Mark Harmon, who created the role of Gibbs on NCIS, is an executive producer on the prequel—as well as a narrator—and was part of the casting process that resulted in Stowell landing the role. But when it comes to offering advice on playing the character, he’s pretty much hands off.

Longtime NCIS star Mark Harmon's son Sean Harmon is not reprising his role as young Jethro Gibbs in the new prequel, and the decision led to “some drama brewing behind-the-scenes” of the show, a source exclusively tells In Touch.

In the role of former NCIS lead Leroy Jethro Gibbs, Mark Harmon is a tough act to follow. But it seems he found a worthy successor in NCIS: Origins star Austin Stowell.

This would be a huge responsibility for any actor.

Mark Harmon holds Jethro Gibbs close to his heart. After 18 years of playing the special agent on "NCIS," Harmon exited the show as a series regular in 2021 but remained a series regular. However, he was never far away - he cared too much to fully put it in his rearview mirror.

Mark Harmon, widely known for playing Special Agent Leroy Jethro Gibbs on the hit CBS drama "NCIS," is stepping behind the camera as the executive producer and narrator of a new spin-off prequel, "NCIS: Origins.

Austin Stowell plays Leroy Jethro Gibbs, the beloved role created by Mark Harmon on 'NCIS', on CBS' new spin-off drama When Mark Harmon first read the guest role of Naval Criminal Investigative Service special agent Leroy Jethro Gibbs on JAG in 2003,

After nearly 20 years as Special Agent Gibbs, Mark Harmon is back in the NCIS world as executive producer and narrator of the new prequel, "NCIS: Origins," which stars Austin Stowell.