Echo Park is the 17th novel by American crime-writer Michael Connelly, and the twelfth featuring the Los Angeles detective Hieronymus "Harry" Bosch.

Thirteen years later, Bosch works in the Open-Unsolved Unit at Parker Center, going over cold cases with his most recent partner, Kizmin "Kiz" Rider.

A serendipitous traffic stop in Echo Park results in the arrest of Raynard Waits after body parts are found in his van.

Waits soon confesses to a string of slayings involving prostitutes and runaways, as well as to two earlier murders: that of pawnshop owner Daniel Fitzpatrick during the 1992 riots, the other of Marie Gesto.

When the Gesto case files are reexamined, it seems that Waits had called the police shortly after the murder, pretending to be a tipster, but Bosch and Edgar never followed up on it.

Bosch suspects Waits felt comfortable in Echo Park, and that the investigation into his crimes had overlooked an important connection to this neighborhood.

Under questioning, Waits confesses to killing Fitzpatrick as a random act of violence, and to raping and strangling Gesto the following year due to her fitting his fantasy.

Bosch, Rider and an LAPD investigation team accompany Waits and his attorney, Maury Swann, to an isolated area in Beachwood Canyon where human remains are buried in a shallow grave.

Also, while examining copies of case files he made before quitting the LAPD several years earlier, Bosch discovers no evidence that Waits contacted police after Gesto disappeared.

He suspects that the "51 sheets" (typed summaries of handwritten notes) were altered to make Bosch appear responsible for allowing Waits to escape notice.

Waits, Bosch thinks, was not guilty of the Gesto murder but played along to avoid execution and hoping for a possible chance to escape.

Bosch and Walling also discover evidence that Fitzpatrick was not a random victim: he had been murdered by a disgruntled customer who soon afterwards falsified a birth certificate to change his name to Raynard Waits.

Bosch reluctantly decides that letting Pratt walk is a price worth paying to finally catch Gesto's killer.

Walling confronts Bosch with her suspicions that he orchestrated the shooting of Pratt, having known that Anthony was hot-tempered and had a concealed carry permit due to his job as a security guard.