'He watched his family get gunned down'

The Associated Press has published the most comprehensive survey to date of mass graves in Syria and Iraq, containing victims of ISIS atrocities.

The survey identified 72 sites containing between 5,200 to more than 15,000 bodies.

Lori Hinnant is the AP International Security Correspondent and visited Iraq to interview eyewitnesses.

(Photo: Man prays for his relative at the site of a mass grave near Camp Speicher in Iraq
Credit: AP)