Forbidden to Know
Défense de savoir (original)
When the police find Simone seated near her husband's corpse it is predictable that she is charged with the murder. Jean-Pierre Laubray is appointed counsel for the defence. He begins an inquiry into the case and he finds out that the murdered man had killed a barman in a robbery the night before. He finds out as well he was a leg-man of Cristiani's for his election campaign. He tries to contact Juliette, Cristiani's daughter, and he discovers that Bruno, Juliette's brother, also died that same night in a car accident...
Starring Jean-Louis Trintignant, Michel Bouquet, Charles Denner, Juliet Berto, Bernadette Lafont, Marie Trintignant
Watch "Forbidden to Know" on Netflix released in 1973. It's a crime and drama movie, and has a rating of 5.8 out of 10 from Imdb which is fairly okay for this kind of movie.