Scott Riley was a Private in the United States Marine Corps who was responsible for the death of Marine Lance Corporal Edward Mackaye.
Riley was also a member of "Enhancing Law Enforcement," or ELE for short, a dangerous militia group dedicated to stopping illegals from entering America by crossing the border.
With Riley's help, the group stole a set of Dragon anti-tank missiles from the armory at Camp Pendleton, prompting NCIS Special Agent Mike Renko and eventually the Office of Special Projects to start an investigation.
Reilly's motive would be to sneak up on his victims and then garrote them, essentially strangling them to death.
Riley is highly devoted to his cause and, according to Nate Getz, will never betray his cause because he is afraid of someone or something. Riley is also merciless and expresses no remorse for his actions, hinting that he is probably a sociopath or a psychopath.
- Brian Letscher previously appeared in the main NCIS series in the Season 6 episode, Road Kill (episode).