If not, why blame shootings on the gun.
The presence or lack of gun raises different behavioral-economic prospects. Sandy Hook is actually archetypal, in this sense: People are free to own guns, and it doesn't matter whether their reasons make any logical sense to me, and that's the way it goes in this society. Meanwhile, the behavioral-economic framework of many gun owners is in its way no more egocentric or solipsistic than many our Republic has engendered, and thus struggles with the difference between what is unimaginable and what they would not imagine of their own. As such, Sandy Hook: It should not have been unimaginable that a psychologically distressed individual might someday commit an act of mass murder in an elementary school; whether one might imagine that prospect of their own progeny is another question, entirely.
Here's how long ago 2007↗ was: It was not unimaginable that a drunk with a history of domestic violence might murder his pregnant ex-girlfriend, but apparently there was this one guy who couldn't possibly imagine that his friend, a dovi repeat offender obsessed with a woman, might one day so easily walk into his place and steal so easily accessible a firearm in order to go kill Rebecca Griego seventeen hours after being arrested for attacking her.
I mean, it's one thing if we've long talked about accidental shootings and homicides by toddlers and secure your guns and all that, but no, a friend steals your gun and you don't notice until the woman he's after is dead, and, yeah, this apparently made a certain amount of sense, at the time, though it's probably unimaginable, today.
But without the easy availability of the firearm, things might well have gone differently. And that, at least, ought not be so unimaginable.