Monty is the dog of Marty Deeks, the LAPD officer who is also the liaison between the NCIS Office of Special Projects and the Los Angeles Police Departement, and a returning character in "NCIS: Los Angeles".
Monty is a loyal canine companion, who sometimes goes undercover with Deeks. Monty's special talent is that he can smell out bombs. Although he may not be on active duty, Monty has already saved the team by sniffing out a hidden plastique bomb. Little is known of his life before joining Deeks, although Deeks says that he was a rescue dog, suggesting he spent time in an animal shelter.
Monty appears to be a mutt rather than a pedigree dog.