A U.S. Army soldier accused of killing 16 Afghan villagers appeared in a military courtroom for the first time Monday.
Prosecutors say Staff Sergeant Robert Bales was "lucid," "coherent" and "responsive" when he carried out the attack.
Prosecutor Joseph Morse said Bales spent the night before the raid drinking whiskey and watching a violent movie with fellow soldiers.
He says that sometime around midnight on March 11, Bales left the base and walked to a nearby village and carried out the first set of killings. The prosecutor says Bales then returned to the the base and told a soldier he had "just shot some people" in the village of Alkozai, but the friend thought he was joking and did nothing.
Later, Bales left the base for a second time and headed to another village, where he killed more people.
The hearing at Joint Base Lewis-McChord in the northwestern U.S. state of Washington is expected to last two weeks, with some of the proceedings taking place overnight in order to include live video testimony from witnesses in Afghanistan.
The hearing will determine whether Bales faces a court martial.
Bales, an 11-year military veteran, faces 16 counts of premeditated murder, six of attempted murder, seven of assault, two of using drugs and and one of using alcohol while deployed.
If convicted, he could receive the death penalty. The U.S. military has not executed a service member in five decades.
U.S. forces have paid compensation to the families of the dead and to those wounded in the attack.
Staff Sergeant Bales was on his fourth military deployment, after three in Iraq, where reports say he suffered a brain injury.
Some information for this report was provided by AP and Reuters.