who plays agent callen on ncis los angeles
G. Callen G. Callen (born: Grisha Alekandrovich Nikolaev) is a fictional character in the show NCIS: Los Angeles portrayed by Chris O'Donnell. He is an NCIS Special Agent in Charge, and the senior agent assigned to the Office of Special Projects. O'Donnell made his first appearance during NCIS' sixth season episode "Legend (Part 1)".
Eric Christian Olsen Olsen portrays Detective Marty Deeks on the CBS show NCIS: Los Angeles. His character appeared in two episodes of season one before joining the cast as a series regular in the second season.[8]