WISCONSIN police in the United States have released grisly crime scene photos from the so-called “Slender Man” stabbing case, showing the 12-year-old victim’s blood-soaked clothes — and the steak knife used in the attack.

Sixth-grader Payton Leutner was wearing yellow jeans and a white shirt printed with a heart and the words “Love, Hope, Smile, Beautiful, Dream,” when her deranged classmates Morgan Geyser and Anissa Weier attacked her in the woods to please a fictional demon called “Slender Man.”

Holes in the victim’s clothing, from some of the 19 stab wounds are visible in the photos, released by the Waukesha Police Department.

The images were unsealed because the teens are now serving a combined 65 years in a mental hospital for the 2014 stabbing.

One photo showed the backpack the attackers brought into the woods, including the knife from Geyser’s home — alongside Kudos cereal bars and notebooks.

Geyser, who authorities said stabbed Leutner, and Weier, who egged her on, were photographed at the police station with blood on their clothes.

Blood-splattered trees are also pictured at the scene of the attack.

The knife missed Leutner’s heart by about a centimetre. She is now in high school and is still healing.

The 25 scars across her body, are “still red and angry more than three years later,” her mother told ABC 12 in Wisconsin. “Payton has a lifetime of healing ahead of her.”