The First 48: Revenge Kills

A recent high-school graduate is shot and left to die in his father's arms; a man may have taken revenge on a childhood friend.

Miami homicide detectives investigating a triple shooting on a crowded bus learn the violence was the result of an escalating street war.

Homicide detectives wander into a dark world of drugs and prostitution to solve an execution-style murder in a motel parking lot.

A schoolyard fight between two teenagers leads to the shocking murders of a 29-year-old man and his paralyzed mother.

An unidentified girl found shot to death in a Dallas field; residents of a Cleveland community help police search for a young father's killer.

A New Orleans father and his friends are ambushed while sitting in a parked car.

The target of a drive-by shooting in Tulsa, Okla., walks away from the attack, while his girlfriend is not so fortunate; police uncover a long-simmering feud as they hunt for the killer.

A Kentucky police detective searches for the person who killed a man in a wheelchair; a Charlotte, N.C., man found stabbed to death in his car.

A drive-by shooting claims the life of the founder of a street gang; fearful friends keep quiet after a teenager is shot.

A feud between households in an Atlanta apartment complex leads to the fatal shooting of a promising boxer.

A young man is murdered outside a liquor store in Memphis, Tenn.; an elderly man is duct-taped and beaten to death outside his Miami home.

In Memphis, Tenn., a truck fire brings the homicide team to the scene of a double murder; a woman in Kansas City, Kan., is found dead in the street.

When a Cleveland man is shot in front of his family shortly before Christmas, police detectives suspect drug dealers may be involved.