of offenses, this history of out loud, incessant, and active hatred, he should have been stopped. Certainly, he should not have been allowed to continue teaching. But that, though it only makes sense, would not have prevented these killings.
If the college women had gone forward, but again, he’d have received at most, more counseling—for sex addiction, anger management—maybe a bit of time or probation, some minimal monitoring.
So make hate talk a crime. Anti-Semitic speech is a crime in some European countries. No. Same deal. He’d have been ordered to sensitivity training. Fined.
The fact that there are thousands malcontent misogynists feeding each other online does not help
from a law enforcement standpoint. Which one will go on to a rampage? Between his writings and his behavior, pretty clear he had psychopathic tendencies, but unless we live in a minority report
society...
Given his run-ins, types of offenses, had he been charged, ordered to psychiatric evaluation, maybe in a state that had strong gun regulation...problem is he did not have a mental illness. And if he had a mood disorder concomitant to his social sickness, that would probably not have barred him even under stricter gun laws from possessing a gun. One would think a gestalt—sex offenses, a trail of violent writings, a psychological profile, participation in hate groups—all this could add up to some consequence that would have deterred him.
Other thoughts?

He bragged about being a Libertarian. Not to mention all women were genetically inferior in his eyes. All they wanted to do is marry up and improve their social status and bleed men of money.

This guy constantly bragged on himself as he thought he was the greatest thing in the world, and thought women should just flock to him.

The guy would never work. All he would do is stand around and run his mouth and get in the way and blame people for how bad is life was.

And, naturally, he liked guns. Large high caliber high capacity long-distance reach out and tag someone type of guns.

Well, maybe because they could tell how much you hated and feared them? There are plenty of average-looking men who don't lack for female companionship. That's because they actually LIKE women. Women have choices. Women don't have to settle for men who despise them.

is now more and more people actively cheerlead for mass shooters and call them "heroes"