John McIntire (Lieutenant Dan Muldoon) left the series midway through the first season because, reportedly, he was tired of the New York City location filming grind, and wanted to return to his house in California. An earlier trivia statement claimed that McIntire couldn't stand working with James Franciscus. However, McIntire worked with Franciscus on the television movie pilot, and one episode of Longstreet (1971).
Ladies and gentlemen, you are about to see "The Naked City." I'm Bert Leonard, the producer. This story was not photographed in a studio. Quite the contrary. The actors played out their roles in the streets and the buildings of New York itself.
On some season 2 (1960-61) episodes, the main guest star was listed before the show's regulars in the opening credits.