Now the victims could possibly sue you because you knew he was violent and making threats but you did nothing.

If the second story is true, she may be scared of a violent ex-boyfriend.

What your other tenants think is very important. 2) The type of person that has pit bulls has a TENDENCY to be more violent and fearful, they often use the petas a threat or weapon.

Also, the closer you are to downtown Chicago, I find the tenant pool to be of a higher standard and less violent crime.

If they are violent, call the police. 

What do you think would happen if your tenant acted violently against the neighbor while you're still waiting on the courts?

A - this is where you and I want to live (lowest crime, best schools); appreciation is very good (generally highest) and cashflow is either negative or very little; ideal for fix n flips if you find that "sore thumb"; best for new buildsB - low crime, good schools; with some appreciation and positive cashflow; lots of homes are owned by first time home buyers in addition to renters with stable jobs/ good incomes; good for fix n flips as wellC - some crime, OK schools; little appreciation and very good cashflow; renters with OK incomes; ideal for buy-and-hold specially if area is changing or becoming a B area; you can get very good ROI even for turnkey properties if you're in this areaD - high crime, bad schools; no appreciation and very high cashflow; mostly subsidized housing; to succeed with this, you got to be a "hands on" landlord and literally live close by; lots of boarded up houses (one boarded up per block)F - this is where the most violent crimes are committed; negative appreciation and the highest cashflow; every other house is boarded up; you either get shot or get stabbed so be careful so wear a bullet proof vest:) PMs don't even want to be in these areas

Likely because they did not want to have to deal with violent felons, drug dealers, and/or sex offenders.

I made over $1M on a 48-unit building that in a D area that became a C area (over a 6-yr period).However, if the OP is a newbie investor, I would recommend staying away from F areas.This area though does not sound like an F area (aka War zones).War zones are where 90% of violent crimes in the city happens (murder, rape, etc).

I only invest in multi-family and don't let potential tenants with violent histories in my properties, but if you're comfortable with letting one of these tenants in I would check and see if either can get a co-signer as that will help minimize the low credit score and you can go after the co-signer (as well as the tenant) in the event there's an issue with rent or damage to the rental.