint experts as being the person that left the print in the Madrid Spain Bombing," he explained.
In that 2004 case, the technicians that got it wrong and were supposed to be among the best of the best.
"You had three trained FBI agents, all certified as experts, all who are qualified by Department of Justice as fingerprint examiners and all who agreed that Mayfield left the print," said Rockind.
The mistake proved costly for taxpayers as the FBI ultimately had to apologize and Mayfield was awarded two million dollars in a civil suit.
Experts say eventually police and prosecutors will rely less on fingerprints and more on DNA. However, DNA collection is expensive and, because of backlogs at crime labs, it takes much too long to get results.
For now law enforcement—and juries—must rely on fingerprints to identify guilty parties, for better or worse.