Capt. Rogelio "Roger" Maynulet, 30, is being tried on a charge of assault with intent to commit murder in the May 21, 2004, killing near Kufa, south of Baghdad. He has pleaded not guilty to the charge, which carries a maximum sentence of 20 years in prison.
Taking the stand for the first time Wednesday, Maynulet described his company's mission and the events that led him to fire twice upon the Iraqi, maintaining that the man was too badly injured to survive.
"He was in a state that I didn't think was dignified — I had to put him out of his misery," Maynulet said. He argued that the killing "was the right thing to do, it was the honorable thing to do."
Prosecutors at the court-martial say Maynulet violated military rules of engagement by shooting an Iraqi who was wounded and unarmed.
Maynulet's 1st Armored Division tank company had been on patrol near Kufa when it was alerted to a car thought to be carrying a driver for radical cleric Muqtada al-Sadr and another militiaman loyal to the Shiite cleric.
They chased the vehicle and fired at it, wounding both the passenger, who fled and was later apprehended, and the driver. The killing was filmed by a U.S. drone surveillance aircraft.
Prosecutors grilled Maynulet on why he didn't treat the Iraqi, pointing out that he had been trained in first aid.
Maynulet said the company's medic, Sgt. Thomas Cassady, had told him: "He's gone, there's nothing we can do." He said he wouldn't question the expertise of his medic.
An Army neurosurgeon, Richard Gullock, testified that it was unclear from the surveillance footage whether the driver was alive or dead at the time of the shooting. In the video, the man appeared to be waving his right arm before the first shot.
"I am aware there can be similar movements in someone who can be considered clinically brain dead," Gullock said.
However, a second neurosurgeon, Lt Col. Rocco Armonda of the Walter Reed Medical Center in Washington, countered that the pattern of the man's movements in the video "indicate he was alive."
Maynulet appeared relaxed and spoke confidently as he testified, recounting the events in great detail.