A U.S. Army tank company commander told a military court Wednesday that he shot a gravely wounded, unarmed Iraqi man "to put him out of his misery," saying the killing was "honorable."

Taking the stand for the first time, Capt. Rogelio "Roger" Maynulet (search), 30, described 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 justified — 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 is being court-martialed 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, and his lawyers have argued that his actions were in line with the Geneva Conventions (search) on the code of war.

Maynulet's 1st Armored Division (search) tank company had been on patrol near Kufa when it was alerted to a car believed 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 did not treat the Iraqi, pointing out that he had been trained for medical emergency relief.

Maynulet said the company's medic, Sgt. Thomas Cassady, told him: "He's gone, there's nothing we can do." He said he would not 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 (search) in Washington, countered that the pattern of the man's movements in the video "indicate he was alive."

Maynulet appeared relaxed and spoke confidently, recounting the events in great detail.

Questions from the six-member panel — the equivalent of a civilian jury — focused on whether Maynulet tried to hide his actions by failing to report the shooting at the end of the day. Maynulet said he discussed the shooting in a debriefing that immediately followed the mission and denied trying to hide the killing.

He further testified that, as company commander, he had more important priorities on the mission than saving the Iraqi, including searching for two escaped passengers and maintaining the safety of his men.

He testified that he was reluctant to expend limited first aid resources on a man he had been told would die anyway.

His command was suspended May 25, but he has remained with his Wiesbaden-based unit.

Iraq's interim deputy defense minister, Ziad Cattan, testified later Wednesday that he worked with Maynulet when the soldier was stationed in Baghdad and had contact with Iraqi officials.

Cattan, a district council chairman at the time, described him as "a good soldier and a good officer." Asked about Maynulet's attitude toward Iraqis, Cattan said: "He is very compassionate."

The U.S. military has referred to the Iraqi driver only as an "unidentified paramilitary member," but relatives named him as Karim Hassan, 36. The family does not dispute that he was working for al-Sadr.