With a Vengeance

At first the murder of Nelson Jamison seemed fairly straightforward. He had been strangled, but next to his corpse lay a hand-printed card with the words The Vengeance is Just. Jamison, a rich ne'er-do-well, has a prison record for rape, and everything pointed towards a victim's revenge killing. But within hours Lieutenant Luis Mendoza and his team have an identical killing on their hands, and then a third. But is the killer about slip up and reveal their identity?