A 55-year-old woman has been arrested on suspicion of attempting to murder her 82-year-old mother after taking her from a care facility in Gunma Prefecture.
According to police, Hiroyo Tabei is accused of taking her mother, Toshiko, on June 19 by car to a riverbank in Maebashi City and causing her to suffer respiratory distress by an unknown method.
Tabei's younger sister called 110, saying her older sister was taking their mother to the area under Takebashi Bridge. When officers arrived, they found both women collapsed and unconscious. Toshiko later died in hospital.
Tabei was arrested on Friday after discharge from hospital and is being questioned about the events on the riverbank.