Yeah, if there had been an armed teacher or two at Sandy Hook, there would be no news about a would-be shooter taken out prematurely.
The problem with this solution to school shootings is that both modern "teachers" and spree shooters are universally Leftist and functionally borderline mentally retarded.
Ponder this: Over the last forty years, since the Bolsheviks have pushed the concept that every pupil "needs" college, it has been the habit of academia to shovel the bottom of the barrel students into eduction and journalism.
These are now the sources of the daily news items of Zero Tolerance stupidity, and you want to promote morons with guns?