SASEBO, Nagasaki - A 16-year-old girl was sent to prosecutors Monday after she was arrested the day before on suspicion of killing a 15-year-old female classmate.
According to the police, the girl confessed that she strangled her high school classmate with a cord after hitting her several times on the head with a "tool" around 8 p.m. Saturday. The tool was not further identified.
"I did it all by myself," the police quoted the girl as saying. She did not, however, utter any words of remorse, the police added.
According to results of a postmortem on Monday, the victim died of suffocation.
The murdered girl had been decapitated and her left hand had been cut off. Police suspect the arrested girl carried out these actions after killing the victim in the apartment room in Sasebo, where the suspect lived alone.
When police entered the girl's room at about 3:20 a.m. Sunday, they found the body lying on a bed on her back but with the head and the left hand severed. The body also had several other cuts.
As there was no sign of a struggle, it is highly likely that she was attacked from behind with a tool, police said. Various tools and a bloodstained knife were found around the bed.
The two girls had been friends since middle school. The mother of the arrested girl died last autumn. The suspect began to live in the apartment by herself from April.
The victim had told her family she was going to visit the suspect's room about a week before the visit. She left her home between 2 p.m. and 3 p.m. Saturday, and reportedly spent time with the suspect in the city before going to the suspect's apartment.
At 6:40 p.m., the victim sent an e-mail to her mother saying she would be home at about 7 p.m. Her father called the police shortly after 11 p.m. when she failed to return home.
Police officers and the suspect's father went to the apartment at 3:15 a.m. Sunday. When the father questioned his daughter, the girl reportedly said she did not know anything about her classmate.
After the police found the body, the girl was taken to Sasebo Police Station for questioning. As she reportedly admitted killing the other girl, she was arrested at about 6:10 a.m. Sunday.
When the suspect will eventually be sent to a family court by prosecutors, the court will decide whether to send her to a juvenile reformatory, remand her to prosecutors or not punish her.
"We are not aware of any trouble between the two," the principal of the girls' high school said at a press conference on Sunday afternoon. "I'm really sad. We need to provide mental and emotional support for the other students."