Three cases from The First 48 that were driven by revenge and resentment. In Mobile, a man is executed in a parking lot months after an altercation; in Harris County, TX, pressing charges in an attempted robbery leads to a man's brutal murder; and in Tulsa, a gang member goes on the hunt after being called a name.

Friendship is usually a good thing--but when it goes bad, it can be fatal. Detectives in Atlanta find a woman's body in a trashcan; in Louisville, a domestic dispute turns into a homicide investigation; in Birmingham, doing a favor for a friend costs one man his life.