Concrete Blond by Michael Connelly
Series featuring Harry Bosch
They called him the Dollmaker, the serial killer who stalked Los Angeles call girls and left a grisly calling card on the faces of his female victims. With a single faultless shot, Detective Harry Bosch thought he had ended the city's nightmare. Now, 4 years later, the dead man's widow is suing Harry and the LAPD for killing the wrong man. This accusation rings terrifyingly true when a new victim is discovered with the Dollmaker's macabre signature. Now, for the second time, Harry must hunt down a death-dealer who is very much alive, before he strikes again. It's a blood-tracked quest that will take Harry from the hard edges of the L.A. night to the last place he ever wanted to go — the darkness of his own heart.

I had read a later story featuring Bosch and wanted to know more about him. He has a very complicated background and we learn why he has such a hard time opening up to women. His own mother was killed in an un-solved crime when he was 12 years old. He spent the rest of his teenage years in foster care or a boy's home. He is not the cop out there but he does try to bring justice to the dead.

Connelly writes in a very interesting voice. Will need to catch up!

Earlier titles in the series:
Black Ice
Black Echo