Watch VoirFilms. Jean-Francois Abgrall, today the head of a private detective agency, was just a simple provincial gendarme back in 1989 when he was assigned to investigate a murder on a beach. Instead, his investigation put him on the trial of one of France's most terrifying serial killers, Francis Heaulme, who for eight years wandered the country committing some of the most brutal murders in the annals of modern crime. This is the true story of that manhunt, a tale of terror, suspense and determination.