Mariska Hargitay as Det. Olivia Benson on Law & Order: SVU (NBC)

The showrunner for Dick Wolf’s last standing Law & Order program, Special Victims Unit, was struggling to understand how people watch “marathon” sessions of the show he manages. “The children episodes are disturbing, even to us,” said Mr. Leight.

He singled out one such episode, entitled “Friending Emily,” in which detectives go to an FBI office to view images of abused children. Mr. Leight sounded shocked, tired and a little bit horrified over a detail that he and his writers chose to put in the episode. He sounded a lot, in fact, like SVU’s former protagonist, Elliot Stabler.

“There is a kid in diapers whose photo we show,” said Mr. Leight. “We found it on an Internet pornography site. It had 37,000 hits in the last four days.” (Which, it turns out, is the exact line that a government official says during the episode.)

“I mean, a bunch of us on the writing staff have children,” he said. “Nobody really wants to write this stuff. It’s dispiriting.”

The show may upset its own writers, but Law & Order: SVU has outlasted every other show that Dick Wolf created. It’s been two years since NBC nixed the original Law & Order, after 20 seasons. Even after the cancellations of two highly promoted spin-offs, Law & Order: Criminal Intent and Law & Order: Los Angeles (not to mention an ill-fated fourth spin-off called Law & Order: Trial by Jury), SVU is still going strong.

It’s one thing to say that violence sells. It’s another to say that gruesome sexual attacks on the most vulnerable members of society, children, can power the remaining show in an unusually successful franchise. Even last season, when its ratings were at their lowest, SVU was still the sixth most watched show on NBC, ahead of 30 Rock, The Office and everything else in the Thursday night lineup. At its peak, SVU was able to topple the original Law & Order when they were on the air together.

What’s clear: people love watching Special Victims Unit, especially young women and mothers. In fact, since the show launched 13 years ago, females age 18 to 34 have been its most consistent viewers. “Two-thirds of our audience are women,” Mr. Leight said. “I honestly don’t understand why, completely. I don’t get it when parents say they watch the show with their kids, either.”

Lisa Friel, a lawyer who spent nearly 30 years in charge of sex crime prosecutions in the New York City District Attorney’s office, understands the impulse. Ms. Friel, who actually oversaw SVU-style prosecutions at work, used to watch the show with her high-school-age daughter, now 18 and a college freshman.

Some of the subject matter they may have encountered: an episode titled “Consent,” in which a young girl is drugged with GHB; the aforementioned “Friending Emily,” in which an older frat brother conspires with a newer pledge to kidnap and rape a high schooler and then broadcast the videos of her molestation on the Internet; and “Brotherhood,” in which a pledge-master is murdered after raping several women as well as the fraternity’s own pledges.

“It wasn’t like I was watching it with her when she was 7,” Ms. Friel told The Observer. “But when the time was right, when she was old enough and when I thought it was appropriate to start dealing with these issues, it was another way to open the dialogue.”

The writers’ lunchroom is plastered with New York Post and Daily News front covers, enough to extinguish one’s creative juices ... or appetite. Every Law & Order installment has a noted “ripped from the headlines” element, and at times the show has even presaged the news. During Mr. Leight’s tenure, for instance, SVU had an episode (“Personal Fouls”) about a basketball coach using his charity as a conduit for kids he could molest. The show aired “two weeks before the Jerry Sandusky story came out,” Mr. Leight noted, with a hint of pride.

As Gothamist asked its readers at the time, “Not to pull a total conspiracy theory here, but this particular story scales pretty high on the ‘just a coincidence’ scale, don’t you think?”

Mr. Leight explained that the story line wasn’t based any on inside information, but that it wasn’t a complete coincidence, either. SVU has a team of rape counselors, crime survivors, detectives and other law enforcement experts who advise the writers on plot points. “Male-on-male sex crimes was just something that people were telling us was happening,” he said. “The show had never really tackled that issue in a substantial way.”

Confessions" Episode 1003 (NBC Photo: Will Hart)

But the show hasn’t always been an easy sell. When Law & Order: Special Victims Unit premiered in 1999, starring Christopher Meloni and Mariska Hargitay as detectives Elliot Stabler and Olivia Benson, it was criticized for sensationalism. There was just no TV precedent for a series that tackled not just the rape or molestation of adults, but also, with disturbing frequency, of children as well. It wasn’t unusual to have a scene in which a small boy or girl was found wandering around the city, dazed, with blood running down his or her legs.

The most brutal episodes violated yet another TV taboo: some of the kids were murdered as well. Longtime viewers of the show may have seen a 15-year-old found in the bushes, a dead baby discovered in a cooler and a 14-year-old war refugee with a slit throat.

Lisa F. Jackson is one of the show’s critics. “SVU portrays a universe of sexual violence that doesn’t really exist,” said Ms. Jackson, director of the HBO documentary Sex Crimes Unit. To make the film, Ms. Jackson spent two years inside the Manhattan District Attorney’s office with the prosecutors of sex crimes.

“SVU shows a universe that people prefer over the reality of rape and sexual violence,” she said. “In real life, most victims don’t show physical signs of assault, and it’s a lot harder to identify victims because they don’t come forward.”

Especially during the final Christopher Meloni years, SVU seemed intent on pumping up ratings with increasingly outlandish crimes and plot twists. Stabler’s own children were kidnapped, a hackneyed plot recycled from 24.

“I think people are remembering stuff from season 10, season 11,” said Mr. Leight carefully, when asked about the more exploitative aspects of the show’s story lines. “I think toward the end of the Meloni era, it got a little ... fetishistic. It was like anything else: you had these great writers on the show for 10 years working with the talented [original showrunner] Neal Baer, and they keep pushing the limits, pushing the limits. When we came in two years ago, our whole idea was to bring the show back to the basics.”

SVU has sailed past its 300th episode, is well into its 14th season, and has survived the loss of one of its two stars. It might be worth considering that there is something in it besides cheap thrills. It’s hard to think of SVU as entertaining. Riveting, perhaps.

Mr. Leight would have us believe that SVU exists as a public service, and that the writers get no pleasure in creating these dark stories, especially if they involve children. Like SVU’s relation to real-life sex crimes, his contention probably has some element of the truth, but isn’t the whole story.

During our interview, Mr. Leight asked us what we thought of the recent accusations that Kevin Clash, the voice of Elmo, had once been sexually involved with an underage teen.

We said we thought it wouldn’t be too long before an episode about a child-molesting puppeteer would make it onto SVU.

Mr. Leight coughed and was quiet for a moment. “Yeah ... probably not for a while.”

That night, Mr. Leight would write on @warrenleightTV Twitter account, “Memo to: FBI/CIA/NATO/SesameStreet From:SVU Writers’ Room—Please slow it down, we’re having a hard time getting this all down.”