It Takes A Thief (1960)

aka: The Challenge

Billie (Jayne Mansfield) and Kristy (Carl Möhner) lead a gang of armed robbers who steal from banks, armored cars and the like. When Billie’s lover, Jim (Anthony Quayle), gets caught by the police after stashing a large amount of money, they wait for him to get out of jail. He does and has to deal with both the police and his ex-gang as they both need him to get what they want. Complicated ensue when Kristy kidnaps Jim’s son and threatens to kill him if Jim doesn’t come up with the buried loot.