The Snorkel

The name of this movie is The Snorkel released in 1958-07-07 and it's main theme is Jacques Duval devises a fiendishly clever method of murdering his wife. Doping her up with sleeping tablets, Duval places his wife in a sealed room, then opens all the gas jets. While the police identify the body, Duval remains hidden in the room, breathing through a snorkel, then makes his escape when the authorities leave. Only one flaw in this perfect crime: Duval's stepdaughter Mandy Miller is the suspicious type..