California Penal Code 211 covers armed robbery (561 has to do with court or was just made up for the movie). Code 3 is a radio code for a police vehicle using its red light and siren (Los Angeles Police Department regulations at the time allowed only one police car to go Code 3 at any one time). Penal Code 502 covers drunk driving.
After the connection is made between Yvonne and one of the robbers, Det. Ryan references Norman Mailer's 1948 novel "The Naked and the Dead", saying they are " . . . the naked and the dead". The film of Mailer's novel , The Naked and the Dead (1958),l would not be made for 16 years.
The airplane Purvis chartered is a 1941 Beech AT-11 "Kansan", registration N66647. This particular plane was used by the USAAF in WWII, and then sold as surplus to a private firm after the war. This same plane can be seen in Johnny Allegro (1949).