Nude Celebs: Sasha Alexander - Operating independently, the Naval Criminal Investigative Service pursues the most difficult military-related crimes. Led by taciturn Special Agent Leroy Jethro Gibbs (Mark Harmon), the crack team -- including an ex-homicide cop (Michael Weatherly), a quirky forensic specialist (Pauley Perrette), a brainy computer expert (Sean Murray) and a seasoned medical examiner (David McCallum) -- delves into cases of murder, espionage, terrorism and more.