Three cases that look at what happens when people become obsessed with revenge. In Cleveland, a man is gunned down in broad daylight and detectives learn it could be connected to another homicide. Then, in Harris County, a teenage girl is lured to her death by someone she considered a friend. Finally, in Louisville, a man filled with rage unleashes a cascade of bullets on a house full of sleeping people.

Three homicide cases that examine how and why some women kill. In Tulsa, a woman is shot just outside her home and detectives are shocked by their suspect. In Birmingham, a mother of three is shot in front of her young children. And in Charlotte, when a couple is suspected of stabbing a man in his car, detectives need to determine who is telling the truth.