A former soldier who raped an Iraqi teenager and killed her and her family has been found dead in his Arizona prison cell in an apparent suicide.

In the 2006 attack near Baghdad, Steven Green killed the 14-year-old girl's parents and 6-year-old sister before becoming the third soldier to rape her, the Louisville Courier-Journal reports. He then shot her in the face.

The other soldiers are serving time in the Fort Leavenworth military prison but Green was tried and convicted in the civilian justice system.

In interviews with the AP, Green expressed bitterness that he was tried as a civilian under the Military Extraterritorial Jurisdiction Act, instead of in the military justice system, where he would have had a chance of parole.

"I was made to pay for all the war crimes. I'm the only one here in federal prison," he said last fall. "I think they plan to throw away the key in my situation." He said his crimes were fueled by violent experiences in Iraq's "Triangle of Death", and described joining the army as "the worst decision I ever made."