At some point in time between The Girl Who Came in with the Tide (1969) and this episode, Adam Tobias (Robert Reed) had been promoted to lieutenant from sergeant.
The basement set where Mannix and Carlos Valera have their final confrontation near the end of the episode is the same basement set seen in the climax of the previous episode, "Merry Go Round for Murder".
The stadium where Valera tried to hide out was the abandoned Wrigley Field in Los Angeles. The stadium was the home of the minor league Los Angeles Angels from the 1920s until the major league Angels came into existence in the 1960s. The stadium was used in filming 30 movies and TV shows, including The Pride of the Yankees (1942), The Stratton Story (1949), Angels in the Outfield (1951), and Damn Yankees (1958), to name a few. It was also the field used for the Home Run Derby (1959) TV series. This episode of Mannix was the last time Wrigley Field was used as a movie or TV location before it was demolished in 1969.