Its because they are all patsy's. The FBI find these people on psychotropic drugs who have a history of being crazy found on Facebook, twitter, etc which have CIA members in the company feeding them intel.
Then mysteriously the shooter has guns and ammo given to them by an undercover fbi agent or agents usually the real shooters. They tell them to go to a gun free zone and then FBI always kills them before they get interrogated. Remember vegas shooting. Alot of reports of gunfire from other directions.
Then immediately media swarms in to tell get rid of your guns. "Never get rid of your guns"
Solution: always carry even in gun free zone. If you are afraid of your kids getting shot at school you should homeschool.
Where were all the concealed carriers in Texas? I carry every where, every day out of fear for an event like this.
Simon malls are gun free but it never stopped me.