Police in Oita have arrested a 40-year-old woman over the death of her 7-year-old son.
According to police, the woman, identified as Noriko Okada, killed her son Koki sometime between midnight and 2 a.m. on Friday. NTV reported that Okada's husband called 119, saying that Koki was unconscious and bleeding from the mouth.
When an ambulance arrived, Koki was in a state of cardiopulmonary arrest. He was confirmed dead shortly after at a hospital.
Police said there were strangulation marks on the boy's neck and that Okada had admitted to killing her son, but has so far given no motive.
Okada and her husband have two other children -- a daughter, 17, and a son, 6.
Police said Okada had been institutionalized several years ago and that her family reported that her behavior had started becoming erratic about two months ago, according to NTV.© Japan Today