Tell me exaclty how one in uniform stops a black looter, firebomber, perp, etc. from doing anything if they choose to resist and not end up being charged/fired/reprimanded for excessive force, etc.?
Real simple. The same way policing has always worked. You see a crime, you make an arrest. That is your job.
What the da, judge, defense lawyer, jury, appeals court, scotus, etc does days, weeks years later is not relevant when a crime is committed in your presence.