From ArmedwithReason.org

This post challenges the belief that ‘gun-free zones’, areas such as schools and work place institutions, are breeding grounds for a mass shooting. The commonly held belief that mass shooters are attracted to gun-free, vulnerable areas is shown to lack evidentiary substantiation. The idea that schools have been made safer by armed guards is also challenged

http://www.armedwithreason.com/the-gun-free-zone-myth-no-relationship-between-gun-free-zones-and-mass-shootings/