When Mark Harmon took on the role of Special Agent Leroy Jethro Gibbs on “NCIS,” it was far from the actor’s first experience with crime dramas. Back in the 1970s, Harmon spent the first decade of his career appearing on classic TV shows revolving around law enforcement and emergency services. His second professional acting gig came in 1975 on the medical drama “Emergency!” — a series about paramedics working for the Los Angeles Fire Department. Harmon played Officer Gordon in an episode of Season 4, which was designed as a backdoor pilot for an animal control spinoff that never came to fruition.
That same year, Harmon joined an episode of “Adam-12” as Officer Gus Corbin. Harmon’s stints on crime series continued in 1975 with “Police Woman,” centering on a cop’s undercover work in Los Angeles. In a guest appearance in Season 1, Harmon portrayed the minor character Paul Donin before returning as Stanski in Season 3.
Another single-episode appearance materialized for Harmon in 1976 for NBC’s anthology show “Police Story,” where he played Officer Hazelton. His final 1970s crime drama was “240-Robert,” which followed the Los Angeles Sheriff’s Department’s search and rescue team. Harmon featured as Deputy Dwayne “Thib” Thibideaux throughout the show’s first season in 1979.
Mark Harmon’s early roles were crucial for his acting career
Mark Harmon’s transition from a UCLA college football star to a Hollywood actor was first marked by his guest roles on TV crime dramas. While trying to get his foot in the door, Harmon decided to call up “Emergency!” and “Adam-12” creator and executive producer Jack Webb — who also owned the shows’ production company Mark VII Limited. Harmon described the conversation on the podcast “The Fifth Column”: “We talked for a couple minutes, and he said, ‘Why don’t you come in and talk to me?’ And I said ‘OK,’ and I went into Universal, and I went into Mark VII.”
That phone conversation resulted in Harmon’s appearances on Webb’s crime procedurals, in addition to other 1970s shows. With more than a few credits to his name at the time, Harmon went on to have his breakout role as Dr. Robert Caldwell on the medical drama “St. Elsewhere” in 1983. He then made an even bigger name for himself on “NCIS” over 19 seasons, from 2003 to 2022, before shaking up “NCIS” with his exit.
