The boy was inside a closet playing with a gun along with two other children when witnesses heard a shot from inside the house, the Chicago Tribune reported.
The father, James Jenkins, was outside when the shooting happened and fled with the gun as soon as police arrived, according to the paper.
The boy was critically injured and rushed to Mount Sinai Hospital. By Sunday he had reportedly reached a stable condition.
Jenkins was taken into custody over the weekend after an investigation identified him as the owner of the handgun, the Tribune reported.
He was charged with a felony count of unlawful use of a weapon by a felon and possession of a weapon by a felon.
h/t DNAinfo Chicago