The investigation, being conducted by the Iraqi government, was launched after officials were confronted with numerous allegations of “war crimes,” based in part on dozens of ghastly videos and still photos that appear to show uniformed soldiers from some of Iraq's most elite units and militia members massacring civilians, torturing and executing prisoners, and displaying severed heads.
The videos and photos are part of a trove of disturbing images that ABC News discovered has been circulating within the dark corners of Iraqi social media since last summer. In some U.S. military and Iraqi circles, the Iraqi units and militias under scrutiny are referred to as the "dirty brigades."
“As the ISF [Iraqi Security Forces] and militias reclaim territory, their behavior must be above reproach or they risk being painted with the same brush as ISIL [ISIS] fighters,” said a statement to ABC News from the U.S. government. “If these allegations are confirmed, those found responsible must be held accountable."