"Gun Free" zones are not logical gun control measures. It only criminalizes otherwise lawful behavior. A college student crossing campus at night should be allowed to defend themselves if attacked. A Parent walking their child to school should not risk arrest (and thereby the loss of the right to carry) simply because they are carrying a lawfully possessed & permitted weapon with them at the time. How many mass shootings would it stop? Probably none considering how few mass school shootings have actually occurred. How many would be interuppted, unknown because we really don't know how we'll react in such a situation. But in those instances where someone was armed, and had the opportunity to interecede, it has certainly limited the the potential carnage.