'Slender Man' stabbing girl, 15, pleads guilty, could serve ten years in prison

One of two Wisconsin girls charged with repeatedly stabbing a classmate to impress the fictitious horror character Slender Man pleaded guilty Monday, but she still faces a trial in the case next month focused on her mental health.

15-year-old Anissa Weier pleaded guilty to an amended charge of attempted of second-degree homicide as a party to a crime, with use of a deadly weapon. She initially faced a charge of attempted first-degree intentional homicide in the 2014 attack on classmate Payton Leutner, who narrowly survived the assault.

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The plea means Weier's trial next month will examine only whether she is legally responsible for the crime or not guilty because of mental illness. If she’s found guilty, she could face at least 10 years in prison. If not, she’ll spend three years in a mental hospital.

Prosecutors allege Weier and her co-defendant, Morgan Geyser, brutally stabbed Leutner 19 times in a park in Waukesha, Wi., a city west of Milwaukee. The girls, both 12 at the time, executed the attack during a sleepover. The duo then planned to walk hundreds of miles north to meet Slender Man in a forest. Leutner was able to crawl out of the woods to a path where she was found by a bicyclist.

Geyser, also due in court Monday for a status hearing, pleaded not guilty by reason of mental disease to attempted homicide charges in adult court. Weier initially entered the same plea.