Don McGill Creator Donald P. Bellisario Creator, 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, Director David McCallum Dr. Donald "Ducky" Mallard Actor Gary Cole FBI Special Agent Alden Parker Actor Zane Holtz NCIS Special Agent Dale Sawyer Guest Star Nancy Youngblut Joanna "Mama Jo" Dalton Guest Star Alex Mortensen Emmet Guest Star David Meunier Wade Cutler Guest Star Susan Diol Doris Sawyer Guest Star Aline Elasmar Annie Hankamer Guest Star Kaipo Schwab FBI Assistant Special Agent in Charge Liam McCullers Guest Star Rahvaunia Fire Captain Guest Star Andy Marques Policeman Guest Star Chas. Floyd Johnson Executive Producer Mark Horowitz Executive Producer Mark Harmon Executive Producer Frank Cardea Executive Producer George Schenck Executive Producer Steven D. Binder Executive Producer Scott Williams Executive Producer Marco Schnabel Writer