My first question is how did this guy get a full auto weapon. You have to go through a rigorous background check for a class 111 stamp and the cheapest one is about $14,000.
I knew a guy who had a very impressive collection of WWII German weapons, including a belt-fed MG-34. He used to dress up in a Wehrmacht uniform and go out to the shooting range and film VHS tapes of the weapons in action.
Anyhow, at 64 this guy could've easily amassed the resources required to build a collection of legally-owned automatic weapons. With no police record, as is being reported, it wouldn't have been very difficult if one was motivated.
$14,000. I know guys who spend that on electric guitars.
I frequently see Uzis and macs in the six k range.