Lori Hinnant, international security correspondent, Paris; Desmond Butler, international investigative reporter, Washington; Maya Alleruzzo, Middle East photo editor; and Francois Duckett, graphics, for documenting the high number of mass graves that the Islamic State group is responsible for, through interviews with witnesses, mass grave officials, NGOs and activists, and satellite photos. http://bit.ly/2clBkkZ http://trib.in/2cojfDv http://bit.ly/2cFTY6H