The Drop by Michael Connelly

Detective Harry Bosch and his partner, David Chu, are given the case of the 1989 murder of college student, Lily Price. They work as part of the Los Angeles police department's Open-Unsolved Unit and are asked to delve into this case again because there's been a recent DNA hit from the lab. The problem is that the DNA is from a man named Clayton Pell, who was eight years old at the time of Lily Price's death. Knowing that Pell can't be the killer, they wonder if the lab messed up the results. If so, it could cast a pall over cases decided by DNA in Los Angeles County. Bosch is then surprised when his former department nemesis (and now L.A. councilman) Irvin Irving requests that he head the investigation into Irving's son's death at the Chateau Marmont. It first looks like suicide, but Bosch isn't too sure. By featuring two interesting cases, having Bosch battle the bureaucracy and politics of the LAPD and giving insight into his personal life, Connelly has made this one of the best books of the series. It will be published next month.