When Tutuola joined the show, his previous background was in Narcotics, which was the job of Ice-T's character in New Jack City.
And when Lee Tergesen guest-starred as a suspect in the episode "Savior," he and Elliot got very touchy-feely in the interrogation room as they prayed together, undoubtedly a reference to their intimate times in prison together.
Harold Perrineau recently played a wheelchair-using ex-con who is now going back to prison for several rapes committed before he became a paraplegic, much as he did on Oz (though sadly this was after Christopher Meloni's departure)
Reg E. Cathey's character Barry Querns also bears the same surname as the character he played on Oz. Given the numerous other Oz allusions in the show, this was probably an intentional Shout-Out.
The Cold Opening for "Loophole" had Bill Goldberg as a perp hopped up on PCP. Elliot clocks him in the back of the head with a fire extinguisher and gets trashed for his efforts. What finally stops the rage? Fin with a chair to the head.
Amaro at one point visits a Cold Case unit. Also, "Secrets Exhumed" begins the same way most Cold Case episodes did, with one character (in this case, Munch) saying that they'd gotten a break in an old case. Munch hands the case file to Amaro.
In another episode, Cassidy mockingly refers to Amaro as Ricky Ricardo. Danny Pino portrayed Desi Arnaz in the 2003 TV movie Lucy.
Anyone old enough to remember Donal Logue's Jimmy the Cab Driver sketches on MTV should smile at Lt. Murphy's perp disguise in "Spring Awakening."
Pablo Schreiber who plays William Lewis, the raging psychopath (and briefly prisoner) on this series was also moonlighting as a slightly less psychopathic prison guard on the Netflix series Orange Is the New Black.
While Schreiber played a criminal on this series and a C.O. on another series, he actually portrayed a completely sane, crime-fighting detective on the short-lived cop drama Ironside (2013), which coincidentally aired right after SVU during the Wednesday night line-up.
Jefferson Mays plays an M.E. named Carl Ruddnick, who cross dresses frequently for the sake of covering up his crimes. Mays was nominated for a Tony for his role in A Gentleman's Guide to Love and Murder as the D'Ysquith Family - a role which required him to master quick changes in order to play multiple male and female roles within the same family. The difference here is that Mays' characters are the ones that are murdered over the course of the play.
SVU has had exactly three episodes featuring French (or Franco-African) characters, two of which just so happened to be when Detective Beck was on the show. Interestingly, it appears that the writers actually showed restraint on this one, seeing as Connie Nielsen speaks eight languages.
Averted when an episode shows most of the characters watching an Expy of American Idol. The only one not shown singing along is Barba, who is played by Broadway legend Raúl Esparza.
Murphy's repeated undercover assignments show off Donal Logue's ability to do an Irish accent.
Creator Backlash: Ice-T (who's a big gaming fan) wasn't fond of "Intimidation Games," as he made clear on his Twitter after it aired.
The Danza: In the episode "Friending Emily," Taylor Spreitler guest stars as the victim's sister, Taylor Culphers.
Fake American: Adam Beach, who played Chester Lake, is from Manitoba.
Fandom Nod: in 11x13, "P.C.", Kathy Griffin's lesbian character coming onto Liv. The reasons she gives for her mistake are pretty much the same ones fans have been using for their Slash Fic since, oh, the start of the show. Olivia asking, "Why does everyone think I'm a lesbian?", Olivia fooling the suspect into confessing by pretending to be a lesbian, swaggering into the interrogation room in a leather jacket, it has it all.
Averted in season 17 with Kelli Giddish's pregnancy. There's almost a Running Gag of the characters telling Rollins to stop pushing herself so hard when she's pregnant. The gag becomes much less funny when she has to be put on bed rest.
During the first half of the 2011 season, the episode "Missing Pieces" in which a mother claims that her car was stolen with her young son still buckled into his car seat bore more than a passing resemblance to the still-unfolding Sky Metalwala case.
"Personal Fouls" which revolves around a well-respected coach who uses a children's charity to molest young boys originally aired a few weeks before the Penn State molestation story broke. However, according to The Other Wiki, this one was actually based on a different sports abuse case.
In the episode "Imprisoned Lives," based on Ariel Castro but written before he was convicted, a scene with not-Castro allocuting about why he took the girls had to be cut when it ended up matching Castro's almost word for word.
Tragically, this real life case is disturbingly similar to both the season 4 episode "Resilience," in which a father artificially inseminates his teenage daughter, and, to lesser extent, the season 5 episode "Home," where a mother is an extreme control freak over her home-schooled children.
Mean Character, Nice Actor: Pablo Schreiber's amazing performance as the vile William Lewis caused many fans of the show to fuse his character with his real life persona; to the point where he was receiving hateful and threatening messages. Schreiber himself has admitted that in the future he plans on playing the 'good guy' more often so people can see what a truly sweet person he is. To contrast, there are a handful of photos on the internet of he and his on-screen arch enemy (Mariska Hargitay) being quite chummy with one another when they weren't filming.
