‘Slender Man stabbing’ girl sentenced to 25 years in mental hospital

One of two Wisconsin girls who tried to kill a classmate to win favour with a fictional horror character named Slender Man has been detained for 25 years in a mental hospital.

Anissa Weier, 16, pleaded guilty in August to being a party to attempted second-degree intentional homicide, but she claimed she was not responsible for her actions because she was mentally ill. In September, a jury agreed.

Waukesha County Circuit judge Michael Bohren sentenced Weier to 25 years in a psychiatric institution, retroactive to the date of the crime. That means she will be institutionalised until she is 37. This is the maximum punishment possible.

Weier and Morgan Geyser lured Payton Leutner into a wooded park in Waukesha, a Milwaukee suburb, in 2014.

Geyser stabbed Ms Leutner 19 times while Weier urged her on, according to investigators. Leutner survived after she crawled out of the woods to a path where a passing cyclist found her.

Both Weier and Geyser told detectives they felt they had to kill Ms Leutner to become Slender Man’s “proxies”, or servants, and protect their families from him. All three girls were 12 years old at the time.

Weier apologised in brief comments before her sentencing.

She told the judge: “I do hold myself accountable for this and that I will do whatever I have to do to make sure I don’t get any sort of delusion or whatever again.

“I want everybody involved to know I deeply regret everything that happened that day. I know that nothing I say is going to make this right and nothing I say is going to fix what I broke.”

Leutner family spokesman Steve Lyons said they were pleased with the sentence.

He said: “They believe that justice was served. The sentence today allows for some additional closure for Payton and her family and it also keeps both Payton, her family and the community safe.”

Prosecutor Kevin Osborne argued for the maximum 25-year confinement, which the judge granted citing ongoing concerns about Weier’s mental stability.

Weier’s attorney, Maura McMahon, argued that she should not be kept in hospital beyond her 25th birthday.

In a deal with prosecutors, Geyser, who carried out the stabbing, pleaded guilty to attempted first-degree intentional homicide with the agreement that she is not criminally responsible and should not go to prison.

She will be sentenced in February, and prosecutors have asked that she be given at least 40 years in a mental hospital.

The “Slender Man” phenomenon started with an online post in 2009, depicting a mysterious spectre whose image people edit into everyday scenes of children at play.