On a cool evening in October, Alain Malcolm, 20, walked into a vacant two-story colonial house in Bristol, Connecticut. Two members of a local internet vigilante group — who regularly try to expose and shame alleged child predators they entice online — were waiting for him.

Malcolm was tall and handsome. The oldest son of Jamaican immigrants, he wholly subscribed to the idea of the American dream. In high school, Malcolm was vice president of the Future Business Leaders of America club, assistant captain of the tennis and swim teams and a member of the student council and Model United Nations. He started a social marketing business at 15.

After graduating in 2016, Malcolm filled his Instagram and Facebook feeds with photos of New York high-rises, bathroom selfies in three-piece suits and links to news articles in which he was featured. He went to community college while working as a junior buyer for a local circuit-board manufacturer and was the subject of a Connecticut Public Television series that profiled recent high school graduates. Earlier this year, he was named one of Litchfield County’s 40 Leaders Under 40.

Alain Malcolm's entry in his high school yearbook. Ron Antonelli / for NBC News

Malcolm was also gay, which was difficult growing up in a religious family in Torrington, a sleepy former mill town in the northwest part of the state, friends said.

“It’s not easy to be black, Jamaican, a Jehovah’s Witness and gay in Torrington, Connecticut,” said Allie Morrissey, a friend of Malcolm’s.

Starting in high school, Malcolm used apps like Tinder and Grindr to meet men from around the state, friends said. On that October night, he had come to Bristol to meet someone younger, purportedly a 14-year-old boy “going on 15,” according to a video posted by the digital vigilante group known as POPSquad.

When Malcolm arrived, he found that there was no boy — there was only POPSquad. For the 126th time in two years, the group — an acronym for Prey on Predators — had catfished a man on the internet, posing as an underage teen on hookup apps and luring him into a meetup, this time at an empty home whose owner allows it to be used for the group’s stings, according to POPSquad.

Like the others before him, Malcolm was greeted by Shane Erdmann, 31, better known by his alias “Incognito,” who questioned and berated Malcolm as the camera rolled. (The entire encounter was posted on Facebook the next day, though it was later removed. NBC News spoke to three people who watched it — two friends of Malcolm’s and one POPSquad fan — and described its contents.)

Confronting Malcolm with copies of the alleged sexual online messages sent to a POPSquad member, Erdmann asked: Why had Malcolm come? What disgusting things was he planning to do? What would his family think?

“I don’t have anything to live for,” Malcolm said as he stared at the ground.

Although his targets may initially believe otherwise, Erdmann isn’t with the police, and Malcolm wasn’t required to talk with POPSquad. As Malcolm walked to his car, Erdmann followed to film his license plate, reading the numbers aloud, “for the camera,” Erdmann said.

“Your family is going to see this. How do you feel?” Erdmann asked, according to people who saw the video.

Malcolm honked twice as he sped away, driving 30 minutes back home to his parents’ house in Torrington, where he hanged himself.

‘A MOB JUSTICE VIGILANTE MENTALITY’

POPSquad is one of dozens of similar online groups across the country unified by what they say is a mission to expose and shame people they allege are or could become sexual predators, according to an NBC News review of these groups on Facebook. The idea isn’t new — the NBC News “Dateline” show mined the same territory in its special series, “To Catch a Predator,” from 2004 to 2007. Ratings soared, and the network described it as a public service, but in three years the series was over, after drawing negative news coverage, advertiser wariness and a lawsuit from the family of a target who killed himself, which was later settled, with both parties saying only that it had “been amicably resolved."

There have been several copycats of “To Catch a Predator,” including Ontario construction worker Justin Payne, who ensnared dozens of men by 2015. In British Columbia, Ryan LaForge made a name (and a criminal record, pleading guilty to two counts of assault) with his group, Creep Catchers, and in Michigan, Zach Sweers caught potential predators under the name “Anxiety War” until 2016, when he settled two civil lawsuits from targets.

Now, thanks in part to social media, these groups have multiplied rapidly in recent months, propelled by a rabid and growing fanbase, according to law enforcement officials and Facebook data.

The NBC News review found more than 30 similar operations on Facebook across 23 states. Most have formed in the last year, finding an audience and influence on Facebook, where hundreds of thousands of users like and follow them, watch videos of their stings and support their efforts with donations and the purchase of branded merchandise.

Truckers Against Predators, started in June by a St. Louis truck driver, Anthony Greene, has quickly become the genre’s most popular group, with 92,000 Facebook followers, according to NBC News’ review of the groups. Greene, who uses a team of decoys to fish for potential predators to berate in gas station parking lots, said he was inspired by Shane Coyle, who runs Facebook’s second-most-popular predator hunter group, Prank Call Mafia. Coyle, a former MTV reality show contestant with a criminal record unrelated to the group, disguises his voice like a minor to lure men to Florida meetups.

Sometimes, though not often, a sting by these groups ends in an arrest of the potential predator by local police. In the two years since Erdmann founded POPSquad, the group has recorded over 131 stings and claims to have been involved in 14 arrests, all of which NBC News has confirmed, though not all of the men were charged with crimes related to POPSquad’s videos.

