"G" Callen, played by Chris O'Donnell, is an NCIS Special Agent in charge of the Office of Special Projects Team stationed in Los Angeles.
CBS describes Callen as "a chameleon who transforms himself into whomever he needs to be to infiltrate the criminal underworld."
Sam Hanna, played by LL Cool J, is a former U.S. Navy SEAL (retired with the rank of Chief Petty Officer) working as a Senior NCIS agent in Los Angeles.
Sam Hannah is a tough character who still lives by the Navy SEAL code of conduct, and has a strong sense of honor.
Hannah speaks and reads the Arabic language, a talent he uses to assist the NCIS Los Angeles team with translation and conversation when dealing with Arabic intel. Sam also has an encyclopedic knowledge of the Qur'an
Henrietta "Hetty" Lange, played by Linda Hunt, is the Operations Manager at NCIS Los Angeles.
Known for her small stature, Hetty Lange is none the less an intimidating character.
Hetty has a very colorful past that includes relationships with past NCIS Agents as well as Hollywood Stars such as George Hamilton and Frank Sinatra.