JACKSONVILLE, Fla. -- Police said a fatal shooting that took place last week on Jacksonville's northwest side was the result of two children playing Russian roulette, according to WJXT-TV.

Detectives found 16-year-old Sean Jones dead on the front porch of his friends's home in the 4200 block of Francis Road. They said Jones and a 12-year-old friend were playing with a gun belonging to the younger child's grandparents.

Police said Jones asked to hold the gun and the 12-year-old gave it to him and told him to unload it, but Jones only removed four rounds, leaving one in the cylinder, WJXT-TV reported.

The 12-year-old told police his friend said, "This is the game that me and my cousin used to play," and then spun the cylinder and closed it.

Jones put the gun in his mouth and pulled the trigger, firing one round through his head, police said.

Jones' grandfather, Freddie Sanders, said he has no idea where his grandson would have learned to play the game.

"I had no idea he knew about that game," Sanders said. "He was a nice kid. He was being good, getting ready to go to 10th grade. He had got a job."

Jones' family said they have a message for other children out of school for the summer who may be looking for something to do.

"Please, leave the guns alone. Tell their parent to put locks on them. There's too much killing going on today for young children," Sanders said.

The state attorney's office told WJXT that the case is under review and that charges are possible.

Leaving a loaded gun in the presence of minors is a third-degree felony punishable by up to five years in prison.