In Tucson, a grandfather is shot after answering a knock at his front door. The suspect's getaway car crashes a few blocks from the crime scene and the suspect flees. Det. Bill Hanson and his team hope that clues from the car will lead them to the alleged killers.

In Cincinnati, Detectives Jenny Luke and Terry McGuffey investigate the murder of a 56-year-old man brutally beaten to death in the stairwell of his apartment building. Luke tracks down two teenage suspects and is surprised to learn what triggered the deadly fight.