Police say a 7-year-old boy fatally shot himself in his suburban Minneapolis home after a loaded handgun was found in a box containing a toy, the AP reports. Police were called to a townhome apartment complex in Plymouth around 3pm Wednesday on a report of a child bleeding from the head. When officers arrived they discovered Keyaris Samuels with a gunshot wound. Police said Thursday that the boy and his siblings were home alone when the gun was discovered in a box containing a hoverboard. The three other children were outside when Keyaris accidentally shot himself. The boy's mother came home shortly afterward. Plymouth Police Chief Michael Goldstein says the boy's mother told police she doesn't know the source of the gun. Police are investigating and want to hold the gun owner responsible. (More shooting stories.)