The scene in which the Cop hands over information to the Detective was filmed 2 blocks away from where William Holden was found dead in Santa Monica, CA.
The famous 'street performers' who frequent Hollywood Boulevard make an appearance near the opening of the film.
Numerous takes were required in the scene between the Detective and the Mystery Girl. She would answer the door, but every time she did, the Detective would say something off the cuff causing laughter on the set.