There are many more areas conducive to mass murder than there are areas where guns are specifically disallowed. As I mentioned already, the Aurora, CO theater

There are many more areas conducive to mass murder than there are areas where guns are specifically disallowed. As I mentioned already, the Aurora, CO theater was likely targeted specifically because it was the one theater in the area in which guns were specifically banned. Schools might have ostensibly been labeled as 'gun free zones' as an attempt to stymie attempts at committing mass murder within them, but even if we can't prove their effectiveness, we can't deny that their lack of armed defenders makes them an attractive target for someone trying to inflict the most damage. Edit: And for clarity, I wasn't suggesting that the signage causes mass murders to happen - but it does somewhat accentuate that if I were looking for somewhere to wreak havoc, I'd have little opposition in areas with 'gun free zone' signage.