Mothers of teens who pleaded guilty in 'Slender Man' stabbing case say there were no warning signs of violence

Anissa Weier and Morgan Geyser's moms say their daughters were "typical girls."

— -- Standing in a Wisconsin police station lobby, Angie Geyser said she was in disbelief when detectives, who had just interrogated her daughter, told her that her 12-year-old had admitted to a stabbing a classmate and leaving her for dead as part of a plot she and her friend had planned for months.

“I couldn't believe what I was hearing,” Angie Geyser told ABC News’ “20/20.” “I never would have imagined that my daughter was capable of hurting another person.”

Watch the full story on ABC News "20/20" THIS FRIDAY, FEB. 2 at 10 p.m. ET

Payton, now 15, crawled to a nearby road and was helped by a passing bicyclist before she was hospitalized with life-threatening injuries. She survived the attack.

Both girls' mothers told "20/20" that they never saw any warning signs from their daughters that they would harm someone else.

“They [Morgan and Payton] would sit up in Morgan's room and they would do each other's nails, and they would laugh, and make a mess," Angie Geyser said. "They were just typical girls.”

Morgan’s mother said she knew about her daughter’s fascination with Slender Man and talked about it with her.

“She would show us some of the pictures, and she would read us some of the stories, and while some of the subject matter was a little dark, I wasn’t concerned,” Angie Geyser said. “When I was Morgan's age, I was reading Stephen King novels. I remember being 11 years old and riding home from the library with [the book] 'IT' under my arm. And that's a very scary and dark story, so I just thought it was normal for a child of middle school age to be interested in scary stories.”

But Anissa's mother, Kristi Weier, said her daughter “never mentioned anything to me about her belief in Slender Man.”

Anissa Weier pleaded guilty last year to attempted second-degree intentional homicide, as a party to a crime, with the use of a dangerous weapon as part of a plea deal. A jury then found Weier not guilty by reason of mental disease or defect. In December a Wisconsin judge ordered Weier, now 16, to be placed under a mental health commitment for a period of 25 years, with credit for her three-and-a-half years already spent in jail. She has agreed to remain in a state mental institution for at least three years before seeking release on community supervision. If released, Weier will remain under state supervision until the year 2039, when she will be 37 years old.

Earlier this year, the court also accepted a plea deal for Morgan, now 15, who pleaded guilty to attempted first-degree intentional homicide. In accordance with the plea deal, the court also found Geyser not guilty by reason of mental disease or defect despite her earlier guilty plea. Geyser’s sentencing is set for Thursday.

On the morning of May 31, 2014, Anissa, Morgan and Payton had been over at Morgan’s house for a sleepover to celebrate her birthday. That morning, Angie Geyser said the girls had asked if they could go to the park. The first sign that something was wrong, she said, was when the police were at her front door.

“I was vacuuming in the basement and my son, who was 6 at the time, came downstairs and he told me that the police are here, and they're looking for Morgan,” Angie Geyser said. “Of course, my heart dropped down into my stomach and I went upstairs. Not only were there police in my living room, but they were wearing riot gear.”

“They asked me, ‘Where's Morgan?’ I said, ‘She's at the park with her friends,’” she said.

Angie Geyser said the police didn’t believe her and started searching the house, thinking she was hiding Morgan.

“I just kept asking ‘what happened, what's going on,’ and they wouldn't tell me other than to say there had been an incident in the park and one of the girls was hurt,” said Geyser.

When the police first reached Kristi Weier, she said they told her Anissa was missing and she feared her daughter had been abducted. As neighbors and law enforcement began looking for the girls, Kristi Weier found her daughter’s cellphone which she had left behind at Morgan’s house.

“I checked all of her text messages, trying to figure out the people that she called and contacted last,” she said. “And I went into [the] Notepad [app]… and I found, basically, her goodbye notes.”

The note from Anissa, which Kristi Weier showed to police, said, “This is my final wish to those who care, do not grieve my absence, but remember me for who I was. I love and cherish you all and wouldn’t do you harm.”

At the time, Kristi Weier still had no idea that the victim had been stabbed 19 times.

After Morgan Geyser and Anissa Weier were located, police questioned the girls separately. During their interrogation, the girls revealed they had been planning the attack on Payton for more than five months, with Morgan saying “it was necessary” to please “Slender Man.” The girls told police they had originally planned to stab Payton in Morgan’s room at the sleepover, but changed the plan to stab her in the park the next day instead.

