Oita Minami Police on Thursday referred Akamine Tomi, 56, an unemployed woman, to prosecutors on suspicion of murder and consensual killing over the deaths of her two daughters and her father at her home in Yufu, Oita Prefecture, in June. The referral was made with the suspect deceased, Kyodo News reported.
Investigators believe her father consented to his own killing. Police declined to give the reasoning behind that view, citing investigative information.
According to the referral, around June 21 Akamine lit charcoal she had prepared at the house in Yufu, killing her daughters Chihiro, 29, and Natsuki, 27, both unemployed, by acute carbon monoxide poisoning. She is also suspected of killing her father, Furukawa Kin'ichiro, 84, with his consent.
Akamine's own cause of death was also carbon monoxide poisoning.