The civilian Navy employee who shot his young boss and a co-worker before killing himself in a Crystal City office Friday morning gave colleagues little indication that he was upset with his job, investigators said yesterday.

Ernest J. Cooper Jr., 58, of Waldorf, brandished a .45-caliber handgun after a brief work-related argument, shooting his superior, Nils F. "Fred" Salvesen, 30, and Navy Cmdr. Harry F. Molyneux, 39, before committing suicide.

Salvesen was hit in the neck and lower back and has lost a kidney, according to a family member. Molyneux was shot four times but suffered only flesh wounds. Both were in stable condition at Washington Hospital Center yesterday.

Investigators said they still don't know what provoked Cooper to begin shooting in the 10th-floor office of the Naval Air Systems Command. "There were no signs that led up to it," said a source familiar with the investigation. "There was nothing out of the ordinary with him."

Cooper, a retired Air Force officer working as a logistics specialist, was scheduled to be reassigned at the facility but had not yet been transferred, the source said.

"He had been meeting with his supervisors over the last couple of weeks about the move," the source said. "It didn't seem like it was a big deal."

Employees are not allowed to take guns inside the building, where 3,000 military and civilian employees work. Investigators do not know whether Cooper took the gun to work on Friday or kept it in his office, a Navy spokesman said.

The FBI interviewed Cooper's wife, who would not talk about the case to reporters yesterday.

Neighbors on Cooper's cul-de-sac in Waldorf said he was quiet and enjoyed working on his home computer. Cooper, who they said served in the Air Force for 30 years, becoming a lieutenant colonel, had been stationed at Andrews Air Force Base and went to work in Crystal City in 1986.

"I think it was real difficult for him to go from a military environment to a civilian one," said a neighbor who said she is a close friend of the family. "There just wasn't the same discipline in the workplace."

But the neighbor said she rarely heard him complain about his job.

"He wasn't that type, although it seemed obvious that he had been frustrated for the last few months," she said. Salvesen's father-in-law, Nick Cannistraro, said Salvesen was pulling through "remarkably well" despite taking two rounds at close range.

"He was really lucky," Cannistraro said. "But he's pretty angry about getting shot."