Who presents, I've no idea.
Meet our hero through his large Yellow Pages ad: Are you merely curious? Hire Johnny Strange of Action Incorporated!
Here he is:
Johnny gets mixed up in a murder, and has to lock horns with the local police guy, Fred Mertz:
But who committed the crime? You will not care at all, but the means by which they unmask the killer is rather novel: they have a live radio show where everyone - the cops, the witnesses, the secretary, and of course Johnny Strange - recreate pivotal moments in the plot, using scripts which contain the same dialogue we heard the first time the scene was played. And it's only an hour long.
One of those movies where someone snaps at the end, picks up a gun - radio stations back then used to have guns just sitting around, I guess - and fires it at Johnny Strange, not the cops. But he replaced the bullets with blanks! Ah hah! And then he gets the girl.
Three more to go. Three!