I had no idea fully automatic rifles are legal ANYWHERE. I’ve always heard about it being illegal to convert a rifle to fully automatic.
This guy definitely had the bucks. He owned two airplanes.
This would have been 1985. Then, in 1986, Reagan signed a law that said no private citizen could own a machine gun that had been manufactured after 1986. All full auto increased in price at least ten-fold. The M-60 today is about $60,000.
Thing is, I've only heard of one time a legally acquired full auto was used in a crime. It just doesn't happen. Even though there are thousands of them out there.
I'll be very surprised if this shooter was using full auto.
Google "auto glove" and watch the video. Just one possibility.