True American crime that has influenced movies and books?

I am researching true American crime that has been the basis for a movie or a book. It is for an extended project in college. I am beginning with movies and books based upon organised crime, gang crime, and serial killers. I am gathering real case studies from TV, my library and the internet. It would be a help if anybody could give me any movies or books they know of that I may have missed. It would be more beneficial if they were way out or fairly unknown, but they must be based upon true crime.True American crime that has influenced movies and books?Research Ed Gein.
The story of Ed Gein has had a lasting impact on western popular culture as evidenced by its numerous appearances in movies, music and literature. Gein's story was adapted into a number of movies, including Deranged (1974), In the Light of the Moon (2000, later retitled Ed Gein for the U.S. market), and Ed Gein: The Butcher of Plainfield (2007). Gein served as a model for several book and film characters, most notably such fictional serial killers as Norman Bates (Psycho), Leatherface (The Texas Chainsaw Massacre), and Buffalo Bill (The Silence of the Lambs