A gun collector who introduced several weapons into sexual play with two other men contends the weapons were intended to fulfill a sexual fantasy. Instead, a lethal combination of drugs, extreme sex and Russian roulette has put him on trial for manslaughter.

Both the defense and prosecutors say there was no intention to kill. But prosecutors say defendant Bruce Lavallee-Davidson, a farmer from Skowhegan, was responsible for ensuring his gun wasn't loaded when it was being handled.

The trial in Portland, the state's largest city, has shed light on a dungeon in a home in neighboring South Portland filled with sexual toys that three men used as a drug-fueled escape from reality. But Assistant Attorney General Lisa Marchese says the focus should be on the handling of the gun — not the sexual acts in the victim's basement.

"You never point a loaded gun at someone's head," Marchese said after resting her case Tuesday, emphasizing it's the responsibility of the person holding the revolver to ensure the chamber is empty. "You don't point a gun and pull the trigger unless you're 100 percent sure."

The bespectacled Lavallee-Davidson, with closely cropped gray hair and a goatee and dressed in a sport coat and khakis, gave the appearance of a college professor as he sat quietly in court, where closing arguments were anticipated Wednesday. Before becoming an organic farmer, he was a technology administrator for Maine Central Institute, a prep school.

The Dartmouth College graduate was in a committed relationship when he testified in favor of keeping Maine's now-overturned gay marriage law at a public hearing, four days after the discovery of the body of 50-year-old Fred Wilson and a couple of weeks before he was indicted.

The fatal shooting happened after the three men had been smoking pot, drinking beer, huffing aerosol inhalants and having sex over a 12-hour period in the basement of Wilson's Colonial home in a middle-class neighborhood two blocks from the ocean.

One of the participants, James Pombriant, 65, says he first thought the others were playing a sick joke on him when he saw the flash of a handgun early on April 18, 2009.

Pombriant, who was engaged in a sex act with the victim when the shot rang out, says there was a moment of silence before Lavallee-Davidson said, "I think I killed him."

Lavallee-Davidson, 50, contends the killing was an accident.

One of his lawyers, Mike Whipple, says his client checked three times over the course of the night to make sure the .44-caliber Rossi revolver wasn't loaded. Whipple contends it's likely Wilson loaded the gun while Lavallee-Davidson briefly stepped away to use the bathroom.

When Lavallee-Davidson returned, Wilson asked him to put the gun to his head and pull the trigger to intensify his pleasure, the defense contends. On the first try, there was a click when Lavallee-Davidson pulled the trigger. Wilson asked him to do it again, and there was a flash, the defense says.

After the shooting, Pombriant, of Auburn, and Lavallee-Davidson left Wilson's body behind in the home over the course of the day before Pombriant called police that night. Police recovered the handgun used in the killing and a .12-gauge Mossberg shotgun that Lavallee-Davidson had taken to Wilson's home for the sex games.

Deputy Attorney General Bill Stokes doesn't dispute that the killing was unintended. Nonetheless, he said, the circumstances fit the legal definition of manslaughter, which means to cause death through recklessness or criminal negligence. Manslaughter carries a penalty of up 30 years in prison.