If you're looking for a Chicago themed book how about a book by a former Chicago Police officer, Jerry Ardolino. Entitled Extreme Cop: Chicago PD: The True Story of the Wildest, Most Violent Cop in the History of the Chicago Police it almost reads like it should be an action film. Well at least if you believe the introduction.
In fact I wouldn't be surprised if an action movie was in the works. Although in some respects it could be more realistic than anything Hollywood could devise. In any event I just read the intro to the book by the author I didn't buy it, but if I had to make a purchase for this book I would have. Perhaps you should as well.
Here's an official website.