Detective Harry Bosch receives a report from a member of the LAPD Data Evaluation team — they've found a case-to-case hit while analyzing data. The same witness has been listed across two unrelated homicide cases. In one case, a precious-metals swindler was murdered in the garage of his apartment building. In the other case, a man awaiting trial for his alleged rape of a teenager was shot dead in his garage. The witness present in both cases was Diane Gables, who testified in the first case to driving past said apartment building garage and seeing a man running away with a gun. She was also caught on a red-light camera a couple of blocks away from the location of the second murder, just after the murder occurred. Bosch and another detective, Edgar, make the trip out to Diane Gable's house. They question her in her living room — Bosch suspects Diane is responsible for both murders. Diane's story, however, remains exactly the same as it did five years ago. At 9am two days later, Bosch arrives again at Diane's house. When she doesn't answer the front door, Bosch slips around to the back and lock-picks the back door. Bosch locates Diane's home office and opens the blinds over a row of filing cabinets. As he is lock-picking one of the cabinets, he hears Diane's voice behind him, telling him not to move. She is pointing a handgun at his head. They talk, and Bosch says that he's not afraid Diane will shoot — she only shoots the predators, the bad-guys. Diane says she could think of him as a bad guy, since he broke into her house without a warrant — but Bosch pulls one out of his pocket and shows it to Diane. A judge had signed the warrant based on Diane's proximity to both murders as well as a lie she told during her interview with Bosch and Edgar. Diane starts to raise her gun, and Bosch tells her to be careful — all he has to do is say one word. Diane jolts as she notices the red laser dots on her forehead and chin from the SWAT sharpshooters across the street. Diane raises the gun up, but Bosch doesn't say the word — he does not think she will shoot. Suddenly, though, a bullet shatters through the glass window into Diane's heart, and she drops down to the floor. Bosch yells, saying that he didn't say the word, that they shouldn't have shot. As she dies, Diane tells Bosch that she killed nine people total. Diane dies.