Fingerprint reliability as evidence will go on trial

PHILADELPHIA -- Ninety-one years after fingerprint evidence was first presented in an American courtroom, its reputation as an infallible forensic tool is under attack in a court challenge that could change how prosecutors try criminal cases.

Today, federal prosecutors will try to persuade U.S. District Judge Louis H. Pollak to reverse his recent decision barring experts from testifying about whether a fingerprint taken from a crime scene matches a defendant. If the judge doesn't change his mind, the decision could change the way forensic evidence is gathered and presented in court.

While prosecutors and some forensic experts say Pollak's ruling could have grave consequences, critics of fingerprint analysis say it's about time the process was reviewed.

"There are a lot of emperors out there testifying who have no clothes," said David L. Faigman of University of California's Hastings College of Law. "Where's the science behind it? Where's the data?"

The ruling, believed to be the first of its kind, involves a death penalty case in which three men are charged with operating a multimillion-dollar drug ring and are linked to four killings.

Lawyers for Carlos Llera-Plaza, Wilfredo Acosta and Victor Rodriguez asked the judge to bar fingerprint evidence. Under Pollak's ruling, experts can testify about and show illustrations of similarities or dissimilarities between "latent" fingerprints from a crime scene and "rolled" fingerprints on file, but they cannot testify that crime scene prints match a defendant's fingerprints.

Citing a 1993 U.S. Supreme Court decision requiring judges to take a more active role in deciding what scientific evidence to admit, Pollak said that, unlike DNA evidence, fingerprint evidence has not been scientifically tested, its error rate has not been calculated, and there are no standards for what constitutes a match.

Prosecutors said in court documents that Pollak's opinion "would have grave consequences."

"It would deprive the government of vital evidence in this case, in which latent fingerprints directly link defendants to heinous murders," court documents stated.