Understanding all of Gibbs' rules in NCIS and what they mean is essential to knowing Leroy Jethro Gibbs. Mark Harmon played ...

Origins has been taking fans back to the ‘90s pre-NCIS to follow a young Leroy Jethro Gibbs, played by Austin Stowell. The ...

Rule 4 — “The best way to keep a secret: Keep it to yourself. Second best: Tell one person—if you must. There is no third ...

NCIS showrunner Don Bellisario was initially hesitant to cast Mark Harmon as Leroy Jethro Gibbs, but was eventually convinced by casting director.