Police: 4 officers killed during Dallas protests

11:05 p.m. (all times local)
Dallas police say four officers have died after at least two snipers opened fire during protests downtown. Seven other officers were wounded.
Police Chief David O. Brown said police have a suspect cornered in a garage and are negotiating with that person. He says the snipers fired upon officers “ambush style.”
Brown had said three officers were killed, and police issued a tweet later saying a fourth officer had died.
Brown says snipers shot from &ldq