Perry wears a cast on his arm, telling Lt. Tragg in the courtroom that an old war injury of his had flared up. Raymond Burr broke his arm in real life, and would wear the cast for several episodes.
Scenes set at "Correli's Bar" were shot on location at the commissary of Desilu Studios - as indicated by the 3-D bust of Desilu co-founder Lucille Ball mounted on the wall behind Mason in the final scene.
In one scene, Lt. Tragg says he has been a police officer for 30 years. This episode was broadcast in 1960, so Tragg began his law enforcement career in 1930 or thereabouts.