A man accused of killing seven co-workers has been described by prosecutors as a calculating killer who strode through his company's offices Arnold Schwarzenegger-style — an AK-47 in one hand, and a pump-action shotgun in the other.

His lawyer says he's so insane that he believes he killed Adolf Hitler and six Nazi generals.

Michael McDermott, a 43-year-old computer software engineer, is accused of gunning down seven of his colleagues at Edgewater Technology on Dec. 26, 2000.

He testified on Thursday that he left a previous job at a nuclear plant because "I had gone crazy."

"I had an escalating mental illness which eventually led to a suicide attempt," said McDermott, who claimed he was harassed by an ex-girlfriend who worked with him at the Maine Yankee plant. "I cut my wrist open."

McDermott, who has pleaded innocent by reason of insanity, also claimed he was raped several times by a neighbor when he was 8 years old, though it was never reported to police. He said he father later pushed him to join the military after high school.

McDermott believes St. Michael appeared to him 12 days before the shootings and told him he didn't have a soul, but could earn one if he prevented the Holocaust, defense attorney Kevin Reddington told jurors Wednesday.

"This man is insane. As he sits here in front of you now, he is insane," Reddington said.

McDermott planned the slayings in retaliation for the company's plans to withhold his wages to pay $5,600 in back taxes he owed to the IRS, prosecutors said.

The defense contends he is schizophrenic and not criminally responsible for his actions.

McDermott, a burly man with long hair and a bushy beard, sat at the defense table reading a Bible as his lawyer described McDermott's hallucinations and delusions.

Reddington said McDermott brought the guns to the office because "he needed to blow the doors off the bunker when he went to kill Hitler and the six Germans."

"He believes he's killed no one but Hitler and those six German generals," Reddington said.

When police arrived at the Edgewater office in Wakefield moments after the slayings, they found McDermott with the AK-47 and shotgun laying near his feet on the floor.

"I don't speak German," was all he said as he was being arrested, Wakefield police officer George Barry testified Wednesday.

McDermott repeated that statement at the police station.

Reddington had waived his opening statement at the beginning of the trial so he could give it after prosecutors finished their case.

Reddington disputed prosecutors' account that McDermott was angry about the tax issue, saying McDermott had at least $50,000 in his retirement account at the time and was not having financial difficulties. He said McDermott told one psychiatrist that he enjoyed his job at Edgewater and was fond of his co-workers.

McDermott believes St. Michael appeared to him in his work cubicle on Dec. 14, 2000, the same day Edgewater officials told him they had received an IRS order to withhold a large portion of his salary to pay his tax debt.

Reddington told jurors that doctors would testify McDermott suffers from a variety of mental illnesses, including paranoia, depression, schizophrenia and an obscure disorder that makes people think they're dead. He said McDermott has tried to commit suicide at least four times since 1988 and has been hospitalized a number of times.