Deandre Binion, 25, faces three counts of first-degree attempted murder and one count of aggravated battery by discharging a firearm, Chicago Police Department Chief of Detectives Brendan Deenihan said.
He was taken into police custody Tuesday. The toddler was shot in the head on April 6 as he was riding in a vehicle with his grandmother and her boyfriend, police said. Binion was in a separate vehicle.
Both cars were traveling on Lake Shore Drive near Grant Park when one vehicle wouldn't let the other into a lane.
Binion allegedly pulled out a weapon and opened fire, with one of the bullets going through a rear passenger window and striking the child in the head. The weapon was recovered.
"She didn’t know the defendant. Like I said, this was road rage," Deenihan said. "She gave us a great description, so we were able to put him in a photo array and she eventually picked him out."
Surveillance video was used to track Binion's vehicle but investigators discovered the car wasn't registered to him., Deenihan said.
Jushawn Brown, 43, who police said was driving the vehicle with the child inside, was arrested and charged earlier this month with unlawful use of a firearm by a felon in connection to the shooting. Deenihan said a loaded gun was found in the car but did not appear to have been fired.
The child is currently hospitalized in serious condition, officials said. On Monday, doctors said he was breathing on his own and that they are "optimistic for his continued recovery," WGN-TV reported.
"We are thrilled to report this very good outcome after such a serious head injury," they said. "He continues on a very positive trajectory, and I expect him to have a great road ahead."