Wilson County Deputy Daniel Fanning was hosting a family BBQ at his house, reportedly showing off his weapons to another relative, when his wife Josephine walked into a bedroom with a four-year-old, where a loaded gun was left. The child picked up the weapon, fired one round, and killed Josephine.
When local police arrived, the 48-year-old woman was already dead.
Authorities said the deputy was present at the time of the shooting and is a relative of the 4-year-old child.
"It's a sad, sad set of circumstances," said Sheriff Robert Bryan.
Bryan said Daniel Fanning was showing people his guns when the child grabbed the weapon, which Bryan said was not the deputy's service weapon.
"Nobody is immune to this - nobody. It doesn't matter if you are a law enforcement officer. These things can happen in seconds," Bryan said.