As the 20th anniversary of NCIS approaches, producers and casting agents revealed the actors who were considered for lead roles on the show. Executive producer Charles Floyd Johnson mentioned that Harrison Ford was a popular choice for the role of Gibbs but it never went further than a suggestion. Other actors considered for Gibbs were Alec Baldwin, Chris Cooper, Clive Owen, and several others. Scott Glenn was also considered for the role of Gibbs and Donald "Ducky" Mallard. Jennifer Aniston's name was also thrown into the mix at one point.