The Day of the Dolphin originally going to be directed by Roman Polanski for United Artists in 1969, with Polanski writing the script. However, while Polanski was in London, England, looking for filming locations in August 1969, his pregnant wife, the actress Sharon Tate, was murdered in their Beverly Hills home by disciples of Charles Manson. Polanski returned to the United States and abandoned the project. The following year it was announced Franklin Schaffner would make the movie for the Mirisch Corporation. These plans were frustrated and Joseph Levine ended up buying the project from United Artists for Mike Nichols. The film was mostly shot
Charles Manson on as apprentices. Manson was arrested two weeks later during a nighttime raid on a Peoria store. In the investigation that followed, he was linked to his two earlier armed robberies. He was sent to the Indiana Boys School, a strict reform school. He later claimed that other students raped him with the encouragement of a staff member. Manson developed a self-defense technique he later called the "insane game". When he was physically unable to defend himself he would screech, grimace and wave his arms to convince aggressors that he was insane. After a number of failed attempts, he escaped