NCIS: Los Angeles is an American action television series combining elements of the military drama and police procedural genres, which premiered on CBS on September 22, 2009.

Other stars in other seasons included Eric Christian Olsen, Renée Felice Smith, Miguel Ferrer, Nia Long,[3][4][5] Medalion Rahimi, Caleb Castille, and Gerald McRaney.

NCIS: Los Angeles received generally mixed-to-positive reviews from critics, but became a solid ratings hit for CBS at the time of its premiere.

At the start of the series, Sam, Callen, and Hetty are supported by Special Agent Kensi Blye (Daniela Ruah), a hand-to-hand combat specialist, trained sniper and forensic whiz, rookie agent Dominic Vail (Adam Jamal Craig), Operational Psychologist Nate Getz (Peter Cambor) and Technical Operator Eric Beale (Barrett Foa).

He holds this position until departmental reforms in season 12 end up terminating it, after which he completes FLETC training and officially joins NCIS as an Investigator.

Also joining the team in season 2 is Intelligence Analyst Nell Jones (Renee Felice Smith), a brilliant agent whom Hetty hopes to have take her place eventually, and who forms a close relationship with Beale.

With Hetty leaving to do damage control from a prior mission, Admiral Hollace Kilbride (Gerald McRaney), who has assisted the OSP in multiple cases, is assigned in her place as Director of Special Operations in season 13.

The series ends with Callen marrying long-time love Anna Kolcheck, and him and Sam taking a "side project" mission to find and rescue Hetty with a new team, which includes old teammates Nate and Nell.

Later, Callen and Sam must return to Los Angeles to stop a possible smallpox outbreak from becoming a reality with Danny Williams and Chin Ho Kelly from Hawaii coming along to help.

After taking over show runner duties previously held by Donald P. Bellisario on NCIS, he used the potential of a spin-off to bring his story to fruition.

Macy was portrayed by Louise Lombard in the backdoor pilot, but she was not featured in the actual spin-off, and Brennan was able to produce the show as he originally envisioned it.

However, discussions continued between CBS and Bellisario, and in January 2013 the dispute was settled outside of court a week before it was set to go to trial; the terms of the agreement were not disclosed but were described as being amicable.

According to Mary McNamara of the Los Angeles Times, "The crime is intriguing and multifaceted, its resolution requiring a nice balance of street smarts and lots of gunfire.

But as with the original 'NCIS', the emphasis is on the characters of the team... Los Angeles, meanwhile, looks fabulous, a pleasing mixture of noir and gridlock, and there's an air of stability that's comforting in these uncertain times.

"[31] The New York Daily News reviewer, David Hinckley, was more critical of the show saying that although "It all adds up to an hour of decent entertainment, and there's room for enough character development to give 'NCIS: Los Angeles' a personality of its own, ... a premiere episode shouldn't feel even a little like something we've already seen.

It's a procedural that follows strictly the established procedure, but it has likable characters, dislikable bad guys and the occasional flabbergasting shot of L.A."[33] Robert Bianco of USA Today summarized it as a "serviceable hour that takes the NCIS formula—a light tone and a lot of banter wrapped around a fairly rudimentary investigatory plot—and transfers it to a special, undercover NCIS division in Los Angeles.

"[35] IGN stated that although "NCIS: Los Angeles doesn't exactly reinvent the police procedural... it's another above-average entry, aided by the fact that the people behind the show know what they're doing" and ultimately gave the episode a 7.7/10.