The Big Oskar (1958)
I just finished watching this one on DVD. It's really a strange episode with only two other characters involved, a man who seems to be reporting the finding of stolen items, and a flighty woman crime victim.
I noticed that Joe is Lieutenant Friday and Frank is Sergeant Smith in this one. It's the first episode where I have noticed that the two of them have both been promoted. In the episode I had watched just before this one, The Big War, Frank was talking about studying for the sergeants exam.