A 6-year-old Mississippi boy was found dead from a gunshot wound on Thursday in the back of a car that had been stolen from his mother hours earlier in Jackson, Miss., the authorities said.

Ebony Archie, the boy’s mother, had left him in a running Toyota Camry at about 1:15 a.m. while she ducked into a Kroger grocery store, according to Heath Hall, a spokesman for Madison County Sheriff Randy Tucker. At some point during the 10 to 15 minutes that she was gone, a Honda Civic pulled up and someone jumped out and got into the Camry, taking the car and the boy, Kingston Frazier.

Image Kingston Frazier Credit... Mississippi Highway Patrol

Ms. Archie notified a law enforcement officer at the grocery store, who began filing a report for a missing car before realizing later that Kingston had been taken, too, the authorities said at a news conference.