A police officer who grinned and swayed from side to side as he faced off against protesters is being investigated after footage of him went viral.
San Jose Police Officer Jared Yuen was filmed during a protest last week and was criticised for appearing to be "enjoying shooting people with rubber bullets".
"Even licks his lips. disgusting," the post says.
Yuen has now been placed on leave and is being investigated, police have confirmed.
"I'm not happy with his actions. I'm sure if Jared was sitting here, he would be embarrassed as well," Chief Garcia told reporters.
"I know Jared, and he is a good kid who made a mistake, who let his emotions get the better of him.
"He's put his life on the line for this Police Department on many an occasion. And so we will take all of that into consideration. He will have to live with the consequences of what he did."
Protests against police brutality have continued for an eighth consecutive night, with thousands defying curfew and refused to go home amid reports of looting.
However, protests appear to have been less violent than the night before when looters killed an African American retired police captain in St Louis, one of five police shot during a chaotic evening.