The United States Navy has exactly one military facility in the entire state of Louisiana. So needless to say, the actual NCIS Resident Agent staff in New Orleans is small. It consists of two agents and a small support staff. NCISRA New Orleans reports to the NCIS regional office in Chicago.
The character of Chris LaSalle (like Lucas Black, the actor who plays him) grew up in Alabama. Unlike Black, LaSalle attended the University of Alabama and played the school mascot, Big Al, while a student there; dialogue in one episode even implied that LaSalle has a tattoo of Big Al on his rear.
The theme song "Boom Boom" is by John Lee Hooker, performed with Big Head Todd and The Monsters. Hooker is from Detroit. The band is from Colorado. Nobody from New Orleans. NCIS: New Orleans' Executive Producer Gary Glasberg attempts to explain - "Boom Boom" had "the vibe I was looking for."
In the first season opening credits, Scott Bakula appears briefly covered by a blue glow. This is a nod to his portrayal of Dr. Samuel Beckett in Quantum Leap (1989). Dr. Beckett glowed in such a manner just as he was about to "leap" at the end of each "Quantum Leap" episode.
Duane Pride and some of the other agents wear handguns in small of the back holsters. Most law enforcement officers avoid this type of holster because of the risk in a fight of falling and having it driven against the spine, which causes enormous pain and can cause paralysis.