Other things to look at:
Why can't schools be secured? It kind of mirrors the border and bathrooms issue - just why can't we stop people who shouldn't be some place from being in that place?
There are a disproportionate number of attacks in public schools than private schools. Why is that? Is it because of the generally poor standards at government run institutions? Prevalence of bullying, poor attainment, poor discipline?
Jewish schools have security, because they are under higher threat, and they have fewer mass shooting attacks as a result. It can be done.
Don't tell me they don't have money as they can print and piss it away on anything else they want, especially wars.