Born to an unnamed mother and father in Brooklyn, New York, Sam's dream from a very early age was to be a Navy SEAL.
After finishing high school, Sam presumably enlisted in the Navy and finally achieved his dream of becoming a SEAL. During his time as a SEAL, Sam served in Bosnia, Afghanistan, and Iraq and while on one mission in Bosnia, Sam along with another member of his unit, Dickerson were both captured and tortured before being buried alive.
Dickerson who was shot later succumbed to his wounds and died while Sam was eventually rescued by the other members of their team.
Sam eventually left the military with the rank of Senior Chief Petty Officer and applied to join NCIS which resulted in him being assigned to the Office of Special Projects in Los Angeles.
NCIS Season 6
Like the other members of the OSP team, Sam made his debut appearance during the Season 6/backdoor pilot episode, Legend Part 1 (episode)
Sam was also present when Callen was left gravely wounded in a drive-by shooting during Legend Part 2 (episode) and after shooting at the assassins who later fled, arrived on scene, tending to Callen while also calling for an ambulance as Sam urged Callen to stay with him.
NCIS: Los Angeles Season 1
NCIS: Los Angeles Season 2
NCIS: Los Angeles Season 3
In "Pa Make Loa", a crossover with NCIS: Los Angeles and also a part of Hawaii Five-0 Season 2, Sam traveled with Callen to Hawaii after learning of Dracul Comescu's presence in Hawaii.
NCIS: Los Angeles Season 4
NCIS: Los Angeles Season 5
NCIS: Los Angeles Season 6
- Is the only known member of OSP to be married. He was a wife, Michelle Hanna aka "Quinn" who is a former CIA agent with the two having a young daughter.
- He is very proud of his time as a SEAL, which can be analogous to NCIS Agent Leroy Jethro Gibbs's own history as a Marine.
- He and Callen have been partners for more than 5 years.
- Like Special Agent Timothy McGee, Sam is afraid of maggots as revealed in "Brimstone". He and McGee are also left-handed although he was seen writing with his right hand.
- He has Coulrophobia (fear of Clowns) and hates Snakes.
- He drives a Dodge Challenger SRT-8.