Homocidal maniacs look just like everyone else.
Did you ever see the film "Intensity" starring John C. McGinley? Chilling. The sniper may be someone as you described.
A lone nutjob has more than one gun.I know we FReepers are anxcious for a quick resolution, but if it is a lone nutcase, or even if it is a "cell member",chances are more than one weapon is a "possesion" by unidentified nutjobber.
Shoot, my highest count, officially, was 15 "guns".Various makes and models.I also had a Tarot deck laying around the house, somewhere.LOL
This is a wide open, equal opportunity nutcase operation.Settle, and steady yourselves.
The time to panic is not yet set.Soon.