Kelli Giddish's pregnancy was incorporated into Rollins' story in Season 17, resulting in Giddish's own baby boy being brought to set to play Rollins' daughter Jesse in a few episodes.
Reality Subtext: Barba and Benson's close onscreen friendship springs from the fact that Raul Esparza and Mariska Hargitay clicked with each other from their first meeting and rapidly became close in real life (Esparza has said on more than one occasion that working with Hargitay is his favorite thing about the show).
Recycled Script: SVU has a nasty habit of doing this with the original and then adding The Unfair Sex aspects to the plot. For example the episode "Bitter Fruit" a young girl is kidnapped between school and her music lesson and later killed. While it was questionable exactly who did it due to the fact that they both were Jerkasses. In the end it turns out it was the mother and while she tried to blame her ex husband she was given the maximum sentence. However “Shattered” had the exact same plot only they eliminated all of the ex husbands jerkassiness while transforming the mother into the biggest Misandrist that they possibly could. It turns out that it was the father who kidnapped his son even though that made absolutely no sense.
Technology Marches On: Inevitable given that SVU premiered in 1999. The show's adjustment to the existence of social media occasionally veers into the hilarious.
Oftens swerves into their Technologically Blind Elders — the characters are frequently exasperated by the Evil Internet, but the writers themselves have a very shaky grasp of how popular websites work (see their definition of "blogging" as "daily visits to one website" and describing a Twitter account as having thousands of "friends" and featuring posts from many different users. That's...not how that works.)
Warren Leight having Olivia describe her relationship with Elliot as one where she was completely unable to grow. Even the positive interpretation of that, that she held herself back because she was nursing unrequited love for him, mightily pissed fans off.
Leight's use of characters from seasons beyond his era has resulted in major character derailment with half-assed justifications for those developments. Major examples include:
Dr. George Huang, who worked with SVU from seasons 2-12 (with occasional episodes in 13, 14, and 15), returns for an episode in season 17 to help another lawyer win her case by stating that Liv coerced a confession out of him. Not only was Liv pissed, but Leight has stated that there's little hope for Huang and Liv's professional relationship because Liv holds grudges.
As of mid-season 17, Liv is dating IAB Captain Ed Tucker - the same officer who relentlessly persecuted various SVU officers (including Liv herself!) over seasons 1-15. When asked what could have led to this development, Leight stated that Liv has decided to let go of the past and that the relationship makes sense since Liv hasn't had time to look elsewhere due to having a toddler at home. What.
It was originally going to be revealed that Olivia's mother lied about being raped.
Originally, upon Homicide's cancellation and after hearing that Benjamin Bratt was leaving the original series, Belzer suggested to Dick Wolf that Munch become Lennie Briscoe's new partner, since they had originally teamed in three Homicide crossovers. Wolf loved the idea, but had already cast Jesse L. Martin as Det. Ed Green.
This lady played two different characters in season 4 and season 5.
Ice-T normally plays Fin, but in the in-universe movie Exiled he plays Seymour Stockton, a pimp.
The newest ADA, Gillian Hardwicke, is played by Melissa Sagemiller, who made her acting debut in an episode of the first season.
Hayden Panettiere has played two different characters within 5 years (in season 2 and season 6).
Liza Lapira has played two other characters besides a lab tech, see here.
KyleGallner has appeared on the show as two different characters, in Season 4 and Season 9.
Andre Braugher as an attorney. Kinda weird, given that Homicide: Life On The Street exists in the same universe as the Law & Order series. It works because Frank Pembleton never appeared on SVU and (aside from Munch) never met or worked with any of the SVU characters. Lampshaded when Munch greets Ellis in a familiar (and sarcastic) way, and Ellis replies "Have we met?"
Tamara Tunie appeared as a defense attorney in the Law & Order episode "Deadbeat" before she landed a role in SVU as Dr. Melinda Warner.
Raúl Esparza was on both the original series and Criminal Intent in the episodes "Blackmail" and "Lady's Man", respectively.
Lothaire Bluteau seems to be the guy the producers have on speed dial whenever they need a vaguely European-ish creep (although the actor is actually Canadian), having played such roles in three episodes. He's also appeared as separate characters on Criminal Intent and Trial by Jury.
Sherri Parker Lee played a grifter suspect in "Greed" and a protective older sister who was also guilty of assault and murder in "Mother."
Kelli Giddish, who plays Rollins, played the role of a rape victim in the episode "Outsider."
Peter Scanavino, who plays Carisi, played a man who was a victim of rape as a child in "Monster's Legacy."
He also portrayed an armed robber in the Criminal Intent episode "Diamond Dogs" (season 5), and had a small role in the Trial by Jury episode "Boys Will Be Boys."