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 Gary Cole FBI Special Agent Alden Parker Actor Nancy Travis Harriet Parker Guest Star Steven D. Binder Executive Producer David J. North Executive Producer Chas. Floyd Johnson Executive Producer Mark Harmon Executive Producer Scott Williams Executive Producer Christopher J. Waild Executive Producer Mark R. Schilz Executive Producer Diana Valentine Director