Riots are seldom spontaneous.
Riots are almost always planned, organized, fomented, controlled, and directed by professional agitators. Where there are riot training sessions, there are professional agitators ... usually NOT from the area of the rioting, and with an agenda that does not benefit any of the supposedly aggrieved people.
The issue is not the issue. The issue is the revolution.
There are plenty of indications that is how Kent State went down.