The Drop by Michael Connelley

Harry Bosch's long career as a police detective is winding down.  He has just been informed that he's been granted a three year extension on his request to remain past retirement.  He is working in the Cold Case division with a partner, Cho, for the last two years.  Harry doesn't care.  He just wants to work cases.

He and Cho are given a case that morning.  An old murder has had a DNA hit.  Blood has been found on the belongings of a murder victim from twenty-one years ago.  When the two men look up the DNA's match, they find it belongs to a convicted rapist.  Easy win.  But then it turns out that the man only raped young boys.  It also turns out that at the time of the murder he was only eight years old and thus unlikely to be their man.

On the same day, Harry is called upstairs.  Irvin Irving was a policeman who was forced out.  He then ran for city councilman and won.  He has since spent his life making life miserable for the police department he now despises.  But today he has requested Harry.  Irving's only son has been found dead as the result of a fall from a hotel balcony.  Was it suicide or was he pushed?  Irving dislikes Bosch but he knows Bosch is about the best at what he does.  He insists he wants to know the truth and Harry is assigned to discover it.

This is the seventeenth Harry Bosch novel.  In this one, Harry struggles with the winding down of his career, the new responsibility of raising a teenage daughter by himself, and as always, with his relationships inside the department and in his personal life.  Readers will be caught up in the police procedure and the workings of a master detective's mind.  This book is recommended for mystery readers.