[jyl]

This particular sort of criminal is difficult to deter, because he expects and intends to die anyway. They're not "rational" criminals.

You can have an armed guard(s) at the school. You can control access to the school property. You can authorize teachers to go armed. You can set up a more rapid police response. You can install cameras so the responding police can locate the criminal/hostages. Etc etc.

Ends up being a cost-benefit sort of decision. "Cost" isn't just financial, it includes turning schools into something like a minimum security prison.

My personal view is, it seems like we're having a surge of school killings right now, it could be a genuine increase in this sort of crime or simply a random blip - kind of like how we can go years without an airliner crash and then have 3 in a year. I'd wait and watch, if it looks like a genuine increase then the cost-benefit decision probably changes and we start seeing armed guards in more schools.