It’s ridiculous to look for any justifications for his actions within his manifesto.
His actions were indefensible.
The left will use his arguments to condemn others.
And as far as gun control, from what I heard on radio last night, he was a felon and couldn’t buy a gun. Allegedly his father bought him the gun (knowing he couldn’t) which is also a felony (and wouldn’t be stopped by background checks).
Guy isn’t a felon. From what I understand, he has been charged but not convicted of a felony, and was therefore ineligible to buy a gun legally.