WISCASSET – A man accused of gunning down seven colleagues at a software company near Boston worked for six years at the Maine Yankee nuclear power plant, and former co-workers were shocked to hear about the killing spree.

Michael McDermott was a U.S. Navy veteran who worked at the plant in the 1980s, and he was remembered as a fairly normal person.

“He wasn’t necessarily outgoing, but he was a sociable enough, amiable fellow,” said John Harvey, who was in maintenance for 25 years at the nuclear power plant, which was closed in 1997.

John McArdle, who served with McDermott on the USS Narwhal, a submarine, described him as an average guy and a competent sailor. “He was a good sailor, he did his job,” said McArdle of Plaistow, N.H.

McArdle last saw McDermott in 1987 when McDermott was working for Maine Yankee. McArdle was working for Yankee Atomic Electric Co.’s nuclear services division and was serving as a consultant to Maine Yankee.

He was at the company’s office in Augusta one day when he saw McDermott.

“He said, ‘Hey, John Henry, how are you?”‘ recalled McArdle. The two reminisced for a while and McDermott explained he was working for Maine Yankee.

About 10 years later, in 1997, McDermott posted a notice on a Web site for the USS Narwhal, remembering the encounter:

In the message, McDermott said he was doing research and development for Duracell batteries. He said he had married a childhood friend, and that the marriage lasted 31/2 years before his wife left him.

Eric Howes, a spokesman for Maine Yankee, which is in the process of decommissioning, said there was a Michael McDermott who worked at the plant from 1982 to 1988 as an auxiliary power plant operator.

Howes couldn’t confirm that McDermott was the same man charged with seven counts of murder, but McArdle is certain it’s the same person.

He remembered him from the submarine and from the encounter in Augusta. He also remembers McDermott’s nickname – “Mucko” – which is listed as part of McDermott’s e-mail address on the Web site about the submarine.

“It’s sad,” McArdle said. “I hear people saying they ought to kill him. … If this had been somebody else I did not have a personal knowledge of, I’d probably be saying the same thing.”

McArdle said he did not know what happened between McDermott’s Navy stint and the rampage in Wakefield, Mass.

“Something happened, and sadly … the results of this are seven people that aren’t coming home again,” he said.