All of the recent shooting related tragedies have one thing in common: They occur in places where the shooter is aware that the people present are disarmed.
The psychology of mass murder tells us that "active shooters" will commonly commit suicide on the spot at the first sign of armed resistance. Be it from a Police Officer responding to the 911 call, or someone in the crowd who is carrying a concealed weapon, the news this year is replete with examples of mass murderers ending their own life because someone pointed a gun back at them.
This reinforces the adage that "The only thing that will consistently stop a bad guy with a gun is a good guy with a gun".
PLEASE! Allow those who have their state-issued concealed weapons permits (teachers & others) to carry while on campus.