Slender Man stabbing: Teen sentenced to more than 20 years in mental institution for attack

MICHIGAN -- (WXYZ) -- One of the two attackers who stabbed a friend at the request of a fictional character has been sentenced to 25 years in a mental institution.

Anissa Weier, one of the two teens involved in the "Slender Man stabbings," pleaded guilty in August to being a party to attempted second-degree intentional homicide, but she claimed she wasn't responsible for her actions because she was mentally ill. In September, a jury agreed.

Waukesha County Circuit Judge Michael Bohren on Thursday sentenced the 16-year-old Weier to be hospitalized for 25 years from the date of the crime, which would keep her institutionalized until age 37.

Weier apologized in brief comments in court and said she accepted responsibility.

Payton Leutner survived 19 stab wounds in a Waukesha, Wisconsin park in 2014. Leutner, Weier and the other girl charged in the stabbing, Morgan Geyser, were all 12 years old at the time.

Both Weier and Geyser told detectives they felt they had to kill 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 apologized in brief comments before her sentencing.

"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," Weier told the judge, as she sat next to her attorney. "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's mother, Stacie Leutner, sent the judge a letter this week in which she wrote that the trauma of the attack "has defined our lives" and that her daughter still fears for her life. For months, Payton slept with scissors under her pillow for protection, and she still keeps her bedroom windows closed and locked.