The Cook County Human Rights Ordinance: This ordinance prohibits people in Cook County (including employers, landlords, property managers, real estate agents, store and restaurant owners, bankers, lenders and Cook County government officials and employees) from unlawfully discriminating against or harassing other people on the basis of that person's race, color, sex, age, religion, disability, national origin, ancestry, sexual orientation, marital status, parental status, military discharge status, source of income (including use of a housing choice voucher), housing status, or gender identity.

Also, there is a tenant in another unit who is a sexual offender of small children.

I approached her and she evicted me. unfortunately I was stuck with nowhere else so I lived with it until her son sexually assaulted me.

There's a controlled, pre-existing relationship (likely of a sexual character - but I don't know you and I'm not assuming) between the agent selling the property and the inspector who assesses its quality. 

The reason for the background check is I would like to know who I have living on my property, sexual predators, past criminals, I want to know.They are actually considerably below market rents for their unit and the area, I mean like $500 dollars a month below average.  

There is a park in my area that will not rent to sexual offenders.  

When 1 out of 4 girls & 1 out of 6 boys are sexually assaulted by their 18th birthday, there are a TON more sex offenders out there than what state websites show, because most are never caught & convicted. 

My wife volunteers at a women's crisis center that deals with sexual violence.

(Recommend Misbehavior of Markets by Mandlebroit and anything by Nassim Taleb on a tough but fair commentary on we economist.)A prime example of how even economist don't agree is the interest rate forecast.  

Many people don't know that in addition to national fair housing law, states and municipalities may have additional protected classes (for example, in Austin TX we have local additions to fair housing that cover sexual orientation, status as a student, and others)There are resources from the national apartment association (and through many state and local associations) specifically geared to educating and supporting independent rental owners (usually regarded as having less than 100 units).