The conviction of a car-stereo thief in Nashua was upheld by the U.S. Supreme Court on Wednesday, the first time in 40 years that the highest court in the land has ruled on a New Hampshire criminal case.

The 8-1 ruling in Perry vs. New Hampshire settles a growing dispute in appellate courts over how trial courts should treat eyewitness identifications that had been unintentionally influenced by police, said New Hampshire Attorney General Michael Delaney, who argued the case.

“More than anything, it was a humbling experience to participate in our justice system at the highest level,” said Delaney, who argued the case on Nov. 2 in Washington, D.C.

Delaney said he spent the month of October in intense preparation, including mock hearings, and received invaluable help from his team of appellate lawyers.

He noted that former Attorney General Kelly Ayotte, now a U.S. senator, attended the hearing. Ayotte had argued a case before the Supreme Court in 2005.

New Hampshire Public Defender Richard Guerriero argued on behalf of the defendant, Barion Perry. The Union Leader was unable to reach Guerriero Friday.

While the case dealt with a petty crime, its implications were significant enough that it drew briefs from 30 state attorneys general, the U.S. solicitor general, the Innocence Network and organizations representing district attorneys, defense lawyers and psychologists.

In the early morning of Aug. 15, 2008, Nashua police stopped Perry at an apartment building parking lot. A car window was shattered, a metal bat was on the ground, Perry held two car-stereo amplifiers.

Police questioned Perry. Then one officer stayed with him while another climbed to a fourth-floor apartment to speak to Nubio Blandon.

Blandon told police she saw an African-American man roaming the parking lot, looking at cars and eventually entering her neighbor's car. When police asked her for a specific description, she looked out her kitchen window, pointed to Perry, who was standing next to a police officer, and said it was him. Police then arrested him.

Later, Blandon could not pick him out of a photo lineup. She testified at trial, however, and a jury convicted Perry of theft but cleared him of criminal mischief.

The issue hinged on the presence of a police officer next to Perry when Blandon identified him. His defense lawyers said that the officer's presence suggested Perry was the thief, and a judge should have considered and ruled pretrial whether the jury should have heard Blandon's eyewitness identification.

Not so, said the trial court, the New Hampshire Supreme Court and now the U.S. Supreme Court.

In previous decisions, the high court has ruled that a judge must consider the admissibility of such evidence when suggestive behavior was intentional on the part of police.

With Wednesday's ruling, the court says that a jury gets to decide on the credibility of eyewitness identification when police conduct is unintentional.

“(Perry's) position would open the door to judicial preview, under the banner of due process, of most, if not all, eyewitness identification,” read the majority opinion, written by Ruth Bader Ginsburg.

“To embrace Perry's view would thus entail a vast enlargement of the reach of due process as a constraint on the admission of evidence.”

The judicial review, she wrote, serves as a deterrent against intentional police behavior that is suggestive. One such example would be for police to instruct participants in a lineup to try on an article of clothing that only fits the suspect.

Delaney said justices peppered him and Guerriero with questions, and Justice Sonia Sotomayor was by far the hardest on him.

In her dissent, Sotomayor said the majority puts too much emphasis on the motives of police.

Research indicates that eyewitness misidentification is the single greatest cause of false convictions in the country, she said.

“Presumably, in the majority's view, had the police asked Blandon to move to the window to identify the perpetrator, that could have made all the difference,” she wrote.

As for Perry, 12 days after the Supreme Court hearing in November, Nashua police arrested him and charged him with breaking into a home and stealing $1,500 worth of property.