The Fan (1981)
The final act is murder.
Lauren Bacall is glamorous stage and screen star Sally Ross, who has decided to take a role in a new Broadway musical. Meanwhile, an obsessed young fan, Douglas Breen, who has tenuous grip on reality, has been writing obsessive fan letters to her. Sally's secretary, Belle, disregards the letters, deeming them not worthy of Sally's time. But as Douglas realizes that he is being ignored, he decides to take whatever steps are necessary to eliminate the people who stand between him and his favorite star.