The article doesn't do a very good job explaining what the guy got hauled in for but a bunch of these weapons could be full auto, which would go a long way toward an explanation.
The comments had several comments from people familiar with the story and a few mentioned that the guy was a felon and several others claimed the police found the guns while responding to a drug complaint.
Poor reporting was also obviously involved.
Yes, could be full auto. But those are quite hard to come by, being worth some 20x their semi-auto equivalents (which look identical).
Occam’s Razor: all of those are _easy_ to obtain in semi-auto form, and easy to transgress NY/NYC laws with - so that’s the far more likely case.
Heck, that looks a whole lot like (and numbers less than 5x bigger than) many of our collections - few of which include multiple full-auto guns.