Early in their careers, Miguel Ferrer and his brother Rafael Ferrer were cast in guest roles on this series. Their episodes were to be filmed close together, so they decided to take a vacation on location. They invited their father, José Ferrer, and their cousin, George Clooney. He had tried and failed to make it as a professional athlete, and was trying to figure out his next move. During this vacation, Miguel encouraged him to take up acting.
The show was canceled at the end of the 1982-83 season, due to low ratings. In response, viewers wrote to CBS, protesting the cancellation. This effort, combined with the show's increasing ratings during the summer reruns, prompted the network to reverse the decision. Although the cast members had just been released from their contracts, they were soon brought back to work on the show. The series was reinstated in March of 1984, and ran until 1988.
In the TV movie that inspired the series, Christine Cagney was played by Loretta Swit. Swit was unable to continue playing Cagney in the series due to her contract with M*A*S*H (1972). Meg Foster took over the role of Christine Cagney. After the first season, Sharon Gless eventually won the role and played Cagney for six years. A CBS spokesperson was quoted at the time as saying the reason for replacing Foster with Gless was the audience had trouble telling "the two leads apart". But the real reason CBS wanted to replace Foster is because they felt that her portrayal made Cagney appear to be a lesbian. When the show was revived from cancellation after the first season, CBS demanded that Barney Rosenzweig replace Foster.
The screenplay for the pilot was originally written in the 1970s for a featured film that never materialized. After the success of Charlie's Angels (1976), producer Barney Rosenzweig shopped an edited version of the screenplay as a possible TV series. It took many years for the script to be produced because the networks felt that there was no audience for a realistic show about female detectives.