This was the final time that Ray Collins was listed in the opening credits. He would die from the emphysema that forced him to leave the show the previous season.
Lookalike character stories were a popular trend at the time. Examples include The Parent Trap (1961), The Prince and the Pauper (1962), and TV sitcom The Patty Duke Show (1963).
In a break from the usual routine, a witness on the stand assists Mason in revealing the murderer's identity.
Early in the show, Dorrie Ambler tells Perry and Della that she is 5' 4" tall, and her driver's license confirms this. In real life, actress Mary Mitchel was indeed 5' 4" tall.