A U.S. Army tank company commander accused of killing a critically injured driver for radical Shiite cleric Muqtada al-Sadr in Iraq will be court-martialed, an Army spokesman said Tuesday.

The American told a fellow officer he killed the Iraqi out of compassion, according to testimony.

Capt. Rogelio Maynulet (search), 29, of Chicago, was ordered court-martialed following an Article 32 hearing, the military's equivalent of a civilian grand jury investigation, division spokesman Maj. Michael Indovina said.

The order to court-martial Maynulet came Monday from 1st Armored Division (search) commander Maj. Gen. Martin Dempsey.

It was not clear when the court-martial would start, but in the meantime,

Maynulet will continue to serve on the division's planning staff, where he was assigned after his command was suspended May 25, Indovina said

He will be tried on charges of assault with intent to commit murder and dereliction of duty under articles in the Uniform Code of Military Justice (search) that leave punishment up to the discretion of that court.

Maynulet had been charged with murder following the May 21 incident near Kufa in Iraq and it was not clear whether the Article 32 hearing officer recommended the lesser charges for court-martial, or if that was Dempsey's decision.

Maynulet's defense attorney, Capt. Will Helixon could not be reached for comment.

The incident occurred when Maynulet was leading his tank company on a patrol. They came across a BMW sedan believed to be carrying a driver for al-Sadr and another militiaman loyal to the cleric, whose supporters rose up against U.S. forces twice this year.

U.S. soldiers chased the vehicle and fired shots at it, wounding both the driver and passenger.

When a medic pulled the driver out of the car it was clear he had suffered critical injuries, with part of his skull blown away, according to testimony during the Article 32 hearing.

Maynulet's fellow officer, 1st Lt. Colin Cremin, testified that Maynulet told him he then shot the Iraqi in the base of the neck or the back of the head.

"It was something he didn't want to do, but it was the compassionate response," Cremin testified. "It was definitely the humane response."

The killing was caught on video by a U.S. drone surveillance aircraft, and the footage was played back during the Article 32 hearings after the public and reporters were removed from the courtroom.

Hearing officer Maj. Michael J. Fadden said the footage was being kept classified because it could reveal the Army's capabilities in Iraq.

No venue has been chosen for the court-martial. The Article 32 hearings were held in Hanau, near Frankfurt.