Slender Man stabbing

Slender Man stabbing
Geyser (left) and Weier (right) inside a Steinhafels store shortly after the attack
Waukesha Waukesha (Wisconsin) Waukesha Waukesha (the United States) Location of Waukesha in Waukesha County, Wisconsin
Location	42.9814°N 88.2239°W / 42.9814; -88.2239 Waukesha, Wisconsin, U.S.
Date	May 31, 2014 (2014-05-31)
Target	Payton Isabella Leutner
Attack type	Attempted murder by stabbing
Weapon	Knife
Injured	1 (Payton Leutner; 19 stab wounds to the chest, diaphragm, liver, and stomach)
Perpetrators	Morgan E. Geyser and Anissa E. Weier
Motive	Belief that murdering Leutner would appease and prove the existence of the fictional character Slender Man Delusions from schizophrenia and psychosis (Geyser)
Charges	Geyser: Attempted first-degree intentional homicide Weier: Attempted second-degree intentional homicide
Criminal information
Criminal status	Geyser: Released in 2025 to mental health group home but revoked after an escape attempt Weier: Released in 2021 after 7 years
Criminal penalty	Geyser: Maximum of 40 years involuntary commitment in a mental health institution Weier: Maximum of 25 years involuntary commitment
Verdict	Not guilty by reason of insanity

On May 31, 2014, twelve-year-olds Anissa Weier and Morgan Geyser lured their friend Payton Leutner into a wooded area of Davids Park in Waukesha, Wisconsin, where they attempted to murder and sacrifice her to the Slender Man, a fictional supernatural being originating in creepypasta. Leutner suffered 19 stab wounds, but survived after being rescued by a cyclist.

Weier and Geyser stated they were motivated by their belief in the Slender Man, and believed that killing Leutner would appease him and prove his existence. They were tried as adults in 2017, and found not guilty by reason of insanity and committed to secure psychiatric facilities. Weier was sentenced to 25 years and released in 2021 to live with her father. Geyser was sentenced to 40 years and released in 2025 to live in a group home under supervision until 2058. In November 2025, Geyser cut off a monitoring bracelet and escaped the group home, only to be arrested in Posen, Illinois the next day and returned to custody.

The stabbing generated public debate about the role of the Internet in society and its effect on children, and a moral panic occurred regarding the Slender Man meme. The stabbing inspired the documentary Beware the Slenderman, the movie Mercy Black and several books. In a 2019 interview, Leutner said she was recovering and that the attack inspired her to pursue a career in medicine.