schools will not arm teachers due to the insane legislation and lawsuits that could or would ensue. Teachers are barely able to discipline kids these days, much less actually carry lethal weapons on their persons.
What needs to be studied is the connection between medications for mental illness/disorders, such as zoloft, ambien, etc. that are KNOWN to cause suicidal thoughts in patients (they even have to mention it in the commercials). Most of these mass murderers were previously medicated or off their meds when they did their horror.