Ken Miller, the police chief of Greenville, South Carolina, was being strangely literal during a press conference earlier this month when he stated, “The clowning around needs to stop.” The summer of 2016 had seen a rash of mysterious clown sightings, beginning in South Carolina and then spreading to North Carolina, Georgia, and Alabama. In the reported instances, children said they saw figures dressed as clowns attempting to lure them into the woods or other isolated situations. No one had been arrested, but no one had actually been kidnapped either. Sounds like the setup for a horror movie, right?

But this is far from the first time a wave of “phantom clowns” has happened in America. In 1981, Loren Coleman, a social worker and the director of the International Cryptozoology Museum, noticed similar sightings in the Boston area and coined the term. He went on to write Mysterious America in 1983, a book in which he devoted a chapter to discussing the phenomenon of phantom clowns. Coleman is now considered an authority on the subject. At the time of the ’81 sightings, he was working for the Massachusetts Department of Social Services working on cases of abused and neglected children, so he remembers being acutely aware of the involvement of kids in the reports. “There were two reports of grade school children seeing clowns and supposedly being enticed to come into vans,” he says. “There were no reports of arrest, no adult sightings, and no kids that were actually abducted.”

Coleman began reaching out to people across the country to determine whether similar incidents were happening elsewhere. He estimates he sent 400 letters to people requesting any information. Reports came back from Cleveland, Kansas City, and Denver. “Most often I found that it was in local newspapers that things like this were being reported.” says Coleman. “They didn’t become national stories, they became local stories.”

The way that these initial sightings were covered is significantly different from the sightings this summer, which have garnered plenty of national coverage. Coleman can’t explain what caused the phantom sightings back then. “It was almost as if there was something in the ether,” he says. But he doesn’t necessarily think these sightings are imagined either. He believes that the copycat effect is at play in this current crop. Coleman points to the broader awareness of the story and the way the sightings spread out from a central point. “It’s almost as if somebody dropped a rock in a pond,” he says.

It’s worth pointing out that the 1981 wave predated Stephen King’s book It, which was released in 1986 and featured Pennywise the clown, although the legend of serial killer John Wayne Gacy, who performed gigs as Pogo the Clown, had certainly already penetrated the cultural zeitgeist. Coleman maintains there isn’t a clear explanation for phantom clown sightings, but in his blog he does point out that instances of multiple sightings have occurred during the previous two presidential election cycles. He also explores the possible significance of town names in connection with the incidents. He highlights sightings that took place in Greensboro, North Carolina; Greensboro, Alabama; Greenville, South Carolina; and Green Havel, North Carolina. The findings border on conspiracy-mongering, but Coleman never alludes to any sinister plot in his observations. “I don’t let the theory get in the way of the data,” he says. He does share that, in his opinion, the sightings don’t have any kind of supernatural explanation, adding, “I see it as part of human psychology.”

For the time being, it seems like the phantom clown sightings will continue. “I’m already starting to get people from around the country emailing me or Facebook messaging me other sightings of clowns” says Coleman. But he cautions that would-be attention seekers who go out dressed as clowns hoping to scare people are playing a dangerous game. “I’m beginning to wonder if it’s going to backfire on some of these people,” he says. “They may get killed, because we’re in a very, very violent cycle this summer, and we’re not out of it yet.”