Robert Aldrich earned so much money off the back of his film The Dirty Dozen (1967) that he was able to buy his own film studio and make the kind of films he wanted to make. Unfortunately the first three that he made independently (The Killing of Sister George (1968), The Legend of Lylah Clare (1968) and Too Late the Hero (1970)) were all box office flops. When this movie also crashed and burned at the box office in 1971, Aldrich was forced to sell his studio and go back to being a director for hire.
One of the key props in the film is a diamond necklace. Because of Robert Aldrich's insistence on accuracy, this was a real diamond necklace, that came complete with a special female courier, disguised as a secretary, and with an escort of guards on the set. Special arrangements were made with the local bank and sheriff's department in the location of Placerville, California, while the necklace itself was transported by a motorcade of vehicles.