Donald P. Bellisario Creator, Executive Producer Don McGill Creator 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 Teri Polo Vivian Kolchak Guest Star Erik Passoja FBI Deputy Director Wayne Sweeney Guest Star Jessica Gardner Olivia Kahn Guest Star Francis X. McCarthy Roman Parker Guest Star Jene Bush Frank Ressler AKA Birdwatcher 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 David J. North Executive Producer Christopher J. Waild Writer Terrence O'Hara Director