The internet bogey man known as Slender Man has been linked to a third violent act.
On Sunday husband and wife Jerad and Amanda Miller shot and killed two Las Vegas police officers and a third person, before killing themselves.
The couple’s neighbour Krista Koch told KTNV-TV Jerad would sometimes dress up as Slender Man and the Joker from Batman, while his wife would dress as Harley Quinn.
Jerad and Amanda Miller (dressed as the Joker and Harley Quinn) opened fire on two policemen and killed a third person before turning their guns on themselves
The day before the shooting Jerad updated his Facebook status with the chilling words: “The dawn of a new day. May all of our coming sacrifices be worth it.”
The Las Vegas Review-Journal writes investigators discovered paraphernalia associated with white supremacists, including swastika symbols in the couple's apartment.
The newspaper also claims the shooters shouted “this is the start of a revolution” before opening fire and then covered the bodies of officer Alyn Beck and Igor Soldo with a cloth displaying the Gadsen or Don’t Tread On Me flag – a Revolutionary War-era symbol that has since been adopted by the Tea Party.
A neighbour claims Jerad sometimes dressed up as Slender Man
In the first instance, Anissa Weir and Morgan Geyser, both 12, are alleged to have brutally attacked their friend of the same age after a slumber party, stabbing her 19 times and leaving her in the woods in Wisconsin.
Miraculously, the unnamed victim survived and managed to crawl to a nearby road where she was found by a cyclist who raised the alarm.
Jerad Miller's final Facebook status update
And last week a Cincinnati mother told how her 13-year-old daughter stabbed her multiple times in an attack apparently planned to please Slender Man.
Shira Chess, an assistant professor at the University of Georgia who has researched Slender Man's origins told Huffington Post UK: “In terms of how can people take a fictional story so seriously, part of it is about timing.
“These girls found the story four to five years after it was created. When I first happened upon it there was relatively little online and it was easy for me to research and find the origins of the story. On the other hand, to someone coming at it many years later it may feel pervasive and enormous - it would almost appear like Slender Man was everywhere they looked online.
“Many people sort of reverse-connected the story back to old folklores from many countries, and that also makes it appear like the same story has always existed.
“This is not quite the case, of course. But when you see an old folk tale from, say Romania, that talks about a 'tall man' then it seems even more pervasive. And with that, you get some minor cracks in any theory that this is the fault of the internet. Folk tales have always existed and the Internet does not change the form - it just speeds up the tellings and retellings.”
Andrew Peck, a University of Wisconsin lecturer who also studies Slender Man and other folklore told ABC News: “It can really be who you want it to be.
“You can personalise the character and make it your own. He can be a lot of things, that’s what I think makes it so successful. That he’s mysterious and unknowable.”
He added: “He doesn’t actively murder. It’s generally more mysterious that that.
“The big thing is that he’s otherworldly, mysterious. It’s just odd that people are doing this in Slender Man’s name when part of the legend is that he’s just beyond us.”