In Tucson, when a homeless woman is brutally gutted under a highway underpass, the suspect's motive haunts investigators. And in Tulsa, the shooting of a man in an apartment sets off a chain of events unlike anything Tulsa Homicide has ever seen.

This episode looks back at three cases that stayed with detectives. In Dallas, a man is dismembered and burned and dumped in a lake. Then, in Tulsa, two kids find their mother dead in her car. And in Dallas, two friends are found burned in a car.