He played a "villain" in ROBIN AND THE SEVEN HOODS, but since it was a comedy, the "villians" weren't really "bad" nor menacing and Falk was superb in that movie, as was the entire cast! :-)
The original CAPE FEAR was REALLY creepy and much more terrifying than the remake! And Mitchum far more menacing and believable than Bobby de Niro who always plays every character the same way.
Robert Mitchum actually escaped from a chain gang near Savannah in his youth. It was for something minor but he was worried about making the movie which was filmed there.
RE Falk:
I remember watching “Columbo” on TV with my old man when I was a kid. Great series.
He was a convincing baddie in an Untouchables episode.