Why did Mark Harmon leave NCIS: Naval Criminal Investigative Service in season 19? Mark Harmon has been the face of NCIS as Special Agent In Charge Leroy Jethro Gibbs since its inception in 2003, so his departure changed the show’s dynamic from that point on. While Harmon continued to serve as an Executive Producer on the series despite Gibbs’ absence from the show, his character remained out of the picture. NCIS currently holds the honor as CBS’ longest-running scripted primetime series, following the lives and adventures of the federal special agents responsible for investigating felony military crimes, preventing terrorism, and protecting secrets for the Navy and Marine Corps.
Created by Don McGill and prolific creator-producer Donald P. Bellisario, the man behind Detroit Lions baseball cap-sporting Magnum P.I. — among many others — NCIS has featured many significant cast departures over its storied 18 years, but none as impactful as Harmon’s. CBS is no stranger to replacing leading faces on their series, but NCIS somehow survived without Agent Gibbs, although he is still missed. Harmon’s departure came early in season 19, leaving CBS with plenty of time to see if the show could work without him.
To answer why did Gibbs leave NCIS in storyline terms, his last case had been long in the making. In Harmon’s penultimate episode, the team discovered the murders they thought were perpetrated by a serial killer were actually at the hands of a hired hitman (Jason Wiles). After ditching FBI Agent Alden Parker (Gary Cole), Gibbs took the hitman where he wanted to go in exchange for information. The killer blew himself up, but only after revealing he was responsible for destroying Gibbs’ boat, and not before telling Gibbs who hired him.
Gibbs traveled to Naktok, Alaska, where the investigation led him to Sonova Industries, whose pending copper mining project threatened to wreck the area. After learning Sonova’s CEO, Sonia Eberhart (Valarie Pettiford), hired the hitman to kill everyone who might disclose details of the environmental damage the mine would cause, Gibbs and the NCIS team closed in on evidence to put her away for the death of the journalist investigating it.
