The Crossing by Michael Connelly

Harry Bosch, getting bored in his retirement from the LAPD, reluctantly decides to cross over to the "other side" to work for his half-brother, Mickey Haller, the defense attorney for reformed gang member, Da'Quan Foster. Haller believes that Foster is innocent of the murder of Lexi Parks. With his background, Bosch is able to secretly get information about the case and also view the investigation through the prosecution's and police department's eyes. However, someone is watching Bosch's and Haller's every move--making their actions even more dangerous. The Crossing is another hard-to-put-down adventure featuring Harry Bosch.