Yes it would be a discussion to have because a next time could be a nutty school bus driver or other employee, maybe even a parent.
Every nutty person can get a weapon.
The issue is whether having the gun present within the school property would increase the chance of the nutty person showing up at work with a weapon.
Since it would be likely that those teachers trained to carry weapons would be teachers who owned weapons already, those teachers, should they become “nutty”, would have already had access to weapons, so the only difference is whether they have to smuggle their weapon into school, or whether they could openly have their weapon in the school. Given that it is trivial for a teacher to carry anything they want into a school, I argue there is no increased risk if they have the weapons already. This assumes training included how to properly store the weapon in a safe and secure manner.
There is of course the increased risk that the gun will be improperly stored, and therefore accessible by someone who immediately goes crazy while at school, but who would otherwise not have access to a gun. That risk seems extremely low. It might not be lower than the risk of a shooting — but the risk of a shooting is extremely low, and by that standard we should do NOTHING.
Our problem is that, regardless of the extremely low risk of your child being shot at school, the masses feel compelled to act to do SOMETHING to mitigate the risk. None of the gun control suggestions would do anything to lower the risk, certainly not in any measurable way.
BTW, part of the reason for that is you can’t really MEASURE the risk, because it is so low that it is in the noise. I can give you a percentage each year of mass murders in schools, but if you plot it yearly, the graph is random; it’s not a statistical event, it is an extraordinary event. You could ban every gun, confiscate all but 1000 of them, and you’d still have more guns not confiscated than there have been guns used in mass murders.
And of course, nobody is proposing a law to confiscate all weapons; nor would such a law be useful. If you banned the manufacture and sale of every gun, it would be decades before it made an appreciable dent in the number of weapons, since they last forever.
Banning bullets would be more effective, but there are still more than enough bullets manufactured to kill every person in our country multiple times over. And since the police would still need bullets, there would be an easy supply for criminals.
I don’t think we should allow every school employee to bring guns. I would envision a special program, like what the airline pilots had, to train and test people for the job.
But if we had such a program, I would feel confident in saying that the chances of one of our armed teachers going nutty is less than the chance of one of our armed police officers going nutty.
(I speak of schools like all the ones where mass killings have taken place — I understand a small number of schools have metal detectors and such).