Dangerous Darla Darla, a German shepherd assigned to the Army's 549th Military Working Dog Detachment, conducts aggression training at Joint Base Elmendorf-Richardson, Alaska, March 21, 2017. Air Force photo by Justin Connaher SHARE: Download: Full Size (1.3 MB) Credit: Justin Connaher VIRIN: 170321-F-LX370-1540C.JPG Photo Gallery