“I get up and then Morgan hands me the knife and says, ‘I can't do it, you know where all the soft spots are,’” Anissa told police during the interrogation. “And then I give it back to her and say, ‘You do it… Go ballistic. Go crazy. Make sure she’s down’ … Morgan said, ‘I'm not doing it until you tell me to.’ I started walking away and then, like, when I was five feet away I said, ‘Now.’”

Morgan told police that is when she stabbed Payton repeatedly. Then the officer asked Morgan what she did with the knife she used.

“I put it back in the bag and walked,” Geyser told police. “I sort of wiped it off on my jacket. It was weird. I felt no remorse.”

Afterwards, police told the girls’ parents, who had been waiting in the police station lobby, what Anissa and Morgan had said.

“The interrogation is very difficult to watch because that’s not my daughter saying those things," she said. "That’s not the way she speaks. That’s not the way she acts.”

“She appears to have no remorse for what's happened, and she just talks about it in such a flat manner,” Angie Geyser continued. “That's odd for a 12-year-old child sitting in a police station with a detective, not to be frightened about what's going on.”

Weier said she had no idea her daughter had fallen so completely under the influence of Slender Man, a character many adults have never heard of. Listening to her daughter’s interrogation, she was shocked to hear Anissa speak about Slender Man and that Anissa believed in such things.

“[Anissa’s father] and I, although we were divorced, we were still very active parents. I did search her iPad. I did watch over her shoulder,” Weier said. “Anissa never talked about Slender Man to me.”

Payton had also talked to her parents about Slender Man before the attack.

“Morgan had been talking with her about Slender Man, and Payton was terrified,” Payton’s mother, Stacie Leutner, told “20/20” in 2014.

Anthony Cotton, Morgan’s attorney, said it was clear to him the moment he met Morgan that she was struggling with mental illness.

“It was apparent right out of the gate. She’d be looking around the room. She’d be looking in the corner. She seemed to be responding to things that weren’t in the room,” Cotton told “20/20.” “It was odd.”

Both the Geysers and the Weiers were allowed to see their daughters briefly before they were arrested and taken to jail.

“I remember her saying she was ‘very, very scared.’ That day plays out almost every night in my nightmares,” Kristi Weier told “20/20.” “We hugged and kissed our daughter and told her that it would be all right. We're still here for you. We'll figure this out.”

Two days after their interrogations, Morgan and Anissa were charged as adults, facing the possibility of up to 65 years in prison.

“I mean it was shocking,” Angie Geyser said.

“Seeing her in the courtroom with the jumpsuit with the shackles and the handcuffs and the belly-chain really hit me hard that my daughter did something so terrible. That was a really, really low day,” Kristi Weier said.

In the aftermath of the stabbing, investigators searched Morgan’s room and found disturbing evidence of a deteriorating young mind, which included drawings of Slender Man with children and the words, “I want to die,” and “help me escape my mind” scrawled across a page.

“Just knowing how long she was sick and suffering inside her own head before we had any idea… makes me sad,” Angie Geyser said.

As prosecutors built their case against Morgan and Anissa, the girls adjusted to life locked up and surrounded by other teenage criminals.

“In the beginning, they would make fun of her or bully her to a point of, ‘You're a psycho. You're a monster. Why did you do such a stupid, psychotic thing?’ The children just wouldn't let it go,” Kristi Weier said of her daughter Anissa’s experience.

Both girls’ mothers were making the hours-long drive to see their daughters in jail. Kristi Weier said in the last 35 months that her daughter was in jail, Anissa maybe had “40 hours of fresh air.”

“The visiting area … there’s a cement table and a piece of glass,” she said. “We can see each other, but we can’t touch her. I can’t wipe away a tear, I can’t give her a hug. I can’t kiss her.”

Kristi Weier said because all of her interactions with her daughter were recorded, she and Anissa never talked about what happened on the day of the stabbing. She said they didn’t want their conversations to be used against Anissa in court.

“We've actually, in a sad sort of way, had more of a mother-daughter bonding time than we've ever had before without the distractions of cellphones or video games or phone calls or TV. It's just her and I divided by glass talking, and she's able to open up to me and tell me what's troubling her, what's on her mind,” Kristi Weier said. “There are moments where I can't think of a happy thing when I come up here, where my heart is so full of sadness that I don't even know what to say when I get in there. That's when I put on a mask and I pretend that life is really, really good even though I'm breaking inside. I try not to show that emotion to Anissa because she needs to see me as being strong.”

“I don’t allow myself to break down in front of her and see how much this is hurting me to see her behind bars,” she added.

Angie Geyser said it has been painful to see her daughter behind glass and not being able to touch her.

“Initially, I mean, she really behaved like a caged animal. Her hair was wild,” she said of her daughter Morgan.

