Peter Kürten was a German serial killer, known as "The Vampire of Düsseldorf" and the "Düsseldorf Monster", who committed a series of murders and sexual assaults between February and November 1929 in the city of Düsseldorf. In the years before these assaults and murders, Kürten had amassed a lengthy criminal record for offences including arson and attempted murder. He also confessed to the 1913 murder of a nine-year-old girl in Mülheim am Rhein and the attempted murder of a 17-year-old girl in Düsseldorf.

Robert Hossein was a French film actor, director, and writer. He directed the 1982 adaptation of Les Misérables and appeared in Vice and Virtue, Le Casse, Les Uns et les Autres and Venus Beauty Institute. His other roles include Michèle Mercier's husband in the Angélique series, a gunfighter in the Spaghetti Western Cemetery Without Crosses, and a Catholic priest who falls in love with Claude Jade and becomes a communist in Forbidden Priests.