Jerrell Dorsey was charged with first-degree murder and aggravated battery with a firearm for the death of Heaven Sutton, who was shot by a stray bullet while selling candy to neighbors last week, the Chicago Tribune reported.
"Bringing Heaven's shooter to justice will not bring her back, but I hope it will provide some level of solace to her family," said Mayor Rahm Emanuel.
Police said the shooting was a result of heightened tension between two local gangs.
A 19-year-old alleged member of the Mafia Insane Vice Lords, who have been fighting with the Four Corner Hustlers, was shot in the ankle at the same time as Sutton was shot, police said.
Dorsey was also charged with aggravated battery for that shooting, officials said.
Dorsey was identified by witnesses as the shooter. He was taken into custody by the Chicago Police Department's fugitive apprehension unit and the U.S. Marshals fugitive task force Friday night as he tried to flee from a building, police said.
Sutton's mother, Ashake Banks, said Saturday the arrest made her "feel a little better."
"Maybe I can get a little rest tonight," Banks said. "It's a start."