One of the girls, now 18, cried as she recounted how she approached the unsuspecting victim in the 2900 block of West Altgeld Street as she was getting into her car.

"When I splashed her the first time, it was in her chest," testified the teen, her head down and hair covering her eyes as she sat in shackles on the witness stand at the Cook County Criminal Courts Building. "She grabbed her hands and covered her face."

After her accomplice, a 15-year-old boy, hit Medina in the back with a baseball bat, she said, "I splashed (more acid) on her back. … She was screaming. She was screaming so much."