Lannou's son picked up the gun and it discharged, grazing the boy's thumb. The bullet went through Darren Lannou's right leg and grazed his left leg, according to the Oklahoman.
Lannou said he immediately yelled for someone to call 911. Store employees unloaded the gun, and Lannou and his son were both taken to a local hospital with non-life threatening injuries.
Lannou repeatedly apologized and said he was very upset, according to the police report.
Police Sgt. Jennifer Wardlow did not know whether they would be filing any charges.
"This will be investigated, but ultimately it will be up to the district attorney's office if any charges are filed," she told the Oklahoman. "It does appear right now to be an accident."