Can you video his abusive behaviour, take to police and gain an AVO against offender?
If others are receiving abuse, they can do the same, then you have a number of AVOs against the same offender.
Surely that must carry muster at some stage. Also, if not alcohol based, could be, if aging, a form of dementia or alzheimers?
We had one in our complex, very intimidating & abusive. He passed away eventually.