Bond was set at $1.5 million for a Chicago man charged with murder in the death of an 18-year-old woman.
Assistant Cook County State's Attorney Jamie Santini says Adan Montano was acting "strange" and was harassing Stephanie Serrano and others attending a birthday party for his roommate.
The party was breaking up Monday when Montano emerged from his room wielding a butcher knife, authorities allege. Santini said Wednesday the roommate, Serrano and another woman were on the back porch when Montano attacked.
The roommate and the woman managed to escape. However, Serrano fell, and Montano stabbed her several times, at least once in the heart, authorities said.
Montano later appeared at a police district station claiming he was the victim of a battery.
It wasn't immediately known if Montano has a lawyer.