Shadow Of A Doubt (1943) by Alfred Hitchcock

Shadow of a Doubt is a 1943 thriller directed by Alfred Hitchcock and written by Thornton Wilder, Sally Benson and Alma Reville. It stars Teresa Wright, Joseph Cotten, Macdonald Carey, Patricia Collinge, Henry Travers and Hume Cronyn.
Plot : A young woman thinks her uncle may be a serial killer.

Panic In the Streets (1950) by Elia Kazan with Richard Widmark

and starring Paul Douglas, Barbara Bel Geddes. Jack Palance, Zero Mostel
Shot exclusively on location in New Orleans, Louisiana and featuring numerous New Orleans citizens in speaking and non-speaking roles.
The film tells the story of Clinton Reed, an officer of the U.S. Public Health Service (played by Richard Widmark) and a police captain (Paul Douglas) who have only a day or two in which to prevent an epidemic of bubonic plague after Reed determines a waterfront homicide victim is an index case. Co-stars include Barbara Bel Geddes (as Reed's wife Nancy), Walter Jack Palance (in his film debut) and Zero Mostel — the latter two play associates of the victim who had prompted the investigation.

Dementia 13 (1963) Francis Coppola

Dementia 13 is a 1963 horror thriller released by American International Pictures, starring William Campbell, Patrick Magee, and Luana Anders. The film was written and directed by Francis Ford Coppola and produced by Roger Corman. Although Coppola had been involved in at least two nudie films previously, Dementia 13 served as his first mainstream, "legitimate" directorial effort.
The plot follows a scheming young woman who, after having inadvertently caused the heart attack death of her husband, attempts to have herself written into her rich mother-in-law's will. She pays a surprise visit to her late husband's family castle in Ireland, but her plans become permanently interrupted by an axe-wielding lunatic who begins to stalk and murderously hack away at members of the family.