Nonetheless, many law enforcement officers object to the groups and consider them dangerous vigilantes.

Even when police don’t get involved, the predator hunters and their loyal followers are ready to exact their own form of justice on social media, making sure that the alleged predator’s video is seen by his family, friends and employers.

Frank Norris, 32, a POPSquad follower from Cheshire, Connecticut, is one self-appointed enforcer.

“I’ve called state police, I’ve called family members and I say, ‘This is your family member,’ so they can distance themselves,” Norris said of the men caught on POPSquad’s videos. “I think it’s disgusting. I think it’s a huge problem. That's why I’m active. You want to shame these people.”

These online hunters are tapping into a hunger for vengeance, said Steven Kohm, a cultural criminologist at the University of Winnipeg.

“Criminal justice used to be emotional and participatory,” Kohm said. “Over the last 100 years, it’s become mostly hidden and dominated by professionals. People are yearning to reconnect with the punitive emotional core of the justice system. These groups focusing on the pedophile, a universally reviled category, helps them connect with the lost aspect of the justice system.”

Kohm linked the hunters to the popularity of internet sleuthing, at a time of deep mistrust in authority. It appears to be the same impulse that fueled Qanon, "pizzagate" and other popular conspiracy theories obsessively “investigated” by online groups.

“It’s a mob-justice vigilante mentality,” Kohm said.

Facebook is a key piece of the groups’ strategy.

“These kind of stories, visceral and violent, are more likely to be shared on Facebook,” said Mitali Thakor, an assistant professor at Wesleyan University and expert on digital vigilantism and online child exploitation.

Facebook’s focus on local stories and groups could also amplify the predator hunters’ content, Thakor said.

“You’re more likely to see these kind of local stories because Facebook suggests content based on location, and because it’s hyper-localized it seems real and relevant, like this content is from your community newspaper.”

Facebook told NBC News that it is aware of these groups and does not ban them outright, although much of what they do appears to violate Facebook’s rules against shaming or cyberbullying.

“We want people to use Facebook and our products to raise awareness about threats to public safety, including those who may pose harm to children,” a company spokesperson said in a statement to NBC News. “However, we do not want people to use Facebook to facilitate vigilante violence. That’s why we have policies against threatening real-world harm and to protect people’s privacy if they are being publicly shamed. We will remove content that violates these policies when it is reported.”

Facebook does not allow posts that “reveal personally identifiable information" or amount to cyberbullying, the spokesperson said. The company reviews posts when they are flagged.

After an inquiry from NBC News, Facebook temporarily suspended several predator hunter accounts, removed some individual posts and deleted at least one group entirely. Some groups voluntarily removed their own pages to escape what they saw as a purge. POPSquad appeared to be unaffected.

"There's nothing anybody can do to stop us.”

Anthony Greene of Truckers Against Predators was among the users disciplined by Facebook. In a Facebook Live video, Greene told his followers he was locked out of his account, in "Facebook jail" for the next 30 days.

"Things will be all right,” Greene said. “We're 90,000 strong, guys. There's nothing anybody can do to stop us.”

A VICTIM OF POPSQUAD

On Oct. 20, a day after filming Malcolm’s panicked response to the sting, POPSquad labeled him No. 126 and posted the video on Facebook, to 17,000 followers.

It didn’t take long for the POPSquad video to reach Torrington. At the same time, news of Malcolm’s death the previous evening was making its way through town and into the comments on POPSquad’s Facebook page. Even after locals commented that Malcolm had died and linked to his obituary, many POPSquad fans responded with glee.

“The comments were awful,” said Morrissey, 20, a high school friend of Malcolm’s who saw the video online. “Terrible things like: ‘We’re so happy he killed himself. Thank you God for taking another disgusting person off the Earth.’”

Marielle Franco, left, and Allie Morrissey were friends of Alain Malcolm. Ron Antonelli / for NBC News

“It wasn’t even people our age,” added Marielle Franco, 20, another friend. “It was like people my mom’s age.”

POPSquad took down the video after less than 24 hours and replaced it with a post in which the group vowed to continue its work “without hesitation.”

“It will be natural to feel sad if something happens to a predator, but remember. He is not the innocent,” the post said. “He is not a victim. He tried to create a victim. This catch was no different than all the others before it and his actions are his and his alone.”

Erdmann declined to comment on the video of Malcolm and responded to NBC News’ follow-up questions with a threat to sue.

Malcolm’s family did not respond to requests for comment.

There is an open investigation into Malcolm’s death, according to Torrington Police Department Lt. Bart Barone.

“We’re still trying to get in touch with POPSquad and see what the whole thing was about,” Barone said. “It really was a sad situation. He was a young kid.”

POPSQUAD’S TACTICS

Erdmann, who is thin and covered in tattoos, runs POPSquad from an abandoned factory in Bristol, Connecticut. He and four volunteer team members work in an office lit by black lights and security monitors to catfish potential predators, edit videos and maintain the POPSquad website.

A former self-described “hustler,” and staple of the early-aughts Connecticut rap scene, Erdmann later hyped WakeUpNow, a Utah-based multilevel marketing company that targeted the hip-hop community. He is currently on probation for an unrelated 2016 felony drug conviction and now makes money from selling original music along with POPSquad hats and sweatshirts, and soliciting donations from his followers.

