NEW YORK, Aug 26 (Reuters) - A New Jersey Supreme Court decision ordering sweeping changes to the state's eye-witness identification system could trigger legal challenges and clog local courts.

The 142-page opinion, written by New Jersey Supreme Court Chief Justice Stuart Rabner, highlights a growing awareness of how memory flaws and mis-identification of defendants can play out in the criminal justice system -- sometimes leading to wrongful convictions.

The decision was hailed by criminal justice groups such as the Innocence Project. Though the court's ruling has no binding influence outside of New Jersey, other state courts could take the opinion into consideration, said Kip Cornwell, a law professor at Seton Hall University in Newark.

CRITICISM FROM DEFENSE BAR

States including California and New Mexico have grappled with reforming their witness identification guidelines, as the advent of new social science data has prompted criticism from criminal defense bar on mis-identifications.

A task force in New York convened by New York State Chief Judge Jonathan Lippman made several recommendations earlier this year to police groups and prosecutors about witness identification, as well as to judges about juror instructions. The state's district attorneys association also developed new guidelines about photo identifications and lineups in 2010.

NUDGED BY A DETECTIVE

Wednesday's New Jersey Supreme Court opinion, State v. Larry R. Henderson, stemmed from a case in which an eye-witness testimony was the primary evidence in a homicide trial. Before the trial, the witness said a detective was "nudging" him to identify the defendant.

The trial court admitted the eye witness's identification, and while Henderson was acquitted of the most serious murder charges, he was convicted of reckless manslaughter, aggravated assault and weapons possessions charges. He was sentenced to 11 years in prison.

The state supreme court decision calls on the New Jersey courts to take new measures to address doubts surrounding the reliability of eye-witnesses who identify criminal defendants.

Judges must consider factors when determining a witness's reliability, such as race, stress and timing of a positive identification, the New Jersey Supreme Court said.

The opinion goes far beyond the requirements of a 1977 U.S. Supreme Court opinion, Manson v Brathwite, the seminal high court opinion on witness identification, said Cornwell, the Seton Hall professor.

"This is a very comprehensive decision that really methodically evaluates the totality of scientific evidence that is available at this point in time," he said.

CLOGGING THE COURTS?

The decision will likely trigger a host of litigation as trial and appellate courts sort out how to implement the Supreme Court's mandate, said David Kiefer, a partner at law firm SNR Denton.

"It will have the trial court judges scratching their heads about how to implement the new hearings, and how to rule," said Kiefer, a former prosecutor in New Jersey.

For some victims' rights advocates an increase in pretrial hearings raises the prospect of further clogging the state's courts, from complex criminal matters to lower-level offenses such as drunk-driving.

"Adding more burdens to the courts isn't going to increase the efficiency of the justice process," said Richard Pompelio, executive director of New Jersey Crime Victims' Law Center. "What does it mean for the victims? It means they get distanced even further from some kind of justice result."

The Supreme Court seemed to take the practical implications of its ruling into account, requiring hearings only when defendants can show there is a substantial likelihood of mis-identification.

The New Jersey attorney general's office praised the court for not requiring systemic change, while the New Jersey public defender who represented Henderson said he was gratified by the opinion.

The ruling's mandates will take effect 30 days after the New Jersey Supreme Court approves new model juror instructions on witness identification.

(Reporting by Carlyn Kolker, additional reporting by Joseph Ax)

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