Eyewitness testimony has been a magnet for criticism that such evidence is unreliable and prone to error, which has led to convictions of potentially innocent people.

Courts can bar eyewitness evidence in the police are found to have manipulated a witness into picking a particular suspect. But a case that was argued before the U.S. Supreme Court on Wednesday could expand that authority to any situation in which eyewitness testimony is unreliable.

For New Hampshire resident Barion Perry, eyewitness testimony in part landed him a conviction and jail time for breaking into a car.

In the early morning hours of Aug. 18, 2008, a woman in an apartment told a police officer that a tall black man was the culprit. When pressed for more details, she pointed out Perry, who, at the time, was standing in the building's parking lot with another police officer, from her apartment.

She could offer no other identifying details, the culprit. Later, she was unable to pick him out of a photo array later at the police station.

Perry's attorney failed to suppress the eyewitness testimony. The case went to the New Hampshire Supreme Court, which ruled against Perry because there was no improper police conduct.

Due process safeguards should not be construed to allow the state to claim the absence of police involvement as justification for the admissibility of identification evidence which poses a very substantial risk of misidentification, Perry's lawyer wrote in his brief to the Supreme Court.

Eyewitness evidence has been blamed for 75 percent of wrongful convictions later overturned by DNA evidence, according to the Innocence Project.

Justice Elena Kagan recognized the evidence challenging the reliability of eyewitness testimony, but questioned setting a standard for other kinds of evidence.

I understand you have very good empirical evidence which should lead us all to wonder about the reliability of eyewitness testimony, Kagan said. I'm just suggesting that Eyewitness testimony is not the only kind of testimony which people can do studies on and find that it's more unreliable than you would think.

Justice Ruth Bader Ginsburg asked Perry's attorney, public defender Richard Guerriero, about the current safeguards for defendants.

You can say something about it in your summation to the jury, Ginsburg said. You have the evidence rule that says if prejudicial value outweighs probative value that the judge can say, I'm not going to let it in. Why aren't all those safeguards enough?

New Hampshire Attorney General Michael Delaney argued that the Due Process Clause of the Constitution concern police influence on suspects, essentially stacking the deck, putting their thumb on the scale and skewing the fact-finding process.

New Hampshire is supported by 29 states and the Obama administration. Arguing for the administration, U.S. Solicitor General of Donald Verrilli said that a decision in favor of Perry would open the door for challenges to other types of disputed evidence.

If the court were to adopt a special rule or eyewitness identification evidence not obtained by the police, Verrilli wrote, no doubt criminal defendants would argue that other types of potentially unreliable evidence--such as confidential informant testimony or testimony of a cooperating co-conspirator--also raise due process concerns.

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