Boy, 5, accidentally shoots and kills sister, 2, with rifle, Ky. police say

(CBS/AP) BURKESVILLE, Ky. - A 5-year-old Kentucky boy accidentally shot and killed his 2-year-old sister Tuesday while playing with a rifle that police say he received as a gift, reports CBS affiliate WKYT. 

Their mother had reportedly stepped outside just minutes before the incident.

Doctors reportedly worked for an hour to revive 2-year-old Caroline Sparks, but were unsuccessful, reports the station.

The boy shot the girl by accident with his .22-caliber rifle, officials said. A said the boy is used to shooting with his father on their property. The rifle was reportedly kept in a corner and the family didn't realize the gun was loaded.

According to police, the mother was cleaning the house and she had just stepped out on the porch when she heard the weapon go off. 

 An autopsy is scheduled for Wednesday.