Robert Walker (October 13, 1918 – August 28, 1951) was a gifted American actor known for his boyish, “boy-next-door” charm, which he later masterfully subverted in one of cinema’s most iconic villainous performances. He became a popular star in the 1940s, often playing shy and sensitive young soldiers in films like See Here, Private Hargrove (1944) and starring opposite his then-wife Judy Garland in the romantic drama The Clock (1945).
He also portrayed the famous composer Jerome Kern in the all-star musical biopic Till the Clouds Roll By (1946). Robert Walker‘s career culminated with his brilliant and chilling performance as the psychopathic playboy Bruno Anthony in Alfred Hitchcock’s classic thriller Strangers on a Train (1951). Released shortly before his untimely death at the age of 32, the role immortalized him as a truly great actor and remains one of the most memorable portrayals of a villain in film history.
Source: https://en.wikipedia.org/wiki/Robert_Walker_(actor,_born_1918)