Arthur Hunnicutt is a guest star in this episode revolving around a dog as a suspect. He also starred in The Hunt (1962) - the only Twilight Zone episode that revolves around a man's love for his dog.
One of the fascinating legal cases referenced by Mason: 1508: The Trial of the Autun Rats.
Amos Keller (Arthur Hunnicutt) is a veteran of the Rough Riders "Battle of San Juan Hill". The actual battle took place in July of 1898, almost 10 years before Hunnicutt was born.
This is the second case where Perry cleared up questions about someone's war record. The first was The Case of the Renegade Refugee (1961).
The dog's name is Hardtack.