One of the themes found in the films of Alfred Hitchcock is that of the transference of guilt, a theme started in the British period and carried over into the cross-over period and beyond. This involved much more than simply the fact that the protagonist would be falsely accused of a crime he did not commit, though in the earlier films especially this would be closer to the way the issue was presented. Later, however, the protagonist would also be expiating some guilt of his own through this false accusation, and a key film in the development of this sense of guilt and transference is Shadow of a Doubt from 1943. William Rothman (1982) calls this Hitchcock's first American film to be the equal of his British work and says that it "gives form to all he learned in Hollywood as it declares continuity with the whole body of his earlier work" (178).
The transference of guilt is indirect rather than direct, implied rather than overt. Uncle Charlie's guilt is transferred to his niece because she is the only one who knows about it, and this creates a dilemma for her in her family and her community. Her true guilt is entirely in not telling anyone about what she has learned of her Uncle Charlie. Her guilt is one of omission rather than commission, but it nearly leads to her death. In the final moments, expiation for this sin will be borne by one or the other Charlie.
The fact that the names are the same is a Hitchcock device that links two characters and that allows for the audience to see easily that guilt is being transferred from one namesake to the other. Hitchcock uses other devices at different times - in The Wrong Man it is a physical similarity that is at fault, while in Vertigo it is a complex plot and the psychopathology of both the protagonist and the two women he thinks are different people. In North by Northwest the transference is completely accidental when Thornhill calls for a bellboy. In Strangers on a Tra...