Latest: Dallas chief calls shooting of police 'well-planned'

In this still image from video provided by NBC DFW, police officers salute their fallen peers outside Parkland Memorial Hospital in Dallas, where several officers were transported after shootings at a protest late Thursday, July 7, 2016. Five Dallas police officers were fatally shot and seven others wounded during a protest over the deaths of black men killed by police this week in Louisiana and Minnesota. It was the deadliest day for U.S. law enforcement since the Sept. 11, 2001, terrorist attacks. In this still image from video provided by NBC DFW, police officers salute their fallen peers outside Parkland Memorial Hospital in Dallas, where several officers were transported after shootings at a protest late Thursday, July 7, 2016. Five Dallas police officers were fatally shot and seven others wounded during a protest over the deaths of black men killed by police this week in Louisiana and Minnesota. It was the deadliest day for U.S. law enforcement since the Sept. 11, 2001, terrorist attacks. John Fife hands a police officer guarding Jack Evans Police Headquarters a rose in Dallas on Friday July 8, 2016. Snipers opened fire on police officers in the heart of Dallas during protests over two recent fatal police shootings of black men. Investigators leave the home of Micah Xavier Johnson in the Dallas suburb of Mesquite, Texas, Friday, July 8, 2016. A Texas law enforcement official identified Johnson, 25, as the sniper who opened fire on police officers in the heart of Dallas during protests over two recent fatal police shootings of black men. Dallas police respond after shots were fired during a protest over recent fatal shootings by police in Louisiana and Minnesota, Thursday, July 7, 2016, in Dallas. Snipers opened fire on police officers during protests; several officers were killed, police said.