Long running series 'NCIS' spawns another spin-off with 'NCIS: Origins,' which delves into Gibbs' early years.

Warning: SPOILERS for the NCIS: Origins two-part premiere “Enter Sandman” are ahead!

NCIS: Origins showrunners reveal if Mark Harmon will appear in future episodes following his cameo in the premiere.

NCIS' star Mark Harmon has been married to his wife, 'Mork & Mindy' actress Pam Dawber, since 1987. Read all the details on ...

Mark Harmon's colourful life and career explored. From his defining role as Leroy Jethro Gibbs in NCIS to his sweet love ...

For over a decade Mark Harmon portrayed the role of Leroy Jethro Gibbs in the hit TV series NCIS. As producers and ...

NCIS: ORIGINS premiered this week, and in honor of the show, stars Mark Harmon and Austin Stowell spoke to PEOPLE about their ...

and all of a sudden, you're presented with a badge with your name on it," he first said of working on the iconic Paramount lot. MORE: NCIS alum Mark Harmon marks extra special holiday weekend with ...

Related: NCIS alum Pauley Perrette says she'd never return to acting, 5 years after allegations against costar Mark Harmon "'You always have all of me,'" the actor remembered telling North and ...

Harmon confirmed that many actors tried out for ... tuned into the Origins premiere in its first week, CBS would cancel all of its other programming and throw all of its money at Stowell.

After all, these were high stakes seeking the coveted role of young Leroy Jethro Gibbs, famously embodied by Mark Harmon for 19 TV glory-filled seasons. Gibbs is the guy in the "NCIS" universe ...

Fans of "NCIS" will be transported back to where it all began in the new prequel series. New episodes will be available on ...