Wanna bet that the cops would decide to intervene on behalf of the rioters, basically working as their security detail?
As for dealing with violent rioters, after MLK was killed and Detroit burned, the usual suspects began looting & burning in Chicago. Then-mayor Richard J. Daley (the papa of a more recent mayor) issued orders to the police department: SHOOT TO KILL arsonists, SHOOT TO MAIM looters.
As soon as the word went out, 99% of the rioting stopped in its tracks.