An Army medic pleaded guilty Tuesday to the shooting death of a fellow soldier in Iraq during a night of heavy drinking.

Spc. Chris Rolan, 23, initially was charged with premeditated murder in the Nov. 16, 2005, death of Pvt. Dylan Paytas, 20, while the two were serving with Fort Benning's 3rd Infantry Brigade in Iraq. He pleaded guilty to unpremeditated murder and other charges under a deal with prosecutors.

The two soldiers had been arguing at Camp Warhorse in Baqouba, Iraq, when Rolan shot Paytas four times with his Army-issue 9mm pistol, according to witness testimony.

Both were assigned a combat team that helped lead the 2003 charge to Baghdad. Rolan, of Albuquerque, was in the 18th month of his second tour in Iraq at the time.

Rolan's court-martial had been set to begin Tuesday morning. Instead, he accepted the agreement to plead guilty to unpremeditated murder, violating a general order against drinking in Iraq, communicating a threat and reckless endangerment.

Officials said he could face life in prison.

In addition to the charges involving Paytas, Rolan had been charged with assaulting and threatening to kill a 25-year-old soldier from Texas during an earlier drinking episode.

Rolan also had been accused of shooting at his roommate, Pvt. Mastermichael Ramsey of Milwaukee, on the night Paytas was killed, but the Army dropped that charge without explanation.

Ramsey had delivered the only eyewitness testimony at Rolan's Article 32 hearing last May.

He testified that he, Rolan and Paytas listened to music, played video games and swilled gin and whiskey on the night of Nov. 15-16, 2005, in violation of Army regulations.

Paytas, of Freedom, Pa., provoked Rolan, and Rolan suggested a wrestling match, Ramsey testified. He said Paytas pinned Rolan and began taunting him. Rolan said, "I'm not going to have Paytas disrespect me," then shot him, Ramsey testified.

Rolan gave a different version in court Tuesday when prompted by the judge to describe what happened.

Rolan said that Paytas and Ramsey arrived at his room with bottles of whisky and gin and that at some point, he blacked out.

When he awoke, he said, "Pvt. Paytas was in my face and Pvt. Ramsey was holding him back. I blacked out again and the next thing I remember is firing."

Rolan said he went to a tactical operations center, still clutching his Beretta pistol, surrendered the gun and turned himself in. Records indicate he may have fired as many as six times, based on shell casings found at the scene. At least three bullets hit Paytas.

Ramsey, meanwhile, has serious legal problems of his own. After leaving the Army Ramsey and three others were charged with murdering a cab driver in Columbus, Ga., near Fort Benning, during a robbery.

John Paytas said Tuesday that his son's death shook his confidence in the Army.

"I didn't want him to come home with his legs blown off or blinded," he said. "I never dreamed another soldier would murder him."