It was one of the suspects who came forward to help police and prosecutors close a 31-year-old murder case.

Aaron Meyer, 49, pleaded guilty in state court yesterday to manslaughter and first-degree robbery for his role in a 1977 shoot-out at a Moiliili liquor store that killed the store owner.

Meyer was 17 at the time. And the incident has shaped and haunted his life since, said his lawyer, Teri Marshall.

“;And so for him this is, 'I'm stepping up and I'm moving this out,' 'cause he's the impetus of the resolution of this case,”; she said.

Meyer also accepted a 20-year prison term yesterday.

In exchange for his guilty pleas, the state promised to ask the Hawaii Paroling Authority to require Meyer to serve no more than five years of his sentence before he is eligible for parole.

The other defendant in the case, Melvin Kumukau, pleaded guilty to the same charges last week and also accepted a 20-year prison term. However, the state wants Kumukau to serve 10 years before he is eligible for parole.

Marshall said the reason for the disparity is because Meyer was only a teenager at the time, and it was Kumukau, who was 21, who took Meyer to the liquor store to rob store owner Toshio Kawano of his collection of samurai swords.

The state said Kumukau also provided the firearm Meyer used in the attempted robbery and provided the getaway car. Kumukau used a .357 caliber semiautomatic handgun in the shoot-out and kept a loaded shotgun in the car, the state said.

Meyer and Kumukau have previous robbery convictions for which they were sentenced to life in prison. Meyer was released on parole in 1997, and Kumukau was paroled in 2004.

In 2000, Meyer accepted a 10-year prison sentence in a plea agreement with the state for a purse snatching. That was when he told authorities of his role in the 1977 case. Later that year, Kumukau also made a statement to authorities about his role in the case, the state said.

Kawano's son Roy was present for the sentencing of both of his father's assailants. He said the family is pleased to have closure even though neither man was convicted of murder.

Meyer addressed Roy Kawano in court yesterday and apologized to his family.