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 Margo Harshman Deliliah Fielding Guest Star Patricia Richardson Judy Price Fielding Guest Star Chris Agos Captain Noah Finch Guest Star Adam Hollick Christopher Blaze Guest Star Ziah Colon Pilar Rivera Guest Star Tom Yi Harold a.k.a. Delivery Man Guest Star Gilbert Glenn Brown Chief Security Officer Carson Granger 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 Yasemin Yilmaz Writer Marco Schnabel Writer Michael Zinberg Director