Concealed weapons around Children to Protect them?

Actually, there is a new technology(usually keyed to the gun owner's fingerprints or Dna) that would allow hand guns with this technology, where if children found the loaded gun, they could not fire it. So, maybe if teachers in public schools who volunteered to be trained using this kind of hand gun and maybe stored it loaded in their school desk drawer out of sight of the children, then maybe no one else would have to be hired to protect children other than Principals of Schools, teachers, janitors, and school nurses and psychologists.

This would be a natural deterrent to mentally ill young men (or men of any age) who might bring an assualt rifle (or other weapons) to a school to literally (Shoot fish in a barrel) in regard to children or young adults. Because even if teachers and other personnel didn't have assault rifles to return fire with, a 9mm Glock pistol, for example, in the hands of teachers trained to use one would stop anyone not wearing a flak vest. And often a head, arm or leg shot will bring any assailant down.