Overview
On May 31, 2014, in Waukesha, Wisconsin, United States, two 12-year-old girls, Anissa Weier and Morgan Geyser, lured their friend Payton Leutner into a forest and stabbed her 19 times in an attempt to appease the fictional character Slender Man. Leutner crawled to a road where she was found, and recovered after six days in the hospital. Weier and Geyser were found not guilty by mental disease or defect and committed to mental health institutions for sentences of 25 years to life and 40 years to life, respectively. After seven years, Weier was granted early release and will be under supervision until age 37.
Background
Slender Man is a fictional entity created on the Something Awful online forums for a 2009 Photoshop paranormal image contest. The Slender Man myths were later expanded by other people, who created fan fiction and artistic depictions of the entity.
Slender Man is a tall, thin character, with a featureless white face and head. He is depicted as wearing a black suit, and is sometimes shown with tentacles growing out of his back. According to the Slender Man myths, the entity can cause amnesia, bouts of coughing, and paranoid behavior in individuals. He is often depicted hiding in forests.
From Wikipedia (CC BY-SA 4.0).