Detective stories were popular on radio: the suspense, the puzzle (pitting your wits against the detective), the exposition, all made for engaging radio drama. But crime stories in which the law always triumphed and evil was always exposed and punished provided audiences with a recurrent sense of reassurance in troubled times (the Depression, the wars, the Cold War). During the 1930s and early 1940s the emphasis was on realistic police and law enforcement dramas, catering to the need to allay the anxiety of the public about the threat to civil society from gangsters and racketeers. Alongside the realistic docudramas were a series of detective stories derived from pulp fiction. The leading pulp publishers were Street and Smith and they had a weekly mystery show on radio in which their thriller stories were dramatized. Alongside the films, radio played its part in dramatizing the Charlie Chan stories.