Stories from the set

Leroy Jethro Gibbs (Mark Harmon) as a young man is played by Sean Harmon, the son of actor Mark Harmon.

Pauley Perrette, who plays Abby, actually studied forensic science in college, then moved to New York, where she went into acting. According to the show's producers, Abby's character traits and personality are in fact the character traits and personality of Perrette herself, who was simply playing herself.

During the opening credits of the first couple of seasons, an aircraft carrier is shown passing under the famous Golden Gate Bridge in San Francisco. This is footage from Peter Hyams' action film "The Presidio" (1988), in which Mark Harmon, as a San Francisco police inspector, investigates a murder on the grounds of a military base.