Mark Harmon NCIS Special Agent Leroy Jethro Gibbs Actor, Executive Producer Sean Murray NCIS Special Agent Timothy McGee Actor Wilmer Valderrama NCIS Special Agent Nicholas "Nick" Torres Actor Brian Dietzen Dr. Jimmy Palmer Actor Diona Reasonover Forensic Scientist Kasie Hines Actor Katrina Law NCIS Special Agent Jessica Knight Actor Rocky Carroll NCIS Director Leon Vance Actor David McCallum Dr. Donald "Ducky" Mallard Actor Gary Cole FBI Special Agent Alden Parker Actor Joshua Brockington Navy Petty Officer Third Class Felix Cross Guest Star Randy Goodwin Clark Anderson Guest Star Zeus Taylor Navy Petty Officer Third Class Kyle Seward Guest Star Kelly Stables Astrid Fellowes Guest Star Julie Pearl Cindy Anderson Guest Star Heather Olt Groundskeeper Guest Star Chas. Floyd Johnson Executive Producer Mark Horowitz Executive Producer Frank Cardea Executive Producer George Schenck Executive Producer Steven D. Binder Executive Producer Scott Williams Executive Producer Donald P. Bellisario Executive Producer Christopher J. Waild Writer Katherine Beattie Writer James Whitmore Jr. Director