POTUS can use Army/Navy/AirForce/Marines in the event of insurrection or civil disturbance.
So, if there were actual large riots, POTUS could send military.
It happened in the 1992 Los Angeles riots.
Active duty Army and Marines were deployed to LA.
Military can share and work with civilian authorities.
https://fas.org/sgp/crs/natsec/R42659.pdf