One of the perpetrators involved in the notorious 2014 Slender Man stabbing incident has gone missing after removing her ankle monitor and escaping from her group home in Wisconsin.

According to officials, 23-year-old Morgan Geyser absconded from a facility in Madison on Saturday night.

She was last observed in the company of an adult associate, and as of Sunday morning, her location remains undisclosed.

Earlier this year, Geyser was conditionally released from a mental health institution and relocated to the group home as part of her rehabilitation.

Over a decade ago, Geyser, alongside Anissa Weier, enticed their friend Peyton Leutner into the woods of Waukesha during a sleepover and brutally stabbed her 19 times. The girls were each 12 years old at the time of the attack.

During this horrifying incident, Geyser executed the stabbing while Weier encouraged the merciless act of aggression.

The sinister duo then abandoned Leutner – leaving her to die – but she miraculously survived. She managed to crawl out of the woods, where a cyclist found her. 

Weier and Geyser had conspired for months to slaughter Leutner in the name of the fictional horror character Slender Man. 

Morgan Geyser, pictured at age 12, stabbed her friend 19 times as a sacrifice to Slender Man 

Peyton Leutner, pictured as a child, miraculously crawled her way out of the woods and survived

They were charged in adult court with first-degree attempted intentional homicide.

Weier had pleaded guilty to the lesser charge of attempted second-degree intentional homicide as a party to a crime, but the jury found her to be not guilty by mental disease or defect in 2017.

She was sentenced to 25 years in a mental hospital but was granted release in 2021 after agreeing to live with her father and to wear a GPS monitor.

Geyser, who has schizophrenia, pleaded guilty to first-degree murder, but as part of her plea deal, was convicted but found not guilty by reason of mental disease or defect in 2018. 

Waukesha County Circuit Judge Michael Bohren, who has since retired, had committed her to a psychiatric hospital for 40 years – a sentence she only served about 25 percent of.  

In January, Bohren said Geyser could be released after three experts testified that she was making progress battling her mental illness. 

During the same hearing, Geyser also came out as transgender, but female pronouns have continued to be used for court consistency, Dr Brooke Lundbohm, who psych evaluated Geyser, explained.  

At the time, Dr Kenneth Robbins claimed that Geyser no longer had psychosis symptoms that experts agreed played a significant role in the violent assault she committed.

Police shared a photo of Geyser, capture by a security camera, from earlier this month 

Geyser appeared in court in January, when a judge ruled that she could be released if three experts testified that she was making progress in her battle against mental illness

Lundbohm’s treatment team came to the same conclusion. 

When the judge asked Robbins if Geyser was ‘faking’ her psychotic symptoms back in 2014 when the stabbing occurred, he quickly responded ‘no.’

‘I think either she was experiencing transient psychotic symptoms, which is to say psychotic symptoms that didn’t persist and gradually went away,’ Robbins explained. 

‘Or the intensity of her fantasies based on some of the trauma she had experienced were so intense that she believed them to be true.’

The trauma Robbins was referring to was Geyser’s claims of sexual abuse by her father, who died in 2023.

Geyser’s father had also reportedly been diagnosed with schizophrenia, Stacie Leutner told ABC.  

Geyser’s symptoms more closely align with post traumatic stress disorder, anxiety and autism, Robbins added.

While Bohren agreed to Geyser’s release – effectively slashing her sentence by about three decades – the original plan had to be reworked. 

In March, prosecutors rejected the proposal to integrate Geyser back into society after Leutner’s mother, Stacie, expressed concern that Geyser’s group home was set to be just eight miles away from her daughter.