From the cited article ...

... A woman who stabbed her sixth-grade classmate to win favor with a fictional internet character named "Slender Man" more than a decade ago left a group home where she'd been living after cutting off her monitoring bracelet, police said.

Morgan Geyser, 23, was last seen in a residential neighborhood in the west side of Madison, Wisconsin, around 8 p.m. Saturday with an adult acquaintance, and it is not known where she is, police said in a statement.

In a crime that stunned the nation, Geyser and her friend Anissa Weier, both 12 at the time of the crime, lured their classmate into a park in Waukesha, Wisconsin, in 2014, where they stabbed her 19 times to impress Slender Man, a boogeyman for the internet age.

The victim, Peyton Leutner, was also 12 at the time and survived, crawling out of the woods to safety where she was discovered by a passing bicyclist.

The trio spent a lot of time together, Leutner previously told ABC. Geyser constantly talked about Slender Man, a character that terrified Leutner, she said. ...

@#2

Wow.