WAUKESHA - Anissa Weier, one of the two Waukesha girls charged in the 2014 Slender Man stabbing, pleaded guilty Monday to a reduced charge and will proceed to trial only on whether her mental condition at the time should make her legally responsible for the crime.

Weier's attorney and prosecutors announced the resolution Monday morning at a status conference ahead of her trial, which is scheduled to begin next month. Waukesha County Assistant District Attorney Ted Szczupakiewicz said the family of the victim, Payton Leutner, supports the plea arrangement.

Her co-defendant, Morgan Geyser, appeared at a separate status conference Monday after which the prosecutor and her attorney suggested a plea deal to avoid trial is still a strong possibility in her case, as well.

Both girls, who were 12 at the time of the attack, are charged as adults, and each has entered an insanity plea. Each told detectives they were acting to appease or impress Slender Man, an internet boogeyman the girls said they believed would harm them or their families if they didn't kill Leutner.

Weier, now 15, pleaded guilty to attempted second-degree homicide, as a party to a crime, with use of a deadly weapon. She has been held at a juvenile detention center in West Bend since her arrest May 31, 2014.

If a jury finds her not guilty by reason of mental disease or defect, she agrees she would not seek conditional release from a state mental hospital until July 2020.

If the jury rejects the insanity defense, prosecutors agree to recommend a sentence of 10 years in prison, plus 10 years of extended supervision. Weier faced a possible maximum prison sentence of 45 years in prison, plus 20 years of extended supervision if convicted of attempted first-degree intentional homicide. Under the reduced charge, the judge could ignore the sentencing recommendation and impose a maximum of 25 years in prison and 10 years under supervision.

The possibility of second-degree homicide was first raised by the defense at the preliminary hearing stage of the case, when it was suggested that the girls acted intentionally but out of the belief it was necessary to save their own families from Slender Man. If the defense had convinced the judge that was the proper charge, it would have been refiled in juvenile court. The judge, and later the Court of Appeals, declined to transfer the prosecution out of adult court.

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For the first time since her arrest more than three years ago, Weier, now a much more mature looking and sounding teenager, spoke at some length in court. She had to explain to Waukesha County Circuit Judge Michael Bohren that she understood what she had done and the consequences of pleading guilty to the new charge.

For the most part, Weier repeated the explanations she offered to a detective the day of her arrest. But for the first time, she said she feared not only that Slender Man would harm her and her family if she didn't kill her classmate, but that she feared Geyser, her co-defendant, would return to Waukesha and kill her if Weier didn't try to flee with her after the actual stabbing occurred.

Weier also at first declined to mention her victim by name.

"I’ve put her through enough judge, I don’t feel like saying her name."

But after Bohren explained it was a necessary part of determining whether she was making her plea freely, voluntarily and intelligently, Weier referred to Leutner by her first name a few times.

Later Monday, a heavily medicated Geyser also appeared in court as lawyers and Bohren set dates to discuss jury instructions and selection prior to her scheduled trial in October.

But afterward, both sides made it clear they are still talking about a possible plea deal as well.

"We're still talking," Szczupakiewicz, the prosecutor, said.

Geyser's attorney, Anthony Cotton, said, "I really don't think there's a whole lot we're fighting over in this case," suggesting that if the state would not contest the mental plea, Geyser would plead guilty to the substance of the crime. He expects there's common ground that he hopes could result in a plea to both the facts and to Geyser being found not guilty by reason of mental disease or defect.

Geyser, diagnosed with early-onset schizophrenia, has been in custody and receiving treatment at a state mental hospital for over a year, under a civil commitment order by a different judge. Mental health experts have agreed she meets the standards for the so-called NGI plea.

Cotton said he doesn't think Geyser would agree to even the NGI finding, if it came with a requirement that she serve a set time in the hospital, saying it really should be up to the treating doctors and Bohren to decide when Geyser is ready for conditional release in the community.

Earlier, Bohren had ordered that juries for each girl's trial would be sequestered, an expensive precaution against outside information having an influence on the outcome.

The case has drawn international publicity after the girls' arrests near I-94 hours after Luetner was found bleeding in a park by a passing bicyclist. She had been stabbed 19 times during a game of hide-and-seek after a birthday sleepover at Geyser's house the night before. The defendants told police they were trying to walk to Nicolet National Forest, hundreds of miles away, where they believed Slender Man lived in a mansion.