Dirk Rambo was killed in an auto accident 11 days before this episode aired.
The red Cadillac convertible with the black ragtop, which appeared out in front of the Hubbert home in this particular Dragnet episode, was a 1953 Cadillac Eldorado convertible.
In this story Virginia Vincent plays a woman---Edna---who tells the cop she is 29 years old. The actress was 3 months shy of 49---and even looked a few years older---at the time of its filming. This was perhaps a character's white lie, since Friday gives her a strange look when she says she's 29.
This episode aired a week after "The Interrogation," which involved a young policeman, played by Kent McCord, accused of robbing a liquor store because the actual thief closely resembled him. Ron Russell, who plays Larry Hubbert, closely resembles Kent McCord.