ie, I would expect to hear that this connection is him financially supporting them rather than the other way round
On the other hand, the best argument for the murderer's manifesto being publically available is that at least that way the press can't lie about what's in it.
Most mass murderers are suicidal people who feel powerless and want to die feeling powerful; if that power fantasy is threatened, they change course or suicide.
A lot of mass shooters and mad bombers are experience guys.
NZ PERP, reaching emotional peak. *makes decision to commit terrorism, plans for two years, prepares manifesto, ensures its wide distribution, commits horrifying massacre which he livestreams*
Christopher Dorner's manifesto was like this, for example.
For a lot of perps, like Dorner and Rodger, the audience is "anybody" and the intended effect is "to vent" or maybe "to get people to feel sorry for me"
the first half of his manifesto is just blog posts he hopes will be onramps for normies
His manifesto is not for a broad audience but a very narrow one. He is laser-focused on people who are like him -- serious political extremists who have their shit together -- but *who are not down with the idea of murdering people yet.*
The NZ perp's manifesto is what he told himself. Not how to go from 0 to 60, but to hit the gas at 55.
"Watch out for garbage people" is always a phrase to live by.