This is the 300th episode of NCIS.
The words Gibbs recites (in off-screen voice over) during his sniper stake-out at the airport are (the beginning) of The Rifleman's Creed, once a core part of USMC doctrine that all recruits would learn by heart: "This is my rifle. There are many like it, but this one is mine. My rifle is my best friend. It is my life. I must master it as I must master my life. Without me, my rifle is useless. Without my rifle, I am useless."
This is the second time Mark Harmon appears in a TV show with the song "Halleujah." In the Season 3 finale of The West Wing, Harmon's Simon Donovan is killed at a New York grocery. Jeff Buckley's version of "Halleujah" follows as C.J. Cregg is told of his death. The song is sung by Taye Diggs who also played a Secret Service agent on the West Wing.
Taye Diggs and Samantha Logan play father and daughter in this episode. They would go on to play father and daughter again in the TV show All American (2018).