"Everyone in the gang knew at that point that these guys did not shoot rival gang members, they shot officers," Chicago police Area Central Cmdr. Brendan Deenihan said of the La Raza members at a Sunday news conference. "At that point, these individuals cooperated with us and we were able to identify the driver and the shooter. We were able to arrest the driver of the van. He confessed to what he has done, and he's charged as an adult. We are still looking for the shooter at this time. It's a very active and ongoing investigation."