If you want to really blow their minds, point out that "BLM riots" have ***nothing to do with BLM*** (which is a specific non-violent advocacy organization with its roots in 2013-14). These riots are instead part of a deeper tradition of spontaneous black uprisings that aren't coordinated whatsoever and pretty much always happen, and have always happened, whenever an egregious police abuse incident or lynching happens.
--Bring it back to the Rodney King riots in the '90s.
--Bring it back to the riots that followed MLK's assassination in the '60s.
--Heck, you can bring it all the way back to the slave rebellions and revolts that occurred off and on from the 1600s all the way until that barbaric practice was ended.
The violent abuse of black people in this country sometimes results in a violent backlash. Always has, always will.
Don't like it? Fix it. Don't want to fix it? Then live with it, and don't be surprised when it does happen.
A coup attempt though? That's brand new.