>Was this man well known on 4 Chan?
The entire point of the site is that nobody here can become well known. Posts are judged by immediate merit rather than posting history. We have these things called trips you put into your name, hidden behind a password, used if you need to confirm your identity for some reason. He did not use one, but the corrupt moderation team no doubt is capable of singling his posts out despite often claiming the opposite.
>Did he make threats of violence prior to the attack? If so; for how long?
No way to know, did not use a trip, the one time he posted his manifesto it was on 2times4chan, a different site than this one.
>What was his motive?
Read his manifesto and decide whether it's convincing on his own, it's been already thrown at you.
>I've heard he wrote a semi-humorous manifesto of sorts, is this true?
See above.
>Where is the original page he announced the attack in, does it still exist?
Yes, the whole thread with the announcement is archived, if you dig through 16/2chan you should find it.
>Does the average user of this website support these actions?
The average user of this website does not give a fuck about the proceedings of this one particular board, Jow Forums. The average user of this BOARD seems to be, let's see, 25% condoning, 25% denouncing, 50% questioning the legitimacy of information we are given (calling it a false flag). There is heavy political advertisement going on from various parties, especially during such events, so figuring out which posts are genuine is difficult, and the ratio may be skewed.
>Did the website's administration make any attempt to ban the person or contact the police?
Point this question to the site where he actually posted, but no.
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