McCarthy told reporters that Endia Martin was shot with a .38-caliber handgun stolen from a car. He urged a change in the law to require gun owners to store weapons securely, saying that a firearm was brought to what would otherwise have been a "fistfight."
"There was a legal gun that became an illegal gun," he said, saying state law should be changed to require guns to be kept more securely.
"In this case, the simple fact that the law states that you can store a firearm in a vehicle is absolutely insane," McCarthy said. "Those guns need to be in lock boxes, in safes, in people’s residences or on their person.”
The alleged killer, who is also 14, was charged as a juvenile with homicide Tuesday. Her uncle, 24, and another teenager, a 17-year-old boy, have also been charged in connection with the killing.
Investigators said that Endia was shot Monday afternoon as she walked home from Tilden Career Community Academy. Kent Kennedy, Endia's stepfather, said she and her alleged killer had been fighting on Facebook.
"They had words and she gunned our daughter down. For what? What reason would another girl gun down another child? It's senseless," he told the Chicago Tribune. "Kids are dying so young nowadays. It's senseless. Parents shouldn't have to bury no child."
Notable deaths of 2014 [PHOTOS]