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 Kelly Sry Dr. Scott Long Guest Star E.R. Ruiz Carson Guest Star Terence J. Rotolo Bannon Guest Star Mike Schiff Navy Reservist John Murphy Guest Star Becky Wu June Davis Guest Star Deborah Strang Diane Warner Guest Star Erin Mathews Deputy Attorney General Mara Reeves Guest Star Stephen O'Mahoney CEO Paul Newhope Guest Star Gianni DeCenzo Owen 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 Yasmin Yilmaz Writer Marco Schnable Writer Tawnia McKiernan Director