I disagree. Forward a copy to the authorities and delete that crap. We don't need to leave it up for a bunch of amateurs to play the "which tribe can I blame for this" game and provide noteriety, name recognition, and a platform for the shooter's dumb message.
We don't need to make them famous, and have their manifesto or whatever crap they posted online to stay visible.
Too bad the media still publish their names and pictures like they did with the pipe bomb dude.
I rather hear about the victims, the police officers shots/killed, the first responders and all the good folks.