Equip all teachers with a fast acting tranquilizer

The greatest deterrent to people who commit mass shootings is being caught. These people don't care about dying since it's their intent to kill themselves and the reason they do it is because they don't want to be in prison. People in prison don't take kindly to child killers. If all teachers had access to a tranquilizer they would be able to stop the attach and get the person taken into custody. This is the greatest compromise between the two sides