A US Army staff sergeant has pleaded guilty to assaulting unarmed Afghan farmers as part of a deal which requires him to give evidence against other soldiers.
Five of 12 soldiers on trial are accused of premeditated murder. Several are alleged to have collected severed fingers and other human remains as war trophies in Afghanistan.
Robert Stevens (25) admitted opening fire on two Afghan men for no apparent reason, saying he and other soldiers were acting on orders from a squad leader during a patrol in March.
Army Judge Lt Col Kwasi Hawks sentenced the army medic was sentenced to nine months in prison and demoted him to the army's lowest rank.
The charge of aggravated assault with a dangerous weapon was the most serious of four offences to which Stevens pleaded guilty at Joint Base Lewis-McChord near Tacoma, Washington.
The case began as an investigation into hashish use in an infantry unit then known as the 5th Stryker Brigade. But it has grown into the most serious prosecution of alleged atrocities by US military personnel since the war began in late 2001.
A potentially explosive aspect of the case is the existence of dozens of grisly photographs that four of the troops are accused of having taken of war dead, some of them showing US soldiers posing with the corpses.
The images, so far sealed from public view, have drawn comparisons with pictures of Iraqi prisoners taken by US military personnel at the Abu Ghraib prison in Iraq in 2004.
Stevens, though not regarded as one of the leading figures in the case, was court-martialed first because he waived his rights to a preliminary proceeding. As part of the deal, military prosecutors said they would grant Stevens immunity from further charges in exchange for his testimony against the 11 others.
"It's the right thing to do and I'm going to do it," he said later in the hearing, as he took the witness stand for 45 minutes of questioning by his own lawyer.
Asked by the presiding officer why he pleaded guilty to charges that carry a possible maximum penalty of nearly 20 years in prison, Stevens said quietly: "I performed those actions and I did it, your honour."
The three other charges against Stevens were wrongfully tossing a grenade out of his vehicle during a convoy last spring, making false statements to military investigators and dereliction of duty.
He pleaded not guilty to a fifth charge, conspiracy to commit assault, stemming from the shooting incident involving two Afghan farmers.
Reuters