FILE - - In this March 13, 2009 file photo, Iraqi Army soldiers look at a book of Arabic phrases as U.S. Army Staff Sgt. Robert Williams, 37, assigned to Delta Co. , 1st Combined Arms Battalion, 67th Armor Regiment, looks for help in communicating in Mosul, 360 kilometers (225 miles) northwest of Baghdad, Iraq. The Feb. 24, 2009 shooting, which killed a U.S. solider and an interpreter and wounded five others, was an alarming inside job that reinforced what many fear: insurgents and sympathizers possibly infiltrating the ranks of Iraq's security forces. AP Photo logo AP Photo 6 months ago

FILE - - In this March 13, 2009 file photo, Iraqi Army soldiers look at a book of Arabic phrases as U.S. Army Staff Sgt. Robert Williams, 37, assigned to Delta Co. , 1st Combined Arms Battalion, 67th Armor Regiment, looks for help in communicating in Mosul, 360 kilometers (225 miles) northwest of Baghdad, Iraq. The Feb. 24, 2009 shooting, which killed a U.S. solider and an interpreter and wounded five others, was an alarming inside job that reinforced what many fear: insurgents and sympathizers possibly infiltrating the ranks of Iraq's security forces.