The Evil Eye (1963)
Also known as The Girl Who Knew Too Much, this early giallo from Italian horror master Mario Bava (Black Sunday, Black Sabbath, Blood and Black Lace, A Bay of Blood) is distinguished by its stylish direction and clever mystery plot, as well as a cast led by the great John Saxon. He plays a doctor who comes to the aid of a pretty Roman tourist (Letítia Román) who witnesses a murder, then finds herself targeted by someone who just might be the infamous “Alphabet Killer.” Watch on Shudder.