DALLAS, TX - JULY 08: Dallas Police Chief David Brown pauses at a prayer vigil following the deaths of five police officers last night during a Black Live Matter march on July 8, 2016 in Dallas, Texas. Five police officers were killed and seven others were injured in a coordinated ambush at a anti-police brutality demonstration in Dallas. Investigators are saying the suspect is 25-year-old Micah Xavier Johnson of Mesquite, Texas. This is the deadliest incident for U.S. law enforcement since September 11. (Photo by Spencer Platt/Getty Images)
