Reading this I wondered ? I assumed it was only about really large weapons.
Routh has a criminal record dating back to at least 2002, when he was convicted in Guilford County, North Carolina, on one felony count of possession of a weapon of mass destruction, according to a review of state court records.
I just saw this post that clarified it was a fully automatic machine gun. Weapon of mass destruction sounds like a nuke, but from a legislative perspective, I can see how a fully automatic machine gun would qualify.