Navy NCIS: Naval Criminal Investigative Service is the official series title during the first season. Mark Harmon tops the cast as the rule-bending, intensely private Leroy Jethro Gibbs, the head of an elite NCI team specializing in solving baffling crimes related to US Navy personnel. Gibbs' cohorts include tough, outspoken Caitlin "Kate" Todd (Shana Alexander), former Baltimore homicide detective (and flagrant womanizer) Anthony "Tony" DiNozzo (Michael Weatherly), caffeine-addicted, goth-girl technogeek Abby Sciuto (Pauley Perrette), and all-knowing, long-winded chief lab technician Donald "Ducky" Mallard (David McCallum). The two-part pilot episode was filmed for the military-legal series JAG, and was not shown until several weeks after NCIS premiered with its debut episode "Yankee White." Its plot involving a mysterious death during a flight of Air Force One, "Yankee White" also introduces several recurring characters: Alan Dale as NCIS director Tom Morrow, Joe Spano as FBI agent Fornell and Pancho Demmings as Ducky's assistant Gerald Jackson.