Police arrested a senior high school student Tuesday on charges of stabbing an 18-year-old classmate to death in Mie Prefecture on Monday.
The male student, also 18, admitted to stabbing his female classmate, Miu Hada, saying he was asked by the girl to kill her, the police said. The girl did not have the external injuries that normally exist when a person defends oneself, investigators said Wednesday.
According to police, Hada had said she wanted to die, prompting investigators to look into the possibility of a contract murder.
The police suspect the teenager stabbed the girl to death with a knife around 5:10 p.m. Monday on a hill in the Onoe area in Ise city. An autopsy showed that she bled to death and that there was a stab wound to her heart that was about 15 cm deep.
The students' friends were unable to contact them and they are believed to have been alone at the scene at the time of the incident, according to police.
Friends and family members rushed to the scene after the boy sent a text message to one of his friend's giving his location, but Hada was already dead when they arrived, the police said.
The police found a bloodstained knife at the scene. The male student told investigators that he brought a knife from his home.