One of the most depressing things is that in many US schools it's now routine to have training in what to do in the case of a school shooting incident.
Such things include throwing books / anything at hand at the murderer - things that gain a few seconds, the aim being to reduce the killing rate until "help" arrives.
If the murderers were not armed with guns that make mass slaughter very easy then the death rate would be far lower.
Amidst all the arguments about guns are for sport not killing people. What form of "sport" needs anything like a semi automatic rifle? Any sporting test of marksmanship shoud all be about only needing 1 shot to hit each target - not about spraying multiple shots in a brief period of time so almost impossible to miss.