Chicago police say a 66-year-old man who went to his niece’s aid during a sexual assault in their home was shot and killed by the attacker.

Police say the 25-year-old attacker entered the South Side home through a window about 9 p.m. Thursday, tied up the 17-year-old girl in her bedroom and assaulted her.

Police say her uncle heard her screams and ran to her aid, and the assailant shot him in the back and the head. He died at a hospital. The girl was hospitalized.

Police say they captured the attacker after he ran from the scene and he remains in custody. His name hasn’t been released.