Blake Edwards intended originally simply to produce this film, with William Friedkin directing. Friedkin turned it down because he disliked the script - something its co-writer William Peter Blatty reminded him of after they had later collaborated successfully on The Exorcist (1973).
The plot of this film derives from the very first episode of the Peter Gunn (1958) television series, even using some of the same dialogue - although it has been greatly expanded and makes use of plot details which would never have been permitted on American television in the 1950s.
The piano player seen briefly at the Ark nightclub is famed composer and band leader Henry Mancini, who collaborated with director Blake Edwards on numerous films.