Ken Klippenstein is a very reliable journalist and this version of the manifesto contains the snippets that have been released by law enforcement. Also, considering the thing was hand-written, that very long version involving his mom is dubious. (And there’s not any good evidence that his mom is in anything besides decent/good health)
"peaceful protest is outright ignored, economic protest isn't possible in the current system, so how long until we recognize that violence against those who lead us to such destruction is justified as self-defense."