“In the criminal justice system, the people are represented by two separate, yet equally important, groups: the police, who investigate crime; and the district attorneys, who prosecute the offenders. These are their stories.”

This is something that everyone who owned a television in the nineties heard. And practically everyone today has heard some version of it, because it’s the opening line of every episode of the crime drama Law & Order, a television series that aired for two decades on NBC and was so popular that it spawned its own universe of spin-offs that continue to be popular to this day, but the one that started it all first began airing in 1990.

The series was created by a man named Dick Wolf. Wolf, a Manhattan-raised New Yorker, started out as an advertising copywriter at the Benton & Bowles ad agency creating commercial slogans for companies like Crest and National Airlines, all the while writing screenplays on the side with the hope of having a film career. He actually had success getting a few screenplays produced when he moved to L.A., the most well-received being the screenplay for the 1988 romantic thriller Masquerade starring Rob Lowe. But before that he began writing for television, and this would end up being the more fruitful career path. After Emmy-nominated Wolf wrote for Hill Street Blues, he became a producer on Miami Vice and created a few of his own shows in the late ’80s and early ’90s. Can you guess which one was the most popular?

Law & Order was both a police procedural and a legal drama that ran on NBC for 20 seasons from 1990 to 2010. Set and filmed in New York City, each episode focused on one crime but was divided in half, with the first half dedicated to the crime investigation and the lives of the detectives at the NYC Police Department, and the second half dedicated to the legal ramifications at the door of the Manhattan District Attorney’s Office followed by a courtroom verdict.

The first season starred George Dzundza as Sergeant Max Greevey, Chris Noth as Junior Detective Mike Logan, Dann Florek as Captain Donald Cragen, Michael Moriarty as Executive Assistant District Attorney Ben Stone, Richard Brooks as Assistant D.A. Paul Robinette and Steven Hill as D.A. Adam Schiff.

The series went on to include Jerry Orbach as Detective Lennie Briscoe, S. Epatha Merkerson as Lieutenant Anita Van Buren, Sam Waterston as Executive Assistant D.A. Jack McCoy and Jesse L. Martin as Detective Ed Green. Other actors who have had main roles on the show include Alana de la Garza, Paul Sorvino, Benjamin Bratt, Angie Harmon, Dianne Wiest, Dennis Farina, Michael Imperioli, Jeremy Sisto, Anthony Anderson and J.K. Simmons.

Mike Post created the minimalistic but stylish theme song, as well as the famous “clang clang” sound that starts each episode and shows up during scene transitions, with Post purposely imitating the sound of a judge’s gavel. The fictional crimes in the show were often based on real crimes, which gives the series an air of realism that makes it especially compelling. And multiple television crime dramas have done the same thing since Law & Order gained popularity.

Another special thing about the series was Dick Wolf’s insistence that it be filmed in New York. NBC wanted to film in L.A. (like most shows at the time), but Wolf won that battle. And the New York filming location gave the producers easy access to some of the most talented theater-trained guest stars. One of the things Law & Order is known for is having amazing guest stars, a list that over its two decades on the air has included people like Robert Klein, Edie Falco, Dominic Chianese, Julia Roberts, Ellen Pompeo, Michael McKean, John Slattery, Mandy Patinkin, Lynda Carter, Kathleen Turner, Jennifer Beals, Jim Gaffigan, Rob Corrdry, Ernie Hudson, Elliott Gould, Samantha Bee, Debra Winger, Anna Chlumsky, Tony Hale and Anna Gunn. Even then-New York mayors Rudy Giuliani and Michael Bloomberg have appeared as themselves on the show.

The drama (the police drama, the legal drama and the personal character drama) in this series is often highly regarded as some of the best on television and the show even won the Primetime Emmy for Outstanding Drama Series in 1997. Even viewers loved it, as evidenced by its consistent domination in the ratings.

More than a decade after it ended, NBC is bringing the series back for a 21st season in 2022 that will introduce Jeffrey Donovan, Hugh Dancy, Camryn Manheim and Odelya Halevi to the main cast and feature the returns of Anthony Anderson as Detective Kevin Bernard and Sam Waterston as D.A. Jack McCoy.

The success of Law & Order led to many spin-offs, like the hugely popular and long-running Law & Order: Special Victims Unit (1999-present) which stars Mariska Hargitay as Detective (now Captain) Olivia Benson and originally featured a cast that included Christopher Meloni, Richard Belzer, Dann Florek and Michelle Hurd and went on to include Ice-T. This series focuses on sexual offenses like rape, pedophilia, domestic violence and abuse.

Law & Order: Criminal Intent (2001-11) starred Vincent D’onofrio as Detective Robert Goren and Kathryn Erbe as his partner Detective Alexandra Eames who try to infiltrate the minds of the criminals they are investigating to understand their “intent.”

Law & Order: Trial by Jury (2005-06) starred Bebe Neuwirth as Homicide Bureau Chief Tracey Kibre, Amy Carlson as ADA Kelly Gaffney and Jerry Orbach reprising his role as Lennie Briscoe in a 13-episode series that focused on the legal teams of the prosecution and defense and was the first Law & Order series to be cancelled due to low ratings.

Law & Order: L.A. (2010-11) starred Alfred Molina, Skeet Ulrich, Corey Stoll, Terrence Howard, Alana de la Garza, Regina Hall and Megan Boone and was the first Law & Order series to be set outside of New York. It lasted one season.

Law & Order True Crime (2017) is an anthology series that focuses on one crime over the course of a single season, the first season focusing on the Menendez murders and starring Edie Falco as D.A. Leslie Abramson and Gus Halper and Miles Gaston Villanueva as Erik and Lyle Menendez. The show is on hiatus right now after airing once in 2017.

Law & Order: Organized Crime (2021-present) stars Christopher Meloni reprising his SVU role as Elliot Stabler and follows a single-arc plot across multiple episodes.

There was also a British adaptation called Law & Order: UK which aired on ITV from 2009 to 2014 and was the first American drama series to be adapted for British television. Plus Dick Wolf and Wolf Entertainment went on to have more success on NBC with Derek Haas and Michael Brandt’s drama Chicago Fire which is set in the Chicago Fire Department and has led to a Chicago TV universe that has included Chicago P.D. and Chicago Med, as well as on CBS with Dick Wolf and Craig Turk’s FBI, which led to the spin-offs FBI: Most Wanted and FBI: International, all of which would not have existed if not for Law & Order.