A 13-year-old boy found dead on a riverbank in Kawasaki who may have been the victim of bullying was killed with multiple sharp objects, investigative sources said Tuesday, noting the victim had sustained a deep stab wound to the neck.

A friend said Ryota Uemura had revealed that he had been abused by a group of older boys who may have tried to kill him.

The victim started to get involved with the group in November. He was worried about the escalating violence after he said he wanted to leave the group, the friend said. Uemura was quoted as saying that he wanted to go to school but was threatened into not attending. Uemura told the friend the violence against him began when he refused to shoplift after being ordered to do so. Other friends had witnessed Uemura, his face swollen, being accompanied by the group earlier this month.

According to the sources, a broken box-cutter blade was found not far from the body of Uemura, but the wound was too deep to have been made by a cutter blade. Kawasaki Prefectural Police investigators are hoping the shape of the wound will help them determine the weapon used to inflict it.

The cause of Uemura’s death was hemorrhagic shock. The cutter blade on the riverbank was stained with blood, and there was a pool of blood nearby. The body had multiple sharp stab wounds on the neck.

The investigative sources also said Uemura’s hands may have been bound when he was killed. His hands did not appear to have any defensive wounds as would usually be found if he had tried to protect himself from an attack. Cut-off cable ties, which often bind baggage and cables, were also found near the body.

It is also possible that Uemura was held down by someone and unable to fight back.

Security camera footage near the place where Uemura’s corpse was found shows people about the same age as the victim walking toward the river with him and later coming back without him.

KEYWORDS murder, Kawasaki