CHICAGO - Buying 2 Flat - How to do due diligence

[Robert Obniski]

I looking to purchase a 2 flat in the chicago area and be a live in owner. It's an off market deal through a wholesaler. One of the requirements is a $10k non refundable earnest money deposit. 

Like all deals the seller is having the buyer do all his own inspections and due diligence. 

My question is... what is the best way to go about checking if there are any violations or unpaid fines that can be carried over to me? I basically want to know what outlets i use or call or whater to cover my own a$$?

There are no contingencies in this deal so I need to get it right the first time.

Please share your wisdom BP!!