Violence against the police is NOT the answer, either. These were innocent people doing nothing other than their jobs.
CNN is reporting that at least one person who was at the protest is stating that they are alive today because a police officer shoved them out of the way of gunfire. Think about that, while someone is shooting AT police, trying to pick them off and kill them for whatever reason, this officer's instinct was still to get the civilian out of harm's way.
I have family that are first responders. I have friends that are first responders. I have had a grade school classmate killed senselessly in the line of duty as a police officer. All of them are good, decent people that I have no doubt put others before themselves every single day. And I am sure that 99.99% of all other first responders are the same.
Violence against other human beings does not end violence. Enough already.