Jamesht

The Byrne and Balzano series by Richard Montanari I highly recommend. It focuses quite heavily on the psychology of the killer and is extremely well written. A stand alone book I would advise is Gangster by Lorenzo Carcaterra. It follows the life of Gabe from his beginnings in Italy all the way to becoming part of the American underworld of organised crime. It's simply one of the best stories I've read this year.