Police made more than 150 arrests as a crowd broke windows and knocked down fences, protesting a Los Angeles court decision to sentence a white former transit officer to the minimum term for fatally shooting an unarmed black man.

Friday night’s unrest was the latest in the case against defendant Johannes Mehserle, which has provoked periodic racial strife in Oakland since he shot and killed Oscar Grant while trying to arrest him on an Oakland train platform nearly two years ago.

The protests erupted hours after Los Angeles Superior Court Judge Robert Perry sentenced Mehserle to a two-year prison sentence, provoking immediate anger from the victim’s family and friends who demanded a much harsher punishment.

Oh my!” Grant’s mother Wanda Johnson shouted. She burst out of the courtroom saying, “He got nothing! He got nothing!”

Grant’s uncle, Bobby Cephus Johnson, said outside court: “I do believe it’s a racist criminal justice system.” But he added that the family was reacting calmly.

An Oakland rally billed as a tribute to Grant turned into a march through the downtown area with residences nearby, where demonstrators broke car and bus windows late Friday night. Some carried a banner reading “Justice for Oscar Grant.” Police helicopters hovered above, shining spotlights on the crowd.

Oakland Police Chief Anthony Batts said the protest was declared an illegal assembly after one officer had his gun taken from him in a fight and another officer was hit by a car and suffered non-life-threatening injuries.