NORTHAMPTON, Mass. (AP) _ A man told police he killed a fellow veteran who tried to prevent him from committing suicide.

''I wish it had been me instead of him,'' said Richard Papineau, 40, who was arraigned as a fugitive Tuesday. He is charged in New Hampshire with murdering Frank Thibeault, who was shot to death in the woods in Winchester, N.H.

Papineau was arrested Monday at Northampton State Hospital, a psychiatric facility where he had been held to determine whether he could stand trial on unrelated charges of assaulting his former wife and girlfriend.

A former Marine who received the Bronze Star in Vietnam, he told police, the Union-News in Springfield and The Recorder in Greenfield that he killed Thibeault.

He identified the victim as a patient at the Veterans Administration Hospital in Northampton and said the killing occurred after the two drove to New Hampshire on April 24, the newspapers said.

''I still wish it had been me instead of him, just like I wish it had been me instead of the guys in Vietnam,'' he said. ''I've been living with them for 22 years. Now there is one more name on that list and I will live with them until I check out.''

Papineau said he was distraught over a restraining order that kept him away from the apartment shared by his girlfriend and his former wife. He said he stopped by the side of the road and, after walking into the woods, put a gun to his head.

''I had the barrel in my face. I was sitting on a rock,'' Papineau said. Thibeault ''came up behind me and said, 'I'm not going to let you do this,' and grabbed me. I kind of freaked. The gun went off and he went down.''

''The next thing I knew, the gun was empty and I was just standing there,'' he said.

Papineau, who was discharged from the Marines in 1968 for ''acute anxiety neurosis,'' has been in and out of mental hospitals since torching a Buddhist shrine in the Berkshire Hills six years ago while on a weekend pass from a VA hospital.

He and two other men said they set the fire to draw attention to a lack of treatment programs for Vietnam veterans.