True Detective

I recently read a book by Max Allan Collins, Quarry, and although it wasn't my favorite book of all time, I was sufficiently intrigued to order the DVD of the TV series that was made from that book and this first book in Collins' "Nate Heller" series, which won a Shamus award. See more info about Collins on his blog and in my post for Quarry.
Set in 1933 Chicago, just a year before the opening of the World Fair, Nathan Heller is a detective for the Chicago Police Department, thanks to his uncle Louis putting in a good word to get him on the force in the first place, and also due to his being willing to lie about who killed a journalist/ gangster. But Nate does have standards and when he gets unwillingly dragged into yet another dirty trick on the part of the Chicago PD and the mayor, he decides to quit and go private. Two detectives who are in the pocket of Mayor Cermak drag him along to roust a bookie joint run by Frank Nitti and in the process Heller kills a young man in self-defense. One of the detectives shoots Nitti and then wounds himself claiming that he shot Nitti in self-defense. Nate knows otherwise and the pressure is on for him to lie again in the upcoming investigations. If he agrees, the mayor will let him get his PI license; if Heller insists on telling the truth, he won't be able to work. In this novel, fictional protagonist Heller is friends with a number of real people including Eliot Ness of FBI fame and Barney Ross, the lightweight boxing champion. He meets FDR, George Raft, and Al Capone. There are a lot of colorful characters in the book because there were a lot of big personalities fighting for control in Depression- and Prohibition-era Chicago. It's hard to be an honest detective in a pervasively dishonest system and much of the book deals with Heller's ongoing efforts to draw a line and still stay alive. The book is typical of the hard-boiled detective genre and is very atmospheric in describing Chicago of the 1930's. I frequently read the acknowledgements and Collins lists dozens of books he consulted to get the historical details for his book. A much more detailed plot summary and a less-than-laudatory review from Kirkus is here.