Demonstrators sprayed several officers with “bear mace” and vandalized shops as they walked from downtown Oakland all the way to Berkeley to protest the shooting death of an unarmed African-American teenager by a police officer in Ferguson, Missouri. One officer assaulted by protesters had to be taken to the hospital.

The police union issued a letter to city leaders on Wednesday criticizing commanders for not being adequately prepared or staffed to handle the march and for letting it continue after several protesters became violent.

“People should have the right to peaceful protest, but once there’s violence, it’s no longer a peaceful protest,” union President Barry Donelan said in a phone interview. “The whole thing was ill-planned and the implementation was terrible. And having police officers get hurt is totally unacceptable.”

Donelan said follow-up protests this week have been handled better.

Chief Sean Whent said in a prepared statement Friday that he reviewed last week’s protest with his command staff and revised several planning protocols.

“Keeping officers and the community safe is my priority, and I am committed to continuous review of our policies, procedures and tactics with the goal of minimizing the dangers involved in these situations,” he said.

Read a letter from the Oakland Police Officers’ Association here.

Watch Video From The March Here: [Video] Oakland to Ferguson Protest FTP