IMO the problem is "self-defense" and "group-defense" and a solution must satisfy both.

[RC]

10. The solution is to work toward where "self-defense" and "group-defense" is not needed.

Work on eliminating the threat, is the best option long term option, instead of diddling with the symptoms and blaming the shooter as if they were the sole cause of whatever mass execution. The root problem is lax gun regulation and too many easily obtained weapons.

A lone perpetrator with baseball bats and/or knives won't get very far in his fantasies of mass killings in theaters or schools. A sniper in the woods next to a school, trying to throw knives to pick off the kids? Sure. Easily obtained guns are the problem.