1/13A Dallas police vehicle follows behind an ambulance carrying a patient to the emergency department at Baylor University Medical Center, as police and others stand near the emergency entrance early Friday, July 8, 2016.
3/13A Dallas police officer covers his face as he stands with others outside the emergency room at Baylor University Medical Center, July 8, 2016, in Dallas.
4/13A Dallas police officer, who did not want to be identified, takes a moment as she guards an intersection in the early morning after a shooting in downtown Dallas on July 8, 2016.
7/13Dallas police detain a driver after several police officers were shot in downtown Dallas on July 7, 2016. Snipers apparently shot police officers during protests and some of the officers are dead, the city's police chief said in a statement.
8/13Law enforcement sweeps the area for explosives after a shooting in downtown Dallas on July 8, 2016. Snipers opened fire on police officers in the heart of Dallas on Thursday night, killing some of the officers.
9/13Dallas Police Chief David Brown leaves the Baylor University Medical Center after a visit on July 8, 2016, in Dallas. Snipers opened fire on police officers in the heart of Dallas on Thursday night, killing some of the officers.
11/13A man lays on the ground after yelling "Don't shoot me" at police during a rally in Dallas, Texas, on Thursday, July 7, 2016 to protest the deaths of Alton Sterling and Philando Castile.
12/13A man holds a bat reading "Black Power" during a protest in Dallas, Texas, on July 7, 2016 to protest the deaths of Alton Sterling and Philando Castile.
