RICHMOND, Va. » Richmond police say they have detained a teenage boy suspected of assaulting a young girl and killing her little brother.

Police spokeswoman Dionne Waugh said the teenager was being medically evaluated Friday, and police planned to charge him in the attacks.

Officials on Friday identified the deceased boy as 8-year-old Martin Cobb.

Neighbors told the Richmond Times-Dispatch that the boy died trying to protect his sister from the attacker. Neighbor Sudan Aunu said the girl is alive today because of her brother.

Pastor Theodore Hughey of the Abundant Life Church said the siblings were inseparable and always in and out of the church. He said the girl is 12.