NCIS is an American dramatic police procedural television series, revolving around a fictional team of special agents from the Naval Criminal Investigative Service, which investigates crimes involving the U.S. Navy and Marine Corps. The series was created by Donald P. Bellisario and Don McGill as a backdoor pilot with the season eight episodes "Ice Queen" and "Meltdown" of JAG. The series premiered on September 23, 2003 featuring an ensemble cast which has included Mark Harmon, Sasha Alexander, Michael Weatherly, Cote de Pablo, Pauley Perrette, Sean Murray, Lauren Holly, Emily Wickersham, Brian Dietzen, Wilmer Valderrama, Jennifer Esposito, with Rocky Carroll, and David McCallum. This is a list of NCIS main and recurring characters.