The NFL is arguably less prepared than they were, to deal with something like this right now, since some of their players seem bent on making themselves an issue/enemy of the police.
Stories out of Miami right now are that both on and off duty police who normally attended games to assist with security are no longer interested in the assignments. Could be likely in other places as well.
The only good news is there seems to be less fans in attendance right now as well.
The more vacant seats, the safer they become. The NFL kneelers might be doing everybody a favor.