The 6th Target by James Patterson

These excerpts primarily follow Sergeant Lindsay Boxer and her colleagues, including Inspector Warren Jacobi and Inspector Richard Conklin, as they tackle two major San Francisco cases. The first involves the aftermath and trial of Alfred Brinkley, the man responsible for a mass shooting on the Del Norte ferry that severely wounded Boxer's friend, Claire Washburn, and killed several others, with the prosecution battling Brinkley’s insanity defense. Simultaneously, the team investigates the high-profile abduction of young Madison Tyler and the murder of her nanny, Paola Ricci, which leads them to uncover a human trafficking ring operated by Paul Renfrew and his wife, and also track down a serial attacker in Boxer's friend Cindy Thomas's apartment building, Garry Tenning, who is motivated by extreme noise sensitivity. Throughout these events, Boxer is navigating a personal demotion and dealing with a complicated romantic relationship with Joe, who attempts to transfer to San Francisco.