This shooting is yet another tragic example of the failed, grotesque insistence on helpless victim zones where any crazed gunman can be assured of a large number of disarmed, undefended, helpless victims, all crammed into one place, where he can kill many children before an armed defender arrives from elsewhere. It is disturbing and sick that the federal government so hates the right of the American people to bear arms, and so hates their natural right to self defense, that the government insists on making them helpless, disarmed victims for anyone who cares to kill them. And in this case, all of the teachers and staff were willfully disarmed by the Federal Government, by force of law and threat of prison, to ensure that they would be disarmed and incapable of saving the lives of the children entrusted to their care.
That makes the Federal Government complicit in the deaths of these children, and in fact an accessory to their mass murder, by forcibly disarming (with the very real threat of prison) all the teachers, all the staff, and any parent who may have been on school property. That stupid law guaranteed the shooters would meet no immediate armed resistance, which is exactly what is needed to stop such an attack.
In such a shooting (as in every criminal attack), seconds count, and the people best positioned to stop the attack are the people on the scene - the intended victims and/or their care-takers. In this case, that would mean the teachers and staff of the school, and also the parents, who should have the ability to save the lives of their own children as they take them to and from school.