In honor of the show's 20th anniversary, the creators of 'NCIS' revealed the names they considered for the series' stars. The show started as a two-episode backdoor pilot on JAG before becoming its own spinoff. Initially, the spinoff was supposed to be split like Law & Order, focusing on an investigation and legal matters. However, CBS president Les Moonves decided to make it all about the investigation.

For the role of Special Agent Gibbs, Harrison Ford was considered, but the role eventually went to Mark Harmon. Other names considered for various roles included Alec Baldwin, Chris Cooper, Clive Owen, and Patrick Swayze. Jennifer Aniston's name was even floated for a role, and Michael Weatherly was unable to take the part of Tony Di Nozzo initially due to filming commitments.