Levar T. Jones Sr., 26, was charged with unlawful possession of a firearm, two counts of endangering a child and one count of reckless conduct.
The 7-month-old boy, Levar Jones Jr., was shot in the leg and is at Comer Children's Hospital. He has been listed in stable condition and was to undergo surgery Thursday afternoon.
The shooting happened Wednesday just before 8 p.m. in the Englewood neighborhood near South Laflin and West 63rd.
The baby was shot by his 7-year-old brother. The older boy found a loaded .38-caliber revolver in a bedroom, and investigators found several other model guns in the home and are questioning the boys' father.
The Department of Children and Family Services is investigating. Chicago police say this is the third shooting in a residence this year of a child age 13 or younger.
The baby's family members say he is expected to have surgery on his leg Thursday afternoon. His grandmother said the gun in question was supposed to be in a safe place.
"It sounded like a balloon at first," said Loretha Jones, victim's grandmother, said of the shot.
"He is the best father in the world. He does everything for his children. I know this is a big mistake. I'm sorry this happened. I don't understand how this could have happened," said Loretha Jones.
Loretha Jones says most of the other guns found are model guns and that the one used was the only one loaded and was supposed to be locked up. She says her son may have had it for self defense.
"I know they have had some problems in the neighborhood," said Loretha Jones. Jones says that last week, her son was Maced and his friend stabbed in the neck by an attacker.
She says for now DCFS has custody of all five children who lived in the home with her and the rest of the family.