 The film is based on a true story. While she was living in Hollywood  with her husband, writer Romain Gary (qv), actress  Jean Seberg (qv) brought home a large white dog she had found on  the street that seemed friendly and playful. However, when the  animal saw her black gardener it attacked him viciously, injuring  him. Afterwards they kept it in the back yard, but one day it got  out and attacked another black man on the street but no one else.  After this happened a third time they realized that someone had  trained the dog to attack and injure only black people. Gary wrote a  story about it, and eventually Samuel Fuller (qv) read it and made  it into this movie.