Angie Geyser said there were times she thought Morgan didn’t want to see her.

“The first time I went to visit her, she looked at me and she had sort of this flat expression on her face and she said, ‘Why are you here?’ It's heartbreaking,” Angie Geyser said.

While behind bars, both girls received mental health evaluations. Angie Geyer says that during an extensive psychological evaluation several months after the stabbing, Morgan received an extraordinarily rare diagnosis for such a young girl: early onset schizophrenia.

Angie Geyser said she wasn’t surprised by the diagnosis because Morgan’s father has schizophrenia. In fact, according to testimony, Morgan’s father had been hospitalized at least four times as a teenager to treat his own schizophrenia.

“When they told us what had happened and that she had done it because she believes Slender Man is real … that's where my mind went, is that she must be sick,” Angie Geyser said.

Angie Geyser later learned from Morgan that her daughter had been experiencing visual hallucinations since she was 3 years old.

“One of her hallucinations was a tall, slender, shadowy figure,” Geyser said. “And I think that’s probably what ultimately solidified her belief in Slender Man.”

When her daughter was growing up, Geyser said she did notice something when she and her husband let Morgan watch the movie, "Bambi."

"We had been concerned to show Morgan the movie because she was a sensitive and empathetic child, at least towards other people, so we were afraid that when she saw the movie, that when Bambi's mother died, she would be devastated," Geyser said. "She, in fact, had quite the opposite reaction. After Bambi's mother was shot, Morgan just said, 'run, Bambi, run!' and had no reaction whatsoever to the mother dying, so it was just kind of the opposite reaction that we'd been expecting."

For more than a year at jail, Morgan remained untreated and continued to believe she could communicate with Slender Man and Lord Voldemort from the Harry Potter book series. It wasn’t until her family successfully petitioned a judge to civilly commit her that she was moved to a mental health institution where she received medication for schizophrenia.

Angie Geyser said she saw a dramatic change in her daughter after she was able to get mental health help.

“The best way to describe it is that it was like the light came back on behind her eyes,” said Angie Geyser.

She said as hard as it may be for some to believe, she did not know how mentally ill her daughter was before the day of the stabbing.

“If I had had any idea that she believed Slender Man was real, we would have done something about it. We had no idea,” said Angie Geyser. “I think on some level, I’ll always feel responsible for not knowing that my daughter wasn’t well. As a mother, you’re supposed to be there to protect your child, and you know, I think on some level, I’ll always feel that I failed in that regard.”

She said she believes Morgan actively hid her delusions from those around her.

“I think that, as she got older, and she realized that, hey, maybe this isn't normal, that she did make a conscious effort to hide it,” Angie Geyser said. “A lot of her hallucinations were friends to her, and I don't think that she wanted to lose those friends.”

“It can go unnoticed. You know, especially with delusions. Delusions can remain compartmentalized for people. So unless you’re talking about the delusion, you may not know that it exists,” Dr. Melissa Westendorf, who was one of the court-appointed forensic psychologists who evaluated Anissa and testified at the trial, told “20/20.”

Westendorf diagnosed Anissa with a “shared psychotic disorder,” saying that Morgan’s schizophrenia coupled with both girls’ delusions about Slender Man created a perfect storm.

“Once you find this character on the internet, you can read all these stories that look real. They look like newspaper articles. It’s hard for a lot of people to differentiate … let alone a 12 year old,” Westendorf said.

Both mothers said their daughters are remorseful for what they did to Payton.

Kristi Weier worries what Anissa’s life will be like after years of being cut off from society.

“My fear is that she'll be institutionalized and she will not really know how to interact with normal people at Walmart, at the gas station, at Pick 'n Save," she said. "After spending 25 years in a mental institution with other adults, I don't know if she's going to be any better. That's my worry.”

Kristi Weier has told ABC News that she is interested in working with others on juvenile justice reform.

Angie Geyser believes her daughter is not dangerous.

“Morgan’s untreated mental illness is what made her a danger. We will know what to look for in the future,” she said. “She does not [still believe Slender Man is real]. … Morgan lives in reality now.”

“I might be naïve, but in my heart I believe she doesn't believe in Slender Man anymore. But I can't ignore the obvious that she does need therapy and she does need mental help,” Kristi Weier said of Anissa.

Angie Geyser said she hopes Morgan will be able to return home to her family, but wants the family to move away from Waukesha, Wisconsin.

“It’s difficult living in the community where you experienced the worst thing that's ever happened to you,” she said. “I frequently drive by these places that hold horrible memories. And I just want to get us all away from that.”