The father of a 16-year-old girl who was arrested in July on suspicion of killing and dismembering a female classmate in Sasebo, Nagasaki Prefecture, asked a school official not to reveal that his daughter had beaten him with a metal bat in March, the Nagasaki prefectural board of education said in a report released Friday.
The board filed the report with the prefectural assembly's committee on education, officials said.
The school official failed to report the incident higher up the chain of command for more than a month.
The report said the high school girl beat her father with a metal bat on March 2.
The following day, her father told the school official about the incident and asked the official not to mention it to others, the report said, noting the official promised not to.
On April 24, the school official consulted with a psychiatrist who had been assessing the girl. The following day, the official filed a report with the principal, deputy principal and senior school officials on the girl's psychological condition.
The girl is alleged to have strangled a 15-year-old classmate July 26 and subsequently mutilated the corpse at the suspect's apartment in Sasebo, where she lived by herself.
She is currently in a medical facility undergoing psychological evaluation, as requested by prosecutors.