Just finished reading Spade & Archer, a prequel to The Maltese Falcon written by Joe Gores in 2009 or so. It's pretty good, it definitely *feels* like a Sam Spade book! The only problem I have with it is it uses "could of" and "should of" and whatnot and that's... wrong. Very wrong. The words your looking for are "could've" and "should've" or, depending on how slangy you want to be, "coulda" and "shoulda".
...anyways, it was a good book. Except for that one thing.