I cringed when I read the opening thread, not the perspective, but what lead up to that.
I'm going to (possibly) step over the line here, but I'd go have a chat with the local Police and relay this story. What this guy will do in public, he's probably doing behind his front door.
Police get a 'Domestic Disturbance' report at least they know (hopefully!) know what to expect? Did this once, years ago when I moved to California and living in an apartment. Sounds from 'next door' really alarmed me being a Fuzzy Bunny Canadian.
Called the Police and had two officers at my door in minutes. Related, they knocked on the door and took him away in 'cuffs.' He'd beat the hell out of his wife.
Just think about my thoughts?