[PilloryHillary]

ASSAULT TYPE RIFLE WAS AT THE SCENE.

[Godebert]

Perhaps a Disgruntled employee or ex-employee?

[atomic conspiracy]

"ASSAULT TYPE RIFLE WAS AT THE SCENE."

Could be almost anything with black plastic parts, including a .22 semi-auto.
Actually, the old AR-7 survival rifle would be a good suspect; rest of the gun breaks down to fit in the black plastic stock, making it fairly easy to conceal going in.

[Dan from Michigan]

What the hell is an "assault type rifle"???