Angel Face (1952)

This is really good noir directed by one of the best, Otto Preminger. I particularly like Jean Simmons playing against type as the bad girl.

Robert Mitchum is Frank, an ambulance driver who meets 19 year-old Diane when her step-mother almost dies from a gas leak. Diane hits on him, steals him from his girlfriend, and brings him on as chauffeur in the home of her father and rich stepmother. Frank soon understands that Diane wants to kill her stepmother, and he leaves. But the stepmother dies, and Frank is implicated in the murder. They get married to have a better defense, but Frank now hates Diane. Will she let him leave, though?

There are some great lines in old noir, like this one:  Is it a complicated thing, or could anyone do it, even a woman?

Funny - murder is too complicated for a woman? Noir tells us again and again that that is so much hooey.