Homicide (1964) : 9x40

A middle aged invalid is discovered dead in her bedroom and Homicide detectives find themselves on the trail of a demented killer. Widow Mrs. Anstey befriends a mild mannered man, Albert Fisher, in a cemetery, who is actually the embittered killer whose motives are complicated by his belief that his actions are mercy killings. Fisher's daughter Marjorie gradually realizes the situation and begins to fear for her own life.