We are 'in' the news now…
The manifesto was first shared on the toxic trolling board 8chan minutes before the suspect opened fire. It contains apparent misinformation and is clearly meant to be found and disseminated. (It uses the same question-and-answer format of the manifesto of the terrorist who attacked two mosques in Christchurch, New Zealand.)
https://www.thedailybeast.com/san-diego-synagogue-shooting-multiple-people-including-children-injured-at-synagogue-chabad-of-poway-suspect-in-custody?ref=home