Defense lawyers blamed mental illness for Sergeant Hasan Akbar's actions on March 22, 2003 in which he allegedly rolled grenades into three tents at Camp Pennsylvania in the northern Kuwait desert as soldiers slept.
In its opening arguments, the prosecution said it would prove that Akbar knowingly and wilfully planned and carried out the attacks.
Akbar faces a possible death sentence if convicted.
A convert to Islam, Akbar faces two charges of premeditated murder and three counts of attempted premeditated murder for the deaths of two US officers and the wounding of 14 other soldiers from his unit, the 101st Airborne Division.
The two officers were Captain Christopher Seifert, 27, and Air Force Major Gregory Stone, 40.
The attack was carried out the night before the unit was to cross the Kuwaiti border into Iraq.
Fifteen witnesses testified to their recollection of the attacks during the first day of the general court martial at Fort Bragg, North Carolina.
A 15-member military jury -- thirteen men and two women -- was selected Friday to hear the case. The jury consists of nine officers and six non-commissioned officers.