Was Lars Thorwald a Psycho?
As a Hitchcock buff, I like to spell out something "nice and neat":
Hitchcock made one movie about a psychopathic killer in each decade he worked in America:
The forties: Uncle Charlie(Joseph Cotton), Shadow of a Doubt(1943)
The fifties: Bruno Anthony (Robert Walker), Strangers on a Train (1951)
The sixties: Norman Bates(Anthony Perkins), Psycho (1960)
The seventies: Bob Rusk(Barry Foster), Frenzy (1972.)
And with each decades decline in censorship, each killer was more graphic in his crimes than those in the decade before him:
We don't even see Uncle Charlie kill anyone.
Bruno Anthony strangles Miriam in a somewhat lengthy act that ends up reflected in her fallen eyeglasses.
Norman Bates(as Mother) stabs Marion Crane and later Arbogast with a butcher knife. Much is hidden from view, but not the slash down Arbogast's face and the knife blows HEARD entering into Marion and Arbogast.
Bob Rusk first rapes, t hen strangles(with a necktie) his young female victims. We see one of these murders and the strangling is lingered on and protracted.
Four decades, four psychopaths, each worse than the one before.
But the theory is tested a bit along the way.
Were the two young, male, gay killers in Rope psychos? They killed for the thrill of it, the pleasure of it, to follow the dictates of a pompous professor who had advocated getting away with the murder of 'lesser."
And...how about Lars Thorwald in Rear Window? He comes between Bruno in 1951 and Norman in 1960 and his crime is pretty gory: