Good grief! I have never seen such a collection of invertebrates in one place!
If schools need guards, and uniformed guards are not the best idea, then what is a better idea? How about a citizen or two who has matured beyond the emotional age of seven or so, and is able and willing to carry arms in his/her own defense? Even if some of those citizens are teachers or school administrators!
Heck, I bet at least 5% of teachers would like to become adults some day!