This is an overview of regular and recurring characters on the TV series NCIS: Los Angeles. Overview Main Cast Recurring Cast Main characters G. Callen G. Callen (portrayed by Chris O'Donnell) is a Special Agent in Charge assigned to the NCIS Office of Special Projects. Nate "Doc" Getz Dr. Nate Getz (portrayed by Peter Cambor) is an operational psychologist working with NCIS, stationed in Los Angeles, introduced in the series' backdoor pilot, the NCIS episode "Legend". Nate holds both a master's degree and Ph.D. in psychology. He observes surveillance tapes and watches/handles interrogations in order to make a psychological profile. He is also responsible for performing periodic psychological evaluations of the NCIS OSP personnel and to provide ongoing monitoring of their mental health. He is afraid of disobeying orders from Hetty Lange and finds her scary. The team often fails to get his humor, for example, in "The Only Easy Day" when he states: "What has the world come to when drug dealers aren't even safe within the comfort of their own fortified homes?" He also knows how to play banjo and harmonica, and enjoys listening to jazz music. In the episode "Callen, G" he claims he was abducted by aliens as a child. In the episode "Chinatown", Nate expresses his interest in becoming a field agent which is highly discouraged by the team members because of his inept field skills. He asks Hetty if she can think of any operational psychologist who has become a field agent; however, when she shares that the only known such person died on his second week of field work, Nate gets a little iffy about his choice. Despite this, Nate has received training in both fieldcraft and hand-to-hand combat, as demonstrated on several occasions in the episodes "Lockup" and "Harm's Way". Nate and recurring character Rose Shwartz share an unconsummated mutual attraction. This has not been explored further as Peter Cambor is no longer a member of the main cast. Cambor's departure as a main cast member coincides with Nate's reassignment to the Middle East to investigate an Islamic militant group based in Yemen. With the conclusion of that mission in the episode "Harm's Way", Nate's current assignment is undisclosed, although it is known that he is remaining in the Middle East for the time being. Nate returned to Los Angeles in "Patriot Acts" where he helped the team locate a domestic terrorist