City Of Bones by Michael Connelly
When the bones of a twelve-year-old boy are found scattered in the Hollywood Hills, Harry Bosch is drawn into a case that brings up the darkest memories from his own haunted past. The bones have been buried for years, but the cold case doesn't deter Bosch. Unearthing hidden stories, he finds out the child's identity and reconstructs his fractured life, determined that he not be forgotten.
At the same time, a new love affair with a female cop begins to blossom for Bosch - until a stunningly blown mission leaves him in more trouble than ever before in his turbulent career. The investigation races to a shocking conclusion and leaves Bosch on the brink of an unimaginable decision.