Shocking video has emerged which depicts police officers firing rubber bullets into a rioting crowd which includes women and children.
As officers were investigating what happened at the scene in Anaheim, California on Saturday, an angry group of people began yelling and throwing bottles at them, according to Sergeant Bob Dunn.
After police detained several people, the crowd apparently advanced on the officers, who responded by firing tear gas and beanbag rounds at them.
Video captured by a bystander and broadcast by KCAL-TV showed a chaotic scene in which officers fired beanbag rounds as some people ducked to the ground and others scattered screaming.
Mr Dunn said the dog was 'deployed accidentally' after somehow escaping from a patrol car.
The shooting that kicked off the violence involved Manuel Diaz, 24, who was shot in front of an apartment complex around 4pm on Saturday following a foot chase and died in hospital three hours later.