15 surprising facts you might not know about the 'Law & Order' franchise

When the show premiered, most dramas were shooting in Los Angeles and using establishing shots of New York. "Law & Order," however, decided to shoot entirely in New York City to really get a feel for the city streets.

"You get glimpses of the buildings through windows," Joseph Stern, an executive producer on the show at the time, told The New York Times in 1992. "And you know you can't be anyplace else. And you're always hearing the city. The traffic. The voices. The cops have a New York accent."

The majority of the franchise still shoots in New York City 3o years later.

Any "Law & Order" fan knows the dun-dun sound at the end of the intro. But they may not know that the sound is actually supposed to represent the sound of a jail cell closing.

"I wanted to add something that's very distinctive but not a literal sound. What I tried to do was jar a little bit," Mike Post, the composer of the sound, told Entertainment Weekly in 1993.

To do so, Post blended several noises together, including the sound of 500 Japanese men stomping at a Kabuki event.

"They did this whole big stamp," Post said. "Somebody went out and sampled that."

Chris Noth, for example, played Detective Mike Logan in the original series for five seasons. He left the franchise until he reprised his role in 2005 on "Law & Order: Criminal Intent."

Christopher Meloni left "Law & Order" SVU after 12 years playing Detective Elliot Stabler. This year, he reprised the role in a new series called "Law & Order: Organized Crime."

Richard Belzer introduced Detective John Munch on NBC's "Homicide: Life on the Street" in 1993. When the show ended in 1999, Belzer brought the role to "Law & Order: SVU."

While being a series regular on "SVU," Belzer took Munch outside of "Law & Order" and made appearances on "The Wire," "30 Rock," "X-Files," and "Arrested Development."

In 2013, Belzer left "SVU."

S. Epatha Merkerson is known for her role as Lieutenant Anita Van Buren on "Law & Order," but the actress first played a mother whose son is shot in season one in 1991. She returned in 1993 to take on the role of Van Buren.

Likewise, Peter Scanavino is known in the "SVU" universe as Detective Dominick Carisi, but he also played a janitor earlier in the series. Diane Neal played Assistant District Attorney Casey Novak, but she first appeared in the series as an accused murderer.

In 2017, Ice-T broke the record for the longest-running Black character on TV with his role of Detective Tutuola for 18 seasons on "Law & Order: SVU."

The person who held the title before him was S. Epatha Merkerson, who played Lieutenant Anita Van Buren on the original "Law & Order" for 17 years.

After 22 seasons, Olivia Benson — played by Mariska Hargitay — is now considered the longest-running character in a primetime live-action series, according to Deadline. Plus, "SVU" is the longest-running prime-time live-action series.

To fully immerse himself in the role of detective, Noth used to shadow real New York detectives. In 1992, he told the New York Times about a time he tagged along on a missing person investigation. When interviewing the roommate of the missing person, he recalled the smell of the apartment.

"The detective smelled death," Noth told the publication. The body of the missing person was later found in the apartment.

Likewise, Hargitay has become a trained rape crisis counselor, and she started "the Joyful Heart Foundation in 2004 to help survivors heal and reclaim their lives."

Noth became a star after starring in five seasons of "Law & Order." When it was time to renegotiate his contract for the sixth season, the show's creator said Noth's pay bump would have been too high, and they would not be able to afford it. Noth was written off the show.

Similarly, Meloni left "SVU" after 12 seasons when he was told he would get an $8 million salary, which would have been a pay cut for him. Since they could not reach an agreement, Meloni left the series, according to The Hollywood Reporter.

The franchise is no stranger to the Emmy Awards. In fact, the original "Law & Order" has 50 nominations, and "SVU" has 23.

Hargitay won the Emmy for best lead actress in a drama series for her role as Detective Olivia Benson in "SVU" in 2006.

"Law & Order: Trial by Jury," which followed the legal proceedings of a criminal case, premiered in 2005, and it lasted only one season before NBC execs decided to pull the plug.

"The ratings performance of the show was inconsistent and ultimately disappointing," then-NBC Entertainment president Kevin Reilly told Entertainment Weekly in 2005. "Over the last number of runs, the show wasn't winning its time period."

When "Law & Order: LA" premiered in 2010, it debuted to low ratings. Wolf attempted to reshape the cast, pushing Alfred Molina and Terrence Howard to the lead roles and firing other cast members, according to Deadline. He even tried an aggressive marketing campaign to draw in more viewers, but the series never made an impact.

It was canceled in 2011 after just one season.

"Law & Order: UK" premiered in 2009 and lasted eight seasons before ending in 2014. It starred Harriet Walter, Freema Agyeman, and Bradley Walsh.

The show modeled itself after the US franchise, which is rare — most UK shows are usually adapted for US audiences, not the other way around.

In 1998, "Exiled: A Law & Order Movie" premiered on NBC, and it followed Detective Mike Logan, played by Noth, as he investigates a murder in Staten Island, New York. The film also features Ice-T, who would later return to the franchise in a different role, as Detective Tutuola on "SVU."

The movie has a 60% audience score on Rotten Tomatoes.

In 2002, "Law & Order: Dead on the Money" was a video game that allowed players to investigate a murder in Central Park. The game featured the voices of "Law & Order" actors Jerry Orbach and S. Epatha Merkerson.

After that game, several more were released, including "Law & Order: Double or Nothing" and "Law & Order: Justice Is Served."