The teen has been charged with first-degree murder in the killings of Donta Parker, 16, and his friend Sakinah Reed, 17, as well the shooting of another 16-year-old boy who was shot in the hand. The three were wounded in a shooting near 76th Street and Dorchester Avenue about 3:35 p.m. Jan. 5.
Police did not specify what the boy's role in the shooting was.
The three teens were walking in the area when someone in a passing gray Ford Explorer fired at them, police said at the time.
Parker was shot in the head and Reed was shot in the chest. Both were pronounced dead at Advocate Christ Medical Center in Oak Lawn an hour after the shooting, according to the Cook County medical examiner's office.
Parker lived in the 7800 block of South Cregier Avenue, and Reed lived in the 9000 block of South Burley Avenue, according to the medical examiner's office.
A third boy, 16, was shot in the finger and ankle and was taken in good condition to St. Bernard Hospital and Healthcare Center, where he was treated and released.
The three teens were among at least 10 people shot across Chicago during a nearly 14-hour stretch starting about 6:45 a.m. Jan 5, and more than 125 people shot since Jan. 1.