Dark Sacred Night

I have been a long-time fan of Michael Connelly's "Harry Bosch" and "Lincoln Lawyer" books (see several posts in my blog); although I haven't come close to reading all 34 of his novels. This is the 21st book in the Harry Bosch series and the 2nd to feature Renée Ballard. In this book, Harry Bosch, to Renée Ballard, a detective who has been banished to the "Late Show" (night shift) at the Hollywood station after filing a sexual harassment complaint against a commanding officer. Harry is investigating a very cold case on his own dime--the murder of a 15-year-old street prostitute, Daisy Clayton, nine years ago. Harry is semi-retired but "consulting" for San Fernando police department on their cold cases. This one is personal for Harry who has helped Daisy's mother, Elizabeth, get off drugs and is currently letting her live in his spare room to support her in staying clean. She is tormented by her failure as a mother and Harry hopes to solve the murder and give her some closure.
Renée comes back from supervising a death scene one night and finds Harry going through old files in the squad room. After he leaves, she realizes he has broken into the file cabinet containing the murder book for Daisy, and begins to investigate on her own. They eventually combine forces after some lengthy dancing around over whether or not to trust one another. They are both loners with a strong sense of justice and a particular investment in abused women. We get a fair amount of what seems to be peripheral digression into other cases that each of the detectives are working on, although some of them do eventually tie back into the main case. 
A review from NPR's Maureen Corrigan in The Washington Post calls the book "darkly brilliant" because neither Harry nor Renée are ever going to win "the glass half-full" contest, but they make a really good team. A favorable review from Kirkus,  and the New York Journal of Books says, "Michael Connelly remains the reigning heavyweight champion of police procedurals, and Dark Sacred Night is another knockout victory."We are currently watching Amazon Prime's TV version of the Harry Bosch novels (called just "Bosch") and they are well cast and well done.