The character of Detective Robert Goren (Vincent D'Onofrio) is based on Sherlock Holmes, but instead of relying upon physical evidence like Holmes, D'Onofrio's character focuses on psychology to identify the perpetrators, whom he often draws into confessing or yielding condemning evidence. The character of Nicole Wallace (Olivia d'Abo) is a direct attempt to play on the part of Sherlock Holmes' female antagonist Irene Adler, also known as "The Woman". Wallace is employed as a "Professor of Literature" during her first appearance, which could be a parallel to Holmes' nemesis Professor Moriarty.
At the end of the fourth season, Jamey Sheridan suffered Bell's palsy, a facial paralysis that affected one half of his face. In the fifth season, his character, Captain James Deakins, carried an eye patch over his left eye, to hide the signs of the paralysis.
The following statement appears at the beginning of each episode: "In New York City's war on crime, the worst criminal offenders are pursued by the detectives of the Major Case Squad. These are their stories." This is the only Law & Order series where the opening statement does not begin with the words "In the criminal justice system..."
The show's format was partially inspired by Columbo (1971), starring Peter Falk. Both started out with the crime being seen from the criminal's point of view, and with them confident that they can get away with it. However, they then get outsmarted by a brilliant detective. The shows differ, in that Columbo (1971) usually showed the full crime in the beginning, while in this show, the viewer is only shown enough to be a few steps ahead of the detectives in knowing what happened. Goren and Columbo also have very different styles in analyzing the crime, and the suspects.
Vincent D'Onofrio and Chris Noth have both played the role of Phil Romano in That Championship Season, the former in the 1999 film, and the latter in the 2011 Broadway revival. In an earlier film version, the part was played by Paul Sorvino, Noth's co-star on the original Law & Order (1990).
The second spin-off of Law & Order. Law & Order (1990), Law & Order: Special Victims Unit (1999), Law & Order: Criminal Intent (2001), Law & Order: Trial by Jury (2005), Law & Order: UK (2009), Law & Order: LA (2010), and Law & Order: True Crime (2017).
While Chris Noth and Leslie Hendrix reprised their roles from "Law and Order" (1990), other actors appeared on both shows as different characters. This includes Courtney B. Vance, Eric Bogosian, and Julianne Nicholson.
Both Jeff Goldblum and Vincent D'Onofrio have both appeared in the Jurassic Park film franchise. Goldblum was in both of the first two Jurassic Park (1993) and The Lost World: Jurassic Park (1997). And, D'Onofrio was the villain in the fourth installment, Jurassic World (2015).