At around 4:00 p.m., the boy, 19, is alleged to have repeatedly beaten the woman in the face with his hands at the residence, located in Higashi Ward. The victim was transported to a hospital in an unconscious state but died at 2:40 a.m. on Saturday.
The boy, who has been charged with assault resulting in injury, lived in the residence with his mother, sister and the victim. At the time of the incident, the boy’s mother and sister were away from the residence.
According to a neighbor, the boy and his grandmother often engaged in disputes.
Police are now investigating whether to change the charges to manslaughter.