Updated

Lance Cpl. Patrick Malone was relaxing on his bunk at an Iraqi combat base when a direct superior interrupted his late-night movie.

It was time for a game Marines sometimes play to build confidence in colleagues: Point a gun at a comrade and ask, "Do you trust me?"

Cpl. Mathew Nelson raised his weapon — and the 9 mm pistol went off, striking Malone in the head. The higher-ranking Marine rushed to the wounded man's side and tried to perform CPR, but Malone was mortally wounded.

The game, which has cropped up in barracks across Iraq and Afghanistan, is supposed to make a serviceman feel comfortable enough with a comrade that he would stare into the other Marine's gun barrel. But it violates the military's basic weapon-safety rules.

"I can't believe the Marines, these professional soldiers, are playing these games," said Damian Malone, father of the slain 21-year-old.

The younger Malone "was willing to put his life on the line every day, and when he came back to his unit he wasn't supposed to have to worry about his safety."

On Thursday, Nelson pleaded guilty to involuntary manslaughter and seven counts of reckless endangerment for the shooting at Combat Outpost Viking in Anbar province just before midnight on March 9.

Nelson, 25, of Dearborn Heights, Mich., was sentenced Thursday to eight years in Camp Lejeune's brig, demoted to the lowest rank in the Marines and given a bad-conduct discharge.

"From the beginning, my client has been eaten up with remorse," said Vaughan Taylor, a civilian lawyer who represented Nelson.

Taylor said the two Marines had finished the trust game, and Nelson turned away. His subordinate, from Ocala, Fla., called out to tell him he was going to attend to the unit's vehicles outside.

The corporal turned back, pulling the trigger on the weapon he didn't know was loaded, Taylor said.

The game typically begins when one service member partially inserts a bullet magazine into the handle of a pistol and pretends to pull back the gun's slide to make it appear that the weapon is ready to fire.

He then points the weapon at a fellow service member before either pulling the trigger or lowering the gun. Typically, even if he pulls the trigger the weapon will not discharge because a bullet is not in the chamber.

"When you give high-powered weapons to young men, once in a while bad things are going to happen," said Gary Solis, a retired Marine lieutenant colonel and attorney who teaches on the law of armed conflict at West Point and Georgetown.

"You have young men, bored, killing time with a gun. That's not a good mix," Solis said. "I don't think the Marines have any corner on this. I think it happens in the civilian community as well."

The Marine Corps Times reported this week that the game had similar deadly end in 2007, when a Kentucky Army National Guardsman shot and killed a fellow soldier.

The guardsman who fired the fatal shot later said he learned to play from other members of his unit while deployed to Iraq in 2006.

Damian Malone believes his son's unit hid the game from their superiors and claimed they were building trust within the team. But the practice amounts to a form of hazing that should be wiped out of the military, he said.

Patrick Malone joined the Marines in 2007 after a year at the University of South Florida and another year at a community college closer to home. He went to Iraq in October 2008 as an anti-tank missileman.

"I guess there's a little closure on this because you meet who this guy was and you see what happened," Damian Malone said after attending the court-martial with his wife and other family members. "Now we want to expose this game, wherever it is."