Although the plot is mostly fiction, Wyatt Earp and Tom Mix were real-life friends. After Earp retired from law-enforcement, he and his wife drifted around, eventually setting in Los Angeles, where he and Mix met. Mix tried to get Hollywood to produce a movie about Earp, but they weren't interested. Earp was hired as a technical consultant for movies starring Mix and William S. Hart. When Earp died in 1929, Mix and Hart were his pallbearers.
According to "James Garner: You Ought to be in Pictures", Garner said, "I'd never work with Bruce Willis again. I did that Blake Edwards film with him, Sunset (1988). Willis is high school. He's not that serious about his work. He thinks he's so clever he can just walk through it, make up dialogue and stuff. I don't think you work that way".
Some movie posters featured a blurb that said, "They broke every rule, loved every woman, took every risk and solved the most shocking murder in the history of Beverly Hills. And it's all true. Give or take a lie or two".
Alfie Alperin was loosely based on Charles Chaplin. Like Chaplin, Alperin was a comic actor who became a director, producer, and studio head. Alperin's screen character of "The Happy Hobo" was based on Chaplin's "The Tramp".