Thanks. Seems to me what matters is not the proficiency (above some minimum, most important is not accuracy but knowing when NOT to pull the trigger) but just the publicized fact that the school is NOT a “gun free zone”. Even a school shooter who plans on suicide at the end is not going to want to be eternally humiliated by being cut short be returning fire.
I’m sure that there are studies out there that would prove or disprove that theory.
I think you are right. They would prove the assumption correct.
There are actually VERY FEW crazy folks who are crazy enough to not care about getting shot by someone else, even if they plan on offing themselves at the end.