According to an incident report, Byron Crawford, 49, caught the teen cutting the wires to his vehicle in the 1400 block of Hunter Street around 12:30 p.m.
During an argument, Crawford put the teen on the ground and fired a .22 caliber handgun near his shoulder, police said.
The suspect told deputies he was attempting to scare the boy, who has threatened to kill people and burn down houses.
After the incident, the boy claimed he was going to get a .357 and kill everybody, police said.
Crawford was booked into the Richmond County Jail on charges of aggravated assault.
The relationship between the victim and suspect, who share a last name and live next door to each another, was not disclosed.