The show will air its 1000th episode in the franchise on Monday night.
The show aired its first episode on Sept. 23, 2003.
The actor just wrapped up a 14-season run on 'NCIS: LA' with Sunday's series finale.
'NCIS: LA' series finale airs May 21 at 9 p.m. ET/PT on CBS, followed by 'A Salute to NCIS: LA,' an Entertainment Tonight special.
'A Salute to NCIS: Los Angeles,' hosted by Kevin Frazier, will air Sunday at 10 p.m. ET/PT following the final episode of the series.
The final episode airs Sunday, followed by a retrospective special.
The series finale airs Sunday, May 21 at 9 p.m. ET/PT on CBS.
LL Cool J, Chris O'Donnell, Eric Christian Olsen, Daniela Ruah and more talk to ET about wrapping up the show after 14 seasons.
ET spotlights LL Cool J's legacy and career, from his music hits and acting roles.
The CBS procedural will air its series finale in May.
The rapper-actor stepped out on the GRAMMYs carpet Sunday to take part in the star-studded Hip-Hop 50 tribute.
LL Cool J chats with ET at the 65th GRAMMY Awards, airing on CBS.
Daniela Ruah and Boomer Esiason chat with ET ahead of 'Super Bowl Greatest Commercials: Battle of the Decades,' airing Feb. 8 on CBS.
The actress opened up to ET this week while promoting her upcoming 'Super Bowl Greatest Commercials' special.