Colette Régis

Séverine and her husband Roubaud kill their former employer in a train. Engineer Jacques watches them, but doesn't tell the police, because he's in love with Severine (imdb)

Grozo, an ambitious and lecherous man saved from the gallows, is employed by the Governor in the kennels; his envy of both the latter's position and wife sends him on a spiral of murder and deception till he has replaced him on the 'throne' and intends to take Glossia for himself. (imdb)

A wealthy and bored woman (Moreau) is witness of a murder in affection and meets another witness (Belmondo). She asks him about the history of the victim and falls in love with him. (imdb)

Peter is a laborer who dons fancy clothes and cruises the seedy dives of Dusseldorf for women. Whenever he is rejected by one of the females, he turns into a sadistic murderer. A shy young cabaret singer falls for Peter, but she too becomes a victim of his rage.

Whilst moving into her new apartment in the rue Picpus, Madame Dumont discovers a dead body in her wardrobe. Inspector Maigret is called in to investigate…