The US Army is investigating possible war crimes after a soldier facing murder charges in the killings of two Iraq war veterans told investigators he and another soldier randomly fired at Iraqi civilians while driving around Baghdad. Pfc. Bruce Bastien Jr. and two former soldiers face charges in the December shooting death of Spc. Kevin Shields, while Bastien and one of the former soldiers face charges in the August 4 shooting death of Pfc. Robert James. Fort Carson spokeswoman Dee McNutt confirmed the Army investigation into the Iraq shootings detailed in a motion filed by prosecutors Tuesday seeking to combine the two killings into one case. Bastien said he and another soldier used stolen AK-47 military rifles to shoot at civilians while their unit patrolled Baghdad neighborhoods, and at least one civilian was hit. "The sound of an AK-47 is very distinctive," the motion quotes Bastien as telling Kelly Jameson, an Army criminal investigator, on Dec. 10. "So if there were any questions when the shooting was heard, Bastien said they could claim they were taking on hostile fire."