Let the Shooters Shoot(1964)

A top-secret prototype is stolen from an American base. The man who stole it, Andersen, is murdered. The investigation is led by Jeff Gordon, who discovers in Andersen's papers a photo of a woman identified as Corinne Martin. Jeff Gordon escapes an assassination attempt on his way out of Martin's house and meets Corinne again, who denies any involvement in the robbery. Her husband, in the pay of foreign spies, is in possession of the "repeller". After several scuffles, Jeff Gordon arrests Martin and his accomplices. The prototype is returned to its base.