CCTV does not stop crime, but helps in conviction. if Sandy Hook kids had one minute prior notice, atleast half of them would be alive, I am a parent myself with kids in same age group, so every possibility still excite me

Didn't the killer shoot the person who would have monitored the firearms first before taking them? So this solution would only be helpful if law enforcement actively tracked the position of all "assault weapons" at all times. And that seems like a bad idea on a variety of levels.

Simply prying the device off or smashing it with a hammer would also work.