The latest on NCIS, the popular CBS drama series. Originally a spin-off from the show JAGNCIS premiered in 2003 and has become consistently one of the most watched series on TV every year since. Starring Mark Harmon, the series is based on the special agents that make up the Naval Criminal Investigative Service. The popularity of the show has inspired two spin-off series, NCIS: Los Angeles and NCIS: New OrleansNCIS is one of the longest running prime series in TV history, alongside shows like Law & Order: SVU and The Simpsons