The program ran for 139 episodes over six seasons and there was one belated television movie. In season 5, Estrada was occasionally replaced by Bruce Jenner (Steve McLeish) due to a contract dispute. Prior to season 6, Wilcox fell out with Estrada and left to be replaced by Tom Reilly (Bobby Nelson) who was in turn replaced in later episodes by Bruce Penhall (Bruce Nelson) following a falling out between Estrada and Reilly. Due to falling ratings through seasons 5 and 6 the show was cancelled in 1983.
Other regular actors were Michael Dorn (Officer Turner), Brodie Greer (Officer Baricza), Paul Linke (Grossman), Robert Pine (Sergeant Getraer), Randi Oakes (Officer Bonnie Clark), and Lou Wagner (Harlan).