In 1984, she appeared in Sergio Leone's gangster epic Once Upon a Time in America, playing a jeweler's secretary, who is in on a plan to steal a shipment of diamonds. During the robbery, her character goads Robert De Niro's character, David "Noodles" Aaronson, into "raping" her with her complicity. She later meets up with the gang from the robbery, and becomes the moll of James Woods' character Max Bercovicz. Disturbed by what she sees as Max's delusional, even suicidal, ambitions, she convinces Noodles to betray Max to the police. The performance earned Weld a BAFTA nomination for Best Supporting Actress of 1984.
