Dial M for Murder (1954)

Revealing mistake: Just before Anthony Dawson is going to be stabbed to death by Grace Kelly with a pair of scissors, you can see for a very short moment that the scissors are already attached to his back.

Mark Halliday: What is all this?
Chief Insp. Hubbard: They talk about flat-footed policemen. May the saints protect us from the gifted amateur.

Trivia: Alfred Hitchcock wanted the film to look as natural as possible, with the camera at eye level with the actors. Since movie cameras were large (especially 3D cameras), Hitch had a small trench built into the soundstage floor, so that the camera lens was, roughly, at eye level.

Colin Schmit

Question: Who is in the photograph on the liquor table in the beginning?