The Transfer of Guilt
Early Hitchcock
The Transfer of Guilt
Both Sylvia in Sabotage and Alice in Blackmail have, by the end of the film, effectively got away with murder. Rohmer-Chabrol, in Hitchcock: the first forty-four films, talk of the 'explosion providentielle', Sylvia's guilt has been transferred to the bomb-maker.
Hitchcock treats guilt as highly contagious in his films. The previously honest detective Ted becomes a criminal by his involvement with the guilty woman. The same is true of Frank in Blackmail. Also in Blackmail, both the bomb-maker and the blackmailer die for someone else's crimes. Parallel editing shows the blackmailer's flight from police intercut with close-ups of the true murderess in remorse. The crimes are punished but it's not necessarily the correct person who receives the punishment.