Le Dossier noir (1955)
Directed by André Cayatte

Film Synopsis

Recently appointed a magistrate, Jacques Arnaud arrives in Lancourt, a small provincial town which is under the control of Boussard, an scrupulous businessman.  Arnaud's first client is Dutoit, who rears German sheep dogs for a living.  Dutoit  reports that someone has been poisoning his dogs.  Could it be the same person who has recently broken into his house to steal a black file drawn up by his friend Le Guen just before he died, a file that implicates Boussard in fraudulent speculation?   Suspicious, Arnaud begins by exhuming le Guen's body; the autopsy reveals the presence of arsenic.  Acting under the influence of Boussard, Inspector Franconi begins his own investigation with the intention of establishing Dutoit as le Guen's killer.  Meanwhile, Inspector Noblet arrives from Paris with another hypothesis.  He believes that le Guen was murdered by his wife, Françoise, after she had had an affair with her brother-in-law Gilbert...