Tenant is suing me. Legal advice needed

[Maciej G.]

Hey guys

I would like to ask for a legal advice.

Year ago I screened a tenant and except for a bankruptcy and finding out he used to a lawyer whom license got suspended I decided to give it a shot. I own 6 unit building in Chicago with non conforming attic unit (which I rented to mentioned tenant). When the summer last year came and attic started to get hot it was the first time he threatened to sue me, I panicked and immediately hired a company to insulate the attic, and waived his rent for that month. That kept him happy for a while, next issue was when his power started going out due to not enough power supply to the unit, I called electricians but he did not let them in saying he was busy. Almost a year later 3 weeks before his lease expiration he begged me to extend for additional 2 months which I gently rejected because I already have tenant in place plus I don't want to deal with this person ever again, and thats when everything started... He bought big speakers and decided to play the music up until 4 am . My other tenants used to tolerate this but quickly got fed up due to lack of sleep. They started flipping his breakers, in return he started flipping breakers to all units. At some point he met with my other tenant who lives in the apartment directly under and threatened him with a gun. We called the police and got the report, my tenant was shocked had to take sick days off work due to insomnia caused by stress and loud music. I never touched his breakers but at one point I caught him drunk messing with breakers and I filmed it. When I told him about this evidence he sent me somewhat informal email saying that he demands compensation for his electronic equipment that was damaged due to the power outage, and legality of the unit in which he stayed. This looks like a step before taking me to court. He still plays loud music at night and my tenants cant sleep because of it.
I would like to thank to everyone who made it this far, I know I have lots to learn about managing the property and please don't say things like "hire a manager" because those are the things I already know but I still want to learn as I am a firm believer that "Still sea never made a good sailor" I would like to ask you for either your advice on how to solve this or contact to some legal advisor that could help me in this case,