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 as a tourist attraction after his death. According to Simone, Manson believed he would never die, and may simply have used the possibility of marriage as a way to encourage Burton and Hammond to continue visiting him and bringing him gifts. Together with co-author Heidi Jordan Ley, and with the assistance of some of Manson's fellow prisoners, Simone wrote a book about Manson and was seeking a publisher for it. Burton said on her web site that the reason the marriage did not take place is merely logistical. Manson was suffering from an infection and had been in a prison