A shooting Saturday night killed two people and critically injured a third person in Chicago's Hermosa neighborhood on the west side.
It happened during a block party near Belden and Springfield.
Police say a group of people who were not invited to the party began causing trouble.
They shot two men in their car, causing them to crash into parked cars.
A 21-year-old was fatally shot in the head, a 16-year-old died after being shot in the back, and a third person was shot in the hand.
Police say all three victims have gang affiliations.
No one is in custody for this shooting.