Monsieur Verdoux

From Wikipedia:
Monsieur Verdoux is a 1947 black comedy film directed by and starring Charlie Chaplin.

The film is about an unemployed banker, Henri Verdoux, and his sociopathic methods of attaining income. While being both loyal and competent in his work, Verdoux has been laid-off. To make money for his wife and child, he marries wealthy widows and then murders them. His crime spree eventually works against him when two particular widows break his normal routine. The film ends as Verdoux is being led to the guillotine in the prison courtyard after defending his actions as no worse than those carried out every day throughout human history, differing only in scale.

The New York Times just this week did an in-depth article on this movie.