Torture, beheadings, the cold blooded shooting of unarmed civilians, and all of it caught on camera in war-ravaged Iraq by the perpetrators acting with impunity. But the horror show was not by ISIS this time. An ABC News investigation, "Dirty Brigades: No Clean Hands in Iraq's ISIS Fight," found ample evidence of terrorist-like atrocities routinely committed over the past year by U.S.-trained Iraqi Security Forces, who Washington has been arming as the key to defeating ISIS. Incredibly, elite Iraqi Special Forces, special police and counterterrorism units were documenting their own horrific acts, filling the dark underbelly of Iraqi social media with gruesome snapshots and videos of their own war crimes in an apparent effort to stir up sectarian bloodlust. In the first in-depth exposé and analysis of these atrocities, the ABC News Brian Ross Investigative Unit, led by Producer James Gordon Meek, spent six months collecting and researching a photo and video gallery of horrors, interviewing human rights investigators, U.S. Special Forces veterans and diplomats who served in Iraq, as well as confronting both the American and Iraqi governments with their findings. The team presented the investigation to millions over three consecutive nights on ABC World News Tonight With David Muir, accompanied by in-depth digital reports, both print and broadcast, on ABCNews.com and ABC/Apple TV.