I worked with a "sovereign citizen" in Macon years ago. Super weird dude. I believe he was tied to that "temple" in Macon that got busted for messing with kids.
Not trying to sound snarky or even make light of this horrific tragedy, but the rifle that was picked up at the scene was a flat top without iron sights. Maybe that is what they were driving at?
I personally think he wildly sprayed bullets around.
I think the young man should get a color guard...
The Al Queada and ISIS magazine "Inspire" has advocated using vehicles to inflict carnage and terror for years now. They even mentioned the fact of using vehicles where guns were restricted. They are evil and will do whatever it takes to instill fear and kill.