A 3-year-old St. Louis County boy is expected to recover after being accidentally shot by his 4-year-old brother.

The shooting happened Sunday afternoon at the family's home in north St. Louis County. Police say the boys' 27-year-old father was taken into custody. Formal charges have not been filed.

The 3-year-old was taken to a hospital with what was described as a graze wound.

Police have not said how the 4-year-old got his hands on the gun. Police confiscated the weapon.