The Cook County Medical Examiner has identified the woman who was shot in the head and killed early Sunday morning in the Belmont Cragin neighborhood as Alexandria Burgos, 18.
The shooting happened just after midnight in the 5300 block of West Oakdale. Burgos lived in the 5200 block of North Nagle Avenue.
Police say Burgos was inside a third floor apartment when someone apparently fired shots from outside.
Neighbor Chris Harms says he heard the whole thing.
"I heard somebody screaming 'God no, God no,'" he said.
Harms says he heard seven or eight total gun shots.
Police say no one is in custody.