They have actionable intelligence that things will go south upon "no bill" by GJ.
Do you have any idea if the grand jury decision will announced? Before or after the violence?
I fear you are right. I suspect the August protests will seem like a normal day compared to the potential of a “no bill” by the GJ.
If I lived in the area I would remove any valuables/family heirlooms and put them in storage far away and keep enough clothes and personal items in my car to be ready to leave the minute the decision is announced.