Denzel Pittman, of Park Forest, faces three counts of first-degree murder. Police say he was the boyfriend of the 17-year-old victim.
According to police, the victims -- Stacy Cochran-Hill, 43; and her daughters, Joi Cochran, 11; and Jade Hannah, 17 -- were each stabbed more than 20 times. Their bodies were found late Monday inside their apartment near 111th Street and Bell.
"If who the police got is the person, I hope you rot in hell. And that's putting it lightly," said Sharon Ramey, Stacy Cochran-Hill's mother.
Friends say Pittman was at the home apparently saying goodbye before reporting to a disciplinary boot camp.
Cochran-Hill would have turned 44 years old Friday.