Now as far as the gun free zones & the relation to violence...From the article that someone posted at mother jones....
"Half of the cases involved school or workplace shootings (12 and 19, respectively); the other 31 cases took place in locations including shopping malls, restaurants, government buildings, and military bases."
Of that list schools, government buildings, & military bases are gun free zones via federal law.
Most work places do not allow their employees to pack even with CCWs.
Many malls & restaurants are self declared gun free zones as well.