Sucks to hear all that. It can get better. My best advice would be to consistently call the police on any incident. You are not the bad person by doing this. I'll try to summarise my experience and the roadblocks decisions I made.

The complex has approx 4-5 units. Previously the worst resident was a small pregnant lady with schizophrenia. Whilst she was annoying as all hell, we just ignored her. Since then we have heard through the grape vine that her and 4 others were found dead and had OD'd and that 1 had been arrested for charges related to drug dealing. We found out this shortly after the new batch of residents moved in.

The worst of the new residents is a 6'+ schizophrenic man. Since we were inactive last time and the worst outcome happened, we are assuming that our action now can't make anything worse.

Originally we tried to resolve with public housing authorities but were unable to make any progress. After that we called our local police station a few times to report incidents and were then told that these incidents are serious enough to call the emergency line so that is what we have been doing.

I don't believe they are aware that we are the ones calling, but if they do I was probably going to look into some kind of restraining order if the threats were against me personally (I'm not sure if this would be possible and assume it would be a nightmare process)

My whole takeaway from this situation has been

A) if they are not fit to be in society it is safest for everyone (including them) if they are removed.

B) call early. If a situation begins, call the police. They are having an episode and it's going to escalate. If you're lucky they'll rock up during the escalation.

C) don't try to sympathise with their situation. Focus on your situation. You deserve to not have your quality of life impacted by them.

Apologies if I seem cold, I'm just mechanical about this situation non