Being Falsely Accused
Dial M for Murder does not really break any thematic ground for Hitchcock so much as it deepens the resonance of several recurring themes that existed up to the film’s release and would continue in films made afterward. Nearly every Hitchcock murder mystery has someone having to deal with a world turned upside down by being false accused with no easy way to prove your innocence. The big difference here is that this time the falsely accused murderer is a woman.
The Secret Life of Womens' Purses
In the world of Hitchcock’s women, what’s inside their handbags and purses should never be open for intrusion by their male partners. Purses represent everything from independence to secret sexual desires to open sexual infidelities. This level of metaphor reaches its apex in Marnie, but Dial M for Murder makes a strong case for the number two position. The purse and whether there was a key inside and who was responsible for taking that key all are vital plot elements, but thematically speaking, the husband in the film crosses a line that is guaranteed to come back on his big time the moment he dares to break that unwritten law about a woman’s purse being the only property she may have any right to.
The Elusive Perfect Murder
Not all murders that occur in a Hitchcock are designed to be perfect. Most, in fact, occur without much planning beforehand. Dial M for Murder belongs to that class of Hitchcock films like Strangers on a Train and Rope in which the murder calculated a strategy for getting away with it that might well have worked had they only been able to control everything else. Most of the characters who inhabit this mini-genre of Hitchcock cinema are wealthier, better educated, enjoy more privilege that most and are far more narcissistically sure of their superiority over mere policemen than those other Hitchcockian murderers. As with the heroes of Greek tragedy, it is precisely that undeserved self-confidence that usually keeps their murders from being perfect rather than any actual display of superiority in the intelligence of the police.