Anissa Weier, one of the two Wisconsin teens who tried to stab their classmate to death in a bid to curry favor with fictional horror character Slender Man, was sentenced Thursday to serve 25 years in a psychiatric institution. The sentence handed down by Judge Michael Bohren will be applied from the time of the crime, meaning Weier will be institutionalized until she is 37. “It was a planned murder by kids,” Bohren said Thursday. “We can’t forget the goal was to kill.” In 2014, Weier and Morgan Geyser brought their friend Payton Leutner, also 12, to a park and then committed the attack. Geyser herself stabbed Leutner 19 times, but she was evidently spurred on by Weier. Leutner miraculously survived the attack. “She will struggle with the events of that day and physical and emotional scars it left for the rest of her life,” Leutner’s mother wrote to the judge in a letter, noting that she believes her daughter would not feel safe if either Weier or Geyser were released into the community.