How about a simple RFID sensor solution that can be used detect arms being carried into public places like malls, Schools, religious places, conventions etc. w

How about a simple RFID sensor solution that can be used detect arms being carried into public places like malls, Schools, religious places, conventions etc. were we have most of the public mass killing being reported/targeted. This would be just like RFID sensors used on merchandise's from being shoplifted. only that conceptually the sensor has to work in reverse from preventing objected materials being carried into the premises.