PORTLAND – Maine’s highest court was evenly divided on a key issue Tuesday as it upheld a Lewiston man’s conviction and sentence in the knife slaying of a Bates College student during a street brawl a few blocks from campus nearly five years ago.

The Supreme Judicial Court rejected Brandon Thongsavanh’s contention that the trial judge erred by failing to instruct jurors that they could find him guilty of manslaughter rather than murder.

Because the six justices who heard the case were split evenly on whether the evidence could support a manslaughter verdict, the conviction was upheld. Justice Jon Levy had recused himself for an unexplained reason, and the opinion did not provide a breakdown on how the other justices lined up.

The court was unanimous in rejecting Thongsavanh’s broader argument that the state law governing depraved indifference murder was unconstitutionally vague.

Thongsavanh, 23, was twice found guilty of murdering Morgan McDuffee, the 22-year-old captain of the Bates lacrosse team, in the early morning on March 3, 2002, but the supreme court overturned his first conviction because a reference to a profane T-shirt he was wearing at the time of the killing may have prejudiced the jury.

On Tuesday, the court denied Thongsavanh’s appeal of his 58-year prison sentence. It noted various mitigating factors, such as his youth and lack of a criminal record, but said they were more than offset by his lack of remorse, perjury, substance abuse, violence in prison and “psychological evaluations that indicate a lack of social conscience.”

Murder in Maine is punishable by a minimum of 25 years and a maximum of life. Thongsavanh’s basis sentence was set at 42 years, but he argued in the appeal that it should have been lower because it followed his spontaneous involvement in a street brawl that he did not instigate.

The court, however, pointed to “the senselessness and unprovoked violence of the crime, and the fact that McDuffee did not die at the scene of the crime and was aware of his impending death.”

Deputy Attorney General William Stokes said he was pleased at the court’s ruling, although he recognized that some of the justices were troubled by the lack of a manslaughter instruction.

“Obviously, this is the second jury conviction, and from our standpoint and the standpoint of the family it’s time to move forward and move beyond the trial phase and feel comfortable that this conviction will stand,” he said.

Stokes, who heads the state’s criminal division, said that if the ruling had gone the other way, prosecutors would have no choice but to try the case again, even though it would be harder to line up witnesses and muster evidence.

“You don’t really have any choice in the matter; you’d grin and bear it the best you can and try to do it a third time,” he said.

One of Thongsavanh’s lawyers, David Van Dyke, said he had not reviewed the 22-page opinion in depth and had yet to notify his client that his appeal had been denied.

But Van Dyke suggested that one approach under consideration would be to seek a U.S. Supreme Court review of the constitutionality of the depraved indifference law. “There may be federal avenues” Thongsavanh can pursue, the lawyer said.

Thongsavanh’s retrial in October 2005 ended when the jury returned a murder verdict after 13 hours of deliberations over three days. His subsequent sentence was identical to the one imposed after his first trial.

The appeal focused on the trial judge’s refusal to grant Thongsavanh’s request for a jury instruction on manslaughter, which had been given in the first trial. The defense argued that there was no evidence of motive and the defendant may have grabbed a knife and rushed into the brawling crowd without any deliberate intent to kill anyone.

The prosecution argued that because McDuffee suffered five separate stab wounds, there was no basis for a manslaughter option.

The justices unanimously rejected Thongsavanh’s argument that juries must be instructed on criminally negligent manslaughter in all cases of depraved indifference murder. Instead, the court cited a provision of the law that said such instructions are required only if, “on the basis of the evidence there [was] a rational basis for finding the defendant guilty of that lesser included offense.”

That set the stage for the court’s ruling on the key issue of whether the evidence at the trial was sufficient to generate a manslaughter instruction. Because the court was evenly divided, the appeal was denied.