Filmed in 1961, not released until 1963.
Although Max Steiner received screen credit as composer, he did not write any original music for the picture. Cues from his previous Warners scores were used.
The film was made with the FBI's cooperation. Intended as a TV pilot for a series about the agency, it was released in theaters instead. The format was reworked, and a year after the film's release in the USA, the TV series The F.B.I. (1965) was launched.