“In June 2008, a man wearing sunglasses and a baseball cap entered a 7-Eleven store in Killeen, Texas, pointed a gun at the clerk, and demanded money. A string of similar robberies had taken place at stores in the area, which is near Fort Hood, and police suspected they were all the work of one man. This time, they got lucky: a surveillance camera captured the robber as he fled the scene. They put the video on the evening news, and a phone tip led them to George Powell III.”