Chuckles.
You're solving a problem that shouldn't exist. It's easy to identify the criminals when they are the only ones holding the guns.
And then there's this $8 solution to beat your system anyway
http://www.instructables.com/id/DIY-Wifi-Jammer-With-ESP8266-and-Mobile-App/
May need to be a wired connection then.
The police can also tell who the bad guys are if they're the only ones left alive when the police finally enter.
It's certainly a problem which shouldn't exist, but it does exist; and there's a debate raging between those who believe the solution is fewer guns, and those who believe the solution is fewer gun-free zones.
Unless and until they fix mental health, guns, prayer in schools or whichever other culture-wide issue needs to be addressed; I think this is a reasonable stop-gap which delivers the benefits of a gun free zone, and the benefits of armed deterrence.