Two elderly women have been killed by a hit-and-run driver--and the lack of skid marks at the death scene indicates that the driver didn't even bother to slow down after striking his victims. Investigating, Friday (Jack Webb) and Smith (Ben Alexander) learn that the driver was a young blonde man, and that the vehicle was a late-1930s model. A visit to a helpful used-car dealer may provide a vital clue. When this episode was adapted for television from the Dragnet radio broadcast of June 21, 1951, the character of Joe Friday's mother was written out--and Joe's erstwhile girlfriend Ann Baker (Dorothy Abbott) was written in! ~ Hal Erickson, Rovi