“I've been an entrepreneur for a long time,” Erdmann said. "I’m using the same entrepreneur skill sets that I was when I got into trouble, but not the same products. I create the product now."

While Erdmann wouldn’t talk about Malcolm on the record, he was eager to rattle off the names of POPSquad targets and their number on his list.

“In this field, sex crimes, no one can hold a candle to me."

Among his highest profile catches that ended in related arrests and guilty pleas: Scott Backer, No. 5, a former associate dean of students at Wesleyan who pleaded guilty to enticing a minor and was sentenced to probation after Erdmann confronted him in a Walmart girls section; James Batt, No. 33, a high school special education teacher whom Erdmann filmed at a Dunkin’ Donuts and who pleaded guilty to child pornography possession; Cole Sutton, No. 46, a school photographer who pleaded guilty to risk of injury to a minor and is serving a five-year suspended sentence; and Keith Dubin, No. 60, who pleaded guilty to risk of injury to a minor and possession of child pornography and is serving an 18-month sentence.

But POPSquad's very involvement may hinder prosecution.

"It was one of the reasons why they gave my client some leniency,” Backer’s attorney, Anthony Spinella, said of the state's attorney in Hartford who prosecuted the case, who declined to comment. “Putting these vigilantes on the stand would have been be a nightmare.”

Lawyers for the other men did not respond to requests for comment.

These operations have been the subject of dozens of local news stories that praise POPSquad’s work. Although Erdmann’s identity is known to the police, he operates under his “Incognito” alias and refuses to be photographed without a mask. Local television and print reporters cover his exploits without revealing his identity.

In Bristol, where most of POPSquad’s stings are conducted, the police and local government walk a fine line, using POPSquad’s work without officially supporting his tactics.

“As a community, we understand that parents and families are hypersensitive to predatory behaviors and keeping their kids safe,” Bristol Mayor Ellen Zoppo-Sassu said in a statement. “Our Police Department has an active Criminal Investigation Unit that has many active cases of their own, and also have received leads from POPSquad which we pursue as well."

Erdmann said he feels Bristol police don’t appreciate his talent or his results.

“Nobody out here does it. And the ones who are doing it, aren’t doing it right. Even the cops,” Erdmann said. “In this field, sex crimes, no one can hold a candle to me. And that’s a problem.”

Referring to Erdmann, Bristol Police Lt. Richard Guerrera told NBC News: “We don’t have a working relationship with him. We don’t advise him, he doesn’t call us, he does his thing and if a report is made, we investigate it.”

Things don’t always go smoothly. In August 2017, a man who allegedly came to a Planet Fitness parking lot at midnight to meet a 14-year-old girl found Erdmann instead. When the target, Jordan Malmstrom, 33, realized Erdmann was filming, he attacked, according to a police report of the incident. Police wrote that Malmstrom punched Erdmann repeatedly and stole his camera. As Malmstrom sped away, his car clipped Erdmann’s leg.

Malmstrom was arrested in February and charged with assault, larceny and enticing a minor. He pleaded not guilty. At a December hearing, a prosecutor told the judge the state was no longer willing to pursue the case, and the charges were dropped. Malmstrom’s lawyer, David Kamins, told NBC News that the state noted in remarks to the judge that Erdmann had been uncooperative. The state's attorney declined to comment on the case.

‘THERE’S GOING TO BE SOMEONE WHO GETS HURT’

Beyond Bristol, groups like POPSquad have met resistance from law enforcement agencies concerned that untrained civilians — many with criminal records of their own, like Erdmann — are confronting targets in stings that may threaten public safety and have unintended consequences.

"It’s detrimental to what we're trying to do,” said David Frattare, Ohio’s director of state investigations for the Internet Crimes Against Children Task Force, a national group of federal, state and local law enforcement agencies that investigate online child sexual exploitation. “We spend an inordinate amount of effort to train officers to conduct these investigations in a secure and safe way that will maintain the evidence and end in prosecution."

In the past six months, Frattare said he has seen a "resurgence" in online child-predator hunting groups not seen since the early 2000s. These online vigilantes, who often show up in police-style gear and use language that gives the false impression that they are members of law enforcement, have been a topic of conversation at meetings with the other 60 commanders who lead the national program.

"They're seeing these groups spring up in their areas,” said Frattare, who advises local law enforcement to discourage the vigilantes. “We've tried to let them know some of the dangers they're facing by going out and putting themselves in harm’s way. They aren't trained."

"Sooner or later there's going to be someone who gets hurt," Frattare added.

Erdmann says he’s not concerned about his own safety, or the safety of the people he targets. This month, his probation on the drug conviction ends and he says he’ll likely leave Connecticut for bigger things: international stings, seminars across the country, and if all goes well, a POPSquad television show. He signed a contract earlier this year with a reality show development agency, Smartmonkey Productions, but no one’s bitten yet.

For now, his audience is online.

“It’s a cult following,” Erdmann said. “There’s two types of people who don’t like POPSquad: We either caught you or you know somebody that we caught.”