FORT HOOD, Texas (AP) _ An Army sergeant fatally shot a severely wounded and unarmed Iraqi insurgent after ordering a medic to suffocate him and then tried to cover up the crime, a military prosecutor said Monday as the soldier's court-martial began.

But Sgt. Leonardo Trevino's attorney Richard V. Stevens said soldiers' accounts of that June night in Muqdadiyah, Iraq, are inconsistent and contradict evidence from photos of the insurgent's body. Stevens said the insurgent, whose name U.S. authorities never learned, still posed a threat although he was wounded.

"Sergeant Trevino's actions in that room, in that village were wholly within the rules of engagement," Stevens said during opening statements after the seven-member jury was seated.

Prosecutors were to begin presenting evidence Tuesday morning.

Trevino, of San Antonio, faces up to life in a military prison and a discharge if convicted of premeditated murder and other charges. He has pleaded innocent.

The trial at Fort Hood, where Trevino is a 1st Cavalry Division soldier, is expected to last a week.

Trevino and his "small-kill team" had gone to a dangerous village where insurgents had been making improvised-explosive devices. While perched atop a roof, Trevino and some soldiers saw three men in the street, one with an AK-47, and a gun battle ensued, said Maj. Jacob Wolf, a military prosecutor.

One insurgent was killed and one got away, but the U.S. soldiers followed a blood trail that led to a house where several Iraqis were tending to a man with about two dozen bullet wounds, Wolf said. Trevino ordered the civilians out, and although the bleeding man was on the floor and had a broken arm, soldiers have said Trevino shot him in the abdomen, Wolf said. Soldiers have also said Trevino then told another soldier to place a gun by the insurgent and say that he was armed, ordered a medic to suffocate him and then when that didn't kill the man shot him again.

"He said, 'The Iraqi was wounded but he wouldn't die.' Any emotion was one of satisfaction of accomplishing the mission," Wolf said.

But Stevens said soldiers didn't come forward until two months later after Trevino had disciplined them for various infractions and even kicked two out of his section and that one had written a journal entry about killing Trevino. At first, the soldiers didn't accuse Trevino of murder, Stevens said.

"They had no idea things were going to blow up to the extent that they did," Stevens said.

In two separate military trials in March, his two co-defendants were acquitted on charges stemming from the incident.

Spc. John Torres, the Army medic accused of trying to suffocate the insurgent, was acquitted of attempted premeditated murder and dereliction of duty for failing to provide aid, said Maj. Steven Lamb.

Cpl. Justin Whiteman, accused of placing the pistol by the insurgent's body, was acquitted of accessory after the fact to attempted premeditated murder and with dereliction of duty, Lamb said.

Copyright 2008 The Associated Press.