The incident occurred on Saturday when a local police department received a call about a man with a gun at a children's playground.
When the two responding police officers arrived at the scene, they found a boy they told to show his hands. The boy allegedely reached for his belt, and one of the officers fired his gun twice, aiming at the boy's chest. The boy died in hospital after surgery.
Police shootings have got much attention after a policeman shoting an African-American in the US city of Ferguson provoked riots against police violence around the country.