US federal authorities have agreed to review the case of two Latino men shot dead by police in Anaheim.
The city's Mayor made the announcement after a fourth night of clashes between police and angry residents.
Meanwhile, the mother of an unarmed man who was shot by police officers has condemned violent protests against the killing, saying on Wednesday she did not want them to become her son's legacy.
"I watched as my son took his last breath. I watched as his heart stopped beating for the last time," Genevieve Huizar said, breaking into sobs. "Please, please, please stop the violence. It's not going to bring my son back, and this is the worst thing any mother could go through."
In the latest wave of protest, as many as 600 demonstrators surged through downtown on Tuesday night, smashing shop windows, setting trash fires and hurling rocks and bottles at police, authorities said.
Al Jazeera's Rob Reynolds reports from Anaheim in California.