"NCIS" is a spin-off of "JAG," which in turn spun off two more series "NCIS: Los Angeles" and "NCIS: New Orleans."
JAG is an adventure drama about an elite wing of officers trained as lawyers who investigate, prosecute and defend those accused of crimes in the military. Navy Cmdr. Harmon "Harm" Rabb, an ace pilot turned lawyer, and Marine Lt. Col. Sarah "Mac" MacKenzie, a beautiful by-the-book officer, are colleagues who hold the same high standards but find themselves clashing when they choose different routes to get to the same place. The unmistakable chemistry between them must be held at bay for professional reasons as they traverse the globe together with a single mission: to search for and discover the truth. Helping them with their mission is Navy Lt. Cmdr. Bud Roberts, a lawyer who proved his grit and determination when, after losing a leg in a land mine field while on a mission, fought back and became even better at his job.
Explore the inner workings of the government agency that investigates all crimes involving Navy and Marine Corps personnel, regardless of rank or position. Leading this team is NCIS Special Agent Leroy Jethro Gibbs, a skilled investigator and interrogator who is smart, tough and willing to bend the rules to get the job done.
NCIS: Los Angeles is a drama about the high stakes world of undercover surveillance at the Office of Special Projects (OSP), a division of NCIS that is charged with apprehending dangerous and elusive criminals that pose a threat to the nation's security, specifically Naval and Marine assets and personnel.
The NCIS's New Orleans field office investigates criminal cases affecting military personnel in The Big Easy, a city known for its music, entertainment and decadence. Leading the team is Special Agent Dwayne 'King' Pride, a native of New Orleans who is driven by his need to do what is right. Working with him is Special Agent Christopher LaSalle, who plays hard but works harder; and Special Agent Meredith 'Merri' Brody, a charismatic and tough interrogator who transferred from the Great Lakes office in search of a fresh start. Supporting them is coroner, Dr. Loretta Wade, who is as eccentric as she is smart. This colorful city that harbors a dark side is a magnet for service personnel on leave, and when overindulgence is followed by trouble, Pride's team is at its best.