Police have now rounded up four suspects in the Chicago mass shooting that left 13 people injured, and they also think they have a motive. Bryon Champ, 21, and Kewane Gatewood, 20, were arrested earlier; now the Chicago Tribune reports Tabari Young, 22, and Brad Jett, 22, have also been arrested and charged. Police believe Young and Champ fired into the crowd at the park, while Gatewood provided Young's weapon (a military-grade gun, perhaps an AK-47) and Jett served as lookout. Champ had been grazed by a bullet earlier that day, and went to the park with revenge in mind, say police—though a very general revenge at that..
"When Mr. Champ was shot, he believed a rival gang controlled the park and that's where they went," the police superintendent says. The gunmen "just shot into the park," not aiming at anyone in particular, he adds. Young shot off at least 16 rounds, and police are saying the fact that no one died is miraculous. Had Champ been sent to jail rather than boot camp for a 2012 weapons conviction, the superintendent says, the shooting may never have happened. "He ... was back out on the streets to be a part of this senseless shooting. That is unacceptable." More people could still be charged. Meanwhile, the youngest victim is recovering quickly. (Read more mass shootings stories.)