Schizo (1976)

Samantha and Alan are getting married, but William Haskins isn't pleased. He grabs a train south to London and starts shadowing Samantha as she adjusts to married life. Haskins' attempts to frighten her drive her to desperation, but she's having trouble convincing anyone that she's being stalked. Even her psychiatrist dismisses her concerns as part of her neurosis. As bodies begin turning up, Samantha's story becomes more believable, and her dark secret from the past reveals itself.