I disagree violence is needed against police but I entirely can see how it's a valid & logical opinion of some people. So if it was just violence against police, & government owned buildings I wouldn't have as much of a problem.
The thing is though a lot of the violence that happens surrounding these events are not exclusively directed at police or government owned buildings. So where as violence against the police is at least on a spectrum of things isn't totally outrageous. Harassing, assaulting & sometimes killing other citizens is not necessary, looting, burning down stores & destroying property isn't necessary. Would you say that protests have been turning into riots? (even if in your opinion it is the police's fault it goes that way)
Can you have violence against police without the lawlessness & mob mentality spreading? You do quite a bit of grandstanding in your post imo.