A 13-year-old in Queens is facing assault charges after stabbing his 14-year-old sister multiple times inside their home Saturday night, the New York Post reported.

Investigators say that during an argument between the two, the unnamed 13-year-old stabbed his sister with a steak knife, and then called 911 to report “somebody with a knife breaking into the house.” Despite suffering wounds to her back, legs, thighs, arms, and face, the victim was able to point to her brother as the attacker.

Rupiah Begum, the mother of the teenagers, is distraught about what has occurred. The mother of five says she was at work, five minutes away from the house, when she received a call that her son had attacked her daughter. Her husband, and the children’ father, was away on a trip to Bangladesh.

“I don’t know what happened,” Begum told The Post in an interview. “Everything is good usually. They play together. No problems usually.”

Begum says that immediately following the incident, the young suspect called her, stating that something was wrong and that he was angry. The reasoning for the attack remains unclear, but investigators were told by the child that the stabbing was the result of her “bothering him.” No additional information has been released.

“He screams a lot and there’s, you know, there’s a lot of yelling,” one of their neighbors explained. “They came here three years ago. Nicest neighbors we ever had. Never any trouble at all.”

The victim is alive, but is in critical conditions. She is currently being treated at Jamaica Hospital, while her brother and attacker remains in police custody.