It Is Not Known. Part of the backstory of "NCIS: LA" is that as a child, Callen was a ward of the state, which never used his first name, so Callen doesn't know what it is.
More TV Trivia
Jesse Spencer. "Chicago Fire" originally premiered on October 10, 2012.
Run-D.M.C.. Pioneer hip hop group Run-D.M.C. were the first group in the genre to earn gold, platinum, and multi-platinum records and to be nominated for a Grammy Award.
Freddie Highmore. Freddie Highmore is an English actor who appeared in the film "Charlie and the Chocolate Factory".
Tommy. Tress MacNeille does Charlotte's voice on "Rugrats".
Brothers & Sisters. Calista Flockhart is married to Harrison Ford.
Cinnamon. Cinnamon, Raj's dog on "The Big Bang Theory" is a Yorkshire Terrier, and was a gift from Howard and Bernadette.