Cecil Kellaway (Darrel Metcalf) was one of Hollywood's busiest and most reliable character actors, with nearly 150 credits in his IMDB filmography. He had roles in such memorable films as Hush...Hush, Sweet Charlotte (1964), the James Stewart version of Harvey (1950) and The Postman Always Rings Twice (1946), in which he was the husband Lana Turner and John Garfield plot to murder. He was twice Oscar nominated as Best Supporting Actor, for his portrayal of a Leprechaun in The Luck of the Irish (1948) and for his performance as Spencer Tracy's clergyman in Guess Who's Coming to Dinner (1967).
Director Gerd Oswald tried to create action by zooming in on characters at certain moments, something not often done in the series.
When Perry called Frederick Rollins, Rollins conversed through the phone with the mouthpiece of the receiver to his mouth but the earpiece on his chest. That's because he had an old-fashioned hearing aid with the earpiece wired to a large speaker that he kept in his shirt pocket. If he had put the receiver earpiece to his ear, he could not have heard what Perry said. He was able to hear only by putting the receiver to the speaker in his shirt pocket.
Guest cast member Gage Clarke and cast regular William Hopper both appeared in the film The Bad Seed (1956).
In an early scene with Della, Perry addresses her as "Miss Street"; however, this may be because she is on the phone when he walks in.