MADISON, Wis. (AP) — A Wisconsin woman who admitted to nearly stabbing a classmate to death in 2014 to please the online horror character Slender Man is missing after she cut off an electronic monitoring device and left a group home, authorities said Sunday.

Madison police issued an alert Sunday for Morgan Geyser, now 23, saying she was last seen around 8 p.m. Saturday with an adult acquaintance. If you see Geyser, please call 911, the alert said, adding that she had cut off a Department of Corrections monitoring bracelet.

Placed in a group home this year after being granted conditional release from the Winnebago Mental Health Institute, Geyser had been sent to the psychiatric facility in 2018 after pleading guilty to attempted first-degree intentional homicide in a deal with prosecutors to avoid prison.

Geyser’s attorney, Tony Cotton, did not immediately respond to a message left Sunday. Authorities say Geyser and her friend, Anissa Weier, lured their classmate Payton Leutner to a suburban Milwaukee park after a sleepover, where Geyser stabbed Leutner more than a dozen times while Weier encouraged her. Leutner barely survived the attack.

The girls later revealed that they believed by attacking Leutner, they would gain the privilege of serving the Slender Man and feared for their families' safety if they failed to comply.

The Slender Man character was created online by Eric Knudson in 2009 and quickly ascended to notoriety, becoming a central figure in various media, including video games and a 2018 film.

Weier also pleaded guilty to attempted second-degree intentional homicide and was sent to a psychiatric center, being granted release in 2021.