A customer fatally shot an armed robber at an auto parts store last week in south suburban Dolton.

About 8 p.m. Sept. 13, 20-year-old Jonathon Agins went into Advanced Auto Parts in the 800 block of East Sibley Boulevard, wearing a mask and armed with a gun, according to Dolton Police Chief Robert Collins Jr.

After demanding money, Agins fired his weapon at two of the store’s employees, Collins said. A customer left the store while Agins was distracted.

The customer, a concealed carry permit holder, took cover behind a vehicle in the parking lot after hearing the shots, Collins said. As Agins ran out of the store, still armed with a gun, the customer fired his weapon, striking Agins in the abdomen.

Agins, a Calumet City resident, was initially taken to St. Margaret’s Hospