Anissa Weier pleads guilty to amended charge in 'Slender Man' case

WAUKESHA, Wis. -- (WITI) -- Anissa Weier, 15, pleaded guilty on Monday, August 21, to an amended charge of attempted second-degree intentional homicide, party to a crime with use of a deadly weapon in the so-called "Slender Man" case.

Anissa Weier is charged along with Morgan Geyser in the attempted murder of their then-sixth grade classmate in the spring of 2014. Investigators say the attack was an attempted sacrifice to the online character Slenderman.

Weier testified during a hearing on Monday and indicated to the court that she understood the amended charge now facing her, and that she admitted to being a party to a crime.

The court accepted Weier's guilty plea, and she was indeed found guilty of the amended charge. The court then indicated the case would move on to a second phase, where a jury would determine whether Weier is guilty by reason of mental disease or defect.

Weier initially faced a charge of attempted first-degree intentional homicide. The plea means her trial next month will look only at whether she is legally responsible for the crime or not guilty because of mental illness. She could face 10 years in prison if she's found guilty. If not, she'll spend three years in a mental hospital.

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

Geyser's attorney, Anthony Cotton, said Monday that he and his client plan to proceed to trial. He declined comment on Weier's plea, saying it would be inappropriate to do so.

Cotton said he and his team have been holding mock trials weekly.

“We have continued to gather crucial information from the focus groups we've been convening repeatedly,” he said, adding that they “are confident in our approach.”