Joint Base Lewis-Mcchord, Washington (CNN) - "The plan was to kill people."
That's what Army Spc. Jeremy Morlock said Wednesday during a court-martial proceeding against him, moments after pleading guilty to killing Afghan civilians in 2010.
Lt. Col. Kwasi Hawks, the military judge in the case, had asked Morlock if he and fellow soldiers just meant to scare civilians with grenades and gunfire and it "got out of hand."
Morlock and four other soldiers face murder charges, accused of killing Afghan citizens for sport. Seven more soldiers are accused of helping cover up the killings.
Morlock also pleaded guilty to charges alleging that he used drugs, as the court-martial opened at Joint Base Lewis-McChord in Washington. He has pleaded not guilty to charges that he hit another soldier and that he photographed and possessed photos of dead Afghans.
Morlock was charged with three counts of murder. He was accused of killing one Afghan civilian in January 2010 with a grenade and rifle; killing another in May 2010 in a similar manner; and shooting a third to death in February 2010.
Another soldier, Pfc. Andrew Holmes, also faces charges in the case, but a start date for his court-martial has not been publicly announced.
In all, officials charged 12 U.S. soldiers in what they called a conspiracy to kill Afghan civilians and cover it up, along with charges they mutilated corpses and kept grisly souvenirs.
Morlock was the first of the five to face an Article 32 hearing, the military equivalent of a grand jury hearing, at Joint Base Lewis-McChord.
Holmes is charged with the premeditated deaths of three civilians, possessing a dismembered human finger, wrongfully possessing photographs of human casualties, and smoking hashish.
He is also accused of conspiring with Morlock to shoot at a civilian and then toss a grenade so it would appear that the soldiers were under attack.
All of the accused men were members of a 2nd Infantry Division brigade operating near Kandahar in southern Afghanistan in 2009 and 2010.
The three others facing murder charges are Staff Sgt. Calvin Gibbs, of Billings, Montana; Adam Winfield, of Cape Coral, Florida; and Spc. Michael Wagnon, of Las Vegas, Nevada.
Authorities allege Gibbs kept finger bones, leg bones and a tooth from Afghan corpses. Wagnon allegedly kept a skull from a corpse, according to charging documents.
Several soldiers are charged with taking pictures of the corpses, and one soldier is charged with stabbing a corpse.
This week, German news outlet Der Spiegel published photographs which it said showed Morlock and Holmes posing over the bodies of dead Afghans.
Two images show the soldiers kneeling by a bloody body sprawled over a patch of sand and grass. A third shows what appears to be two bodies propped up, back to back, against a post in front of a military vehicle.
The U.S. Army released a statement Monday calling the photographs "repugnant to us as human beings and contrary to the standards and values of the United States Army."
"We apologize for the distress these photos cause," the statement said.
Army officials asserted in the statement that ongoing court-martial proceedings related to the alleged atrocities "speak for themselves."
"The photos appear in stark contrast to the discipline, professionalism and respect that have characterized our soldiers' performance during nearly 10 years of sustained operations."