I mean in general- this sounds more like an angry liberal shooter than an jihadist. Though if you combine the two... I’m surprised with all the agitation that something like this hasn’t occurred sooner.
Could be some nut pushed into believing the Russians are coming because of all this post election bull crap.
Or could be some greenie upset over the Dakota Access pipeline.
Or someone offended by a Trump tweet.
Or a message to the Cap Hill police about a missing laptop in their evidence room.
Remember all the weirdos that have gotten onto the White House grounds?
I can tell you this for certain: Everybody present took security for granted. Dammit.