Earlier this month in Nashville, a few thousand people gathered at a four-star resort to revel in murder, mayhem, serial killers and cold cases — plus some Chardonnay at a little “Wine & Crime” happening.

The second annual CrimeCon provided what no amount of binge-watching or reading could not: the opportunity for true crime addicts — and they are legion — to meet and mingle with stars of the genre.

Here’s Ryan Ferguson, the hot young Missouri man who spent almost 10 years in prison for murder! Here’s Erin Moriarty, the “48 Hours” correspondent who helped get Ferguson’s wrongful conviction overturned! Also milling about: Kelly Siegler, the terrifying former Texas prosecutor-turned-“Cold Justice” star; Juan Martinez, who successfully convicted Jodi Arias in the brutal murder of her ex-boyfriend; and Callahan Walsh, a child advocate for the National Center for Missing and Exploited Children.

It was the vanishing of Callahan’s brother, Adam, in 1981 — just two years after 6-year-old Etan Patz disappeared from the streets of SoHo — that hit the marrow of every parent’s worst fear and simultaneously ignited a national obsession with true crime.

In the aftermath of Adam Walsh’s disappearance, his father John launched “America’s Most Wanted.” That series, which Walsh hosted, ran for 25 seasons and helped capture 1,200 fugitives.

Now a Hollywood star as much as a victim’s advocate, John Walsh has since disclosed gruesome details of his son’s murder. While speaking at a Starz panel at Manhattan’s SoHo House in 2014, Walsh offered up this grisly morsel: “People don’t know this, but [police] kept Adam’s severed head in the morgue for 27 years, saying you can’t bury your child because it’s an open capital murder,” Walsh said. “We could never get Adam’s remains while the case was botched.”

This chilling anecdote, offered in a showbiz setting, illustrates today’s popular conflation of real gore as mass entertainment. CrimeCon is its ultimate result, with fans paying anywhere from $349 to $799 for tickets.

Headlining this year’s event was HLN’s Nancy Grace, who spoke for an hour with terrifying evangelical fervor.

“Lady Justice will call,” Grace told the crowd in her deep Southern drawl. “My question is: Will you pick up?”

Switching with disturbing ease between tales of her youthful move to New York (“with two boxes of clothes and $300 — what could go wrong?”) to the tearful recounting of a 3-year-old’s rape, Grace took her rapt audience through the life of a prosecutor turned TV star. That Grace has a dubious reputation as tragedy vulture with a penchant for reckless accusations did not bother this crowd.

“When I put my foot on the ground,” Grace said, “the Devil will say, ‘Oh no! She’s up!’ ”

Second only to Grace were the correspondents of NBC’s “Dateline,” whose panel began with a clip of super-fan Bill Hader imitating, among others, breakout star Keith Morrison.

“Oh, Keith,” said 36-year-old Thashana McQuiston. Morrison, with his droll affect and eternal bemusement in the face of atrocity, was a huge draw.

“The voice pulls you in, but it’s just his whole demeanor,” she said. “He’s a very charismatic person. There’s just something very attractive about him. He’s effortless.”

“I’m ready to jump up and down!” said Jennifer, 46, a mother of one from Ohio. “Keith! He’s such a great storyteller. Even though the stories are horrible.”

The stories are horrible. Therein lies the appeal.

“Dateline” has been on the air for 26 years, airing new episodes twice a week. “48 Hours,” its nearest competitor, went all-true-crime in 2004. The Oxygen channel, which co-sponsored this year’s CrimeCon, is exclusively true crime. So is the ID Channel, which reports 60 percent female viewership. TLC and OWN, which also skew heavily female, rely heavily on recycled true-crime programming — “Dateline” reruns are frequently found on both networks.

So unequivocal is the audience’s love that there’s the “cozy mystery” subgenre, so named because these murders happen in a small, picturesque villages, sex and violence tamped down. In short: just some good old-fashioned homicides!

By and large, books about true crime have long regarded as little more than pulp, but that has begun to change. “Killers of the Flower Moon,” by the brilliant New Yorker writer David Grann, was one of 2017’s bestsellers, and the film rights sold for $5 million, a rare price for an option.

“I’ll Be Gone in the Dark: One Woman’s Obsessive Search for the Golden State Killer,” by the late Michelle McNamara, not only became an instant critical and commercial hit upon release last February but helped solve one of California’s oldest cold cases, with Joseph James DeAngelo arrested in California last month. Though law enforcement did not give McNamara credit, her book unquestionably sparked pressure to solve the case.

“It was her dream,” McNamara’s husband Patton Oswalt said. “She always said, ‘I don’t care about credit. I want to know that he’s in jail.’ ”

Here, too, is a powerful and recent phenomenon: The internet can turn anyone into an online detective who gets results.

Attendance at CrimeCon was about 80 percent women, which tracks with the genre’s television viewership: Most true crime fans are female. Experts in the field, and women themselves, will tell you that they follow true crime to learn what not to do, how not to become a victim.

“Two-thirds of my forensic psychology class skews female,” says John White, a former sergeant with the Dallas Police Department and current professor at Stockton University in New Jersey. (He has also contributed to “Criminal Minds” on CBS and Lifetime’s “Killer Profile” series.)

White, a featured speaker at the convention, believes that women regard true crime stories as a means of protection, by nature “very cognizant of their own mortality and the ways people can hurt you.”

Critics of the genre identify a voyeuristic thrill in the viewing of mutilated female bodies. Feminist author Germaine Greer recently argued, to great controversy, that women are overwhelmingly drawn to true crime as a way of exorcising fantasies of being raped and overpowered. She also blamed female consumers of crime stories for the exponential increase in images of our own victimhood.

“Women make up between 60 and 80 percent of readers of crime fiction,” Greer wrote. “Dedicated true crime channels are principally watched by women. Strange as it must seem, the endless array of female cadavers laid out on slabs and dragged out of the undergrowth in crime drama on TV is designed to reel in a mainly female audience.”

Crime writer Val McDermid refuted that notion, telling the Guardian that “this is a complicated and nuanced issue . . . I do think women are drawn to watching crime dramas because we have been conditioned into thinking of ourselves as potential victims, and we want to understand how that prediction comes true. There’s also a sense in which it feels almost talismanic, like watching lightning striking someone else’s house — ‘Thank God it’s not me.’”

Many of the women at CrimeCon couldn’t quite articulate why they’re so magnetized, let alone why they might take part in one experience at the convention in which they were blindfolded, bound and made to listen to a serial killer recite all the horrific things he would do to them.

There is nothing to be learned from such an experiment. It holds no benefit. It is pure shock and horror, and it’s difficult to fathom why, say, a middle-class suburban woman from the Midwest would willingly submit. This is where Greer has a point: What else could such fake brutalization be about other than kicks and kinks?

To her thesis about rape and bondage fantasies, Greer referenced a University of Texas study that found one-third of women often have rape fantasies. “In my view,” she wrote, “the fantasy is commoner than these figures suggest.”

‘I believe everyone has a rubbernecking aspect to them. If it’s not your car accident on the drive home, it’s the crime you weren’t a victim of.’ - Jim Fitzgerald

Yet many women, including those at CrimeCon, insist it’s not that complicated. They just love a good mystery.

“It’s the psychology of [the killer], the why,” said 30-year-old Jackie Harkrader. “I’m really excited about the Golden State Killer. My all-time favorite case is Jon-Benet Ramsey. I wish I could solve it.”

Harkrader works in Child Protective Services but doesn’t see her Jon-Benet fixation as anything other than an irresistible tug to an unsolved crime. It’s not necessarily the epitome of her worst fears about what could happen to a child, nor a means of somehow protecting a child against grievous harm. She loves mysteries and serial killers, she says, nothing more.

“It’s just their minds,” Harkrader says. “Their pasts. What made them the way they are, the psychology.” CrimeCon, she says, feels “exhilarating.”

And why shouldn’t it? As with books, docuseries such as NPR’s “Serial,” Netflix’s “Making a Murderer” and “Mindhunter,” and HBO’s “The Jinx” tell multi-layered, open-ended stories in sophisticated yet accessible ways. These stories allow women, especially, to work through our worst fears from a safe distance — fears that span generations, locations and class.

It’s this very combination of high-low, the demographic crossover between the NPR listener and the basic-cable addict, that convinced CrimeCon founder Kevin Balfe there was an audience for live experience.

“You have amazing content creators and millions of fans,” Balfe says. “It hits all the right notes for what you would do when you come together.”

Also benefiting are former FBI and law enforcement, who can now find second lives feeding Hollywood’s insatiable demand for content. The dream is to maybe become a go-to talking head on 24-hour cable news, then a consultant on a show or film, graduate to screenwriting, and ultimately reach the pinnacle: become the hero of the story itself, the subject of a book or movie made about you.

It’s seductive, the notion that a former special agent, by job requirement toiling in the shadows, finally attains glory. It’s part of the lure for speakers here, who welcome their fans with the ease and expectation of A-list stars.

“Jim Fitzgerald,” says a well-dressed older man, extending his hand. When faced with a puzzled expression, he’ll gently remind you. “I did the Unabomber. ‘Manhunt.’”

Ah, yes — Jim Fitzgerald, the former FBI profiler who identified Ted Kaczynski as the Unabomber and was played by Sam Worthington in the recent docuseries.

So: What does Fitzgerald make of such morbid attractions?

“I believe everyone has a rubbernecking aspect to them,” he says, a line rapidly forming to meet him. “If it’s not your car accident on the drive home, it’s the crime you weren’t a victim of.”

Presiding over all things CrimeCon is Jim Clemente, a former FBI agent who founded XG Productions (as in “ex-G-man”). His company consults and creates content, and XG is a major presence here. Clemente’s goal is for these attendees to leave on a high, to feel as though they have as much chance of cracking a cold case as the most seasoned detective. Or, failing that, Keith Morrison.

The FBI, Clemente says, needs you, the amateur sleuth. Countless victims need everyone at CrimeCon. Here is the refracted glory, a storied former agent pleading with normal women, moms and teachers and retirees, for help in catching not just the bad guys but the worst of the worst.

“We have a lot of work to do,” Clemente said at the closing event. “Many of you understand these things in a way the outside world does not . . . We’ll get more justice for victims and their families, and the world will see it.”

Maybe, maybe not. Until then: There’s CrimeCon 2019, tickets going for $229-$1,199, on sale now.