We all know the mantra. Trouble is little if any of it is true. He was arrested for flight and resisting. There were others in the wagon who did not suffer any discomfort. In fact they said he was deliberately trying to harm himself. This was a known drug dealer running from the police. No one witnessed police brutality.
He was not charged with anything prior to booking at the precinct, which never occurred.
In short nothing you repeated is verifiably true. All of the reasons for the riots are made up frauds. Once you get that much straightened out in your head you will begin to be able to understand what is happening.
The police have been charged by the prosecutor. With all due respect, please get your head around that.