Frenzy actual London serial murder cases: the Christie murders in the early 1950s, and the Jack the Ripper murders in 1888. Barry Foster has said that, in order to prepare for his role, he was asked by Hitchcock to study two books about Neville Heath, an English serial killer who would often pass himself off as an officer in the RAF. "Frenzy" was the third and final film that Hitchcock made in Britain after he moved to Hollywood in 1939. The other two were "Under Capricorn" in 1949 and "Stage Fright" in 1950 (although there were some interior and exterior scenes
Themes and plot devices in Hitchcock films associated with violent behavior. In "The Lodger" and "Psycho", this association is the whole basis of the film. Biographers have noted how Hitchcock continued to challenge film censorship throughout his career, until he was allowed to show nudity in "Frenzy". Hitchcock had a dramatic preference for blonde women, stating that the audience would be more suspicious of a brunette. Many of these blondes were of the Grace Kelly variety: perfect, aloof ice goddesses, who also have a hidden red-hot inner fire. In "Vertigo" James Stewart forces a woman to dye her hair blonde. One of Hitchcock's earliest films, "" (1927),