The Witness is a French-Italian crime-thriller film. It is loosely based on the novel Shadow of a Doubt by Harrison Judd.
Italian artist Antonio Berti is invited by his French friend Robert Maurisson to restore the paintings in the Reims Cathedral. He needs a model and selects Cathy, a teenage girl from the local church choir. Despite her angelic demeanor, the girl makes sexually explicit comments while posing for Antonio. One day, Cathy goes missing, and her dead body is later found in a canal, not far from an empty house owned by Maurisson. Antonio remembers seeing his friend Robert near the house on the night of the crime, but the latter denies it and has an alibi. Instead, the police turn their attention to Berti who is an outsider and can't provide an alibi. Later, Robert privately confesses to Antonio, and suggests they both would escape to a country that doesn't have capital punishment. Cathy's father then mistakenly assassinates Maurisson, who was driving Berti's car. Having lost the only person who could prove his innocence, Antonio is convicted and sentenced to death.
Written and directed by Jean-Pierre Mocky and starring Alberto Sordi and Philippe Noiret.