Kansas City, Mo. ? A man accused of killing a Navy shipmate in the Philippines in 1968 pleaded guilty Thursday to a reduced charge of voluntary manslaughter.

The case against Michael E. LeBrun, 60, of Greenwood, Mo., developed after the slain man’s sister pressed the Navy to reopen the case. Originally, investigators concluded the victim, Navy Ensign Andrew L. Muns, stole money from the ship and deserted.

“Both parents and a brother died being told their son was a thief and a quitter,” U.S. Atty. Todd Graves said after the hearing. “The honor of Ensign Muns is restored today.”

LeBrun had been charged with first-degree murder and his trial was scheduled to start Monday in U.S. District Court. He could have faced life in prison without parole if convicted on that charge, but his plea agreement with the government calls for a sentence of up to 10 years.

Muns, 24, disappeared in January 1968 while the USS Cacapon was anchored at Subic Bay in the Philippines. About $8,600 was discovered to be missing from the ship’s disbursement office, and the Navy decided that Muns, the ship’s payroll officer, must have taken the money and deserted.

Thirty years later, Muns’ sister persuaded the cold-case unit of the Naval Criminal Investigation Service to take another look, and the new investigation led them to LeBrun in 2000.

LeBrun, who was a supply clerk on the ship, had sought to keep the government from using a statement in which he told the investigators that he strangled Muns after the ensign caught him stealing money from a safe. He said he put the body and the money inside a tank of fuel oil.

Last week, U.S. District Judge Dean Whipple ruled the videotaped confession could be used as evidence at the trial, saying he was satisfied that prosecutors had enough evidence to independently corroborate it. Appearing before Whipple on Thursday, LeBrun entered his plea to the lesser charge.

“We still feel the confession was not a voluntary confession,” said LeBrun’s attorney, Glenn E. Bradford. “We took that as far as we could possibly go.”

The confession became a contentious issue because the investigators did not advise LeBrun of his Miranda rights after asking him for a voluntary statement. Court records show they promised he would not be prosecuted if he confessed to manslaughter, because the statute of limitations on that crime had run out.

After two federal judges in Kansas City ruled investigators coerced the confession and violated LeBrun’s Miranda rights, an appeals panel ruled the confession could not be used.

But after a hearing in 2003, the full 8th U.S. Circuit Court of Appeals ruled the confession admissible, and the U.S. Supreme Court later declined to take the case.

Bradford then tried another approach, arguing that a rule that a person cannot be convicted only on the basis of an uncorroborated confession applied to the case.

At a hearing before Whipple last week, Deputy U.S. Atty. Matt Whitworth argued that Muns’ disappearance is consistent with LeBrun’s confession, as was the missing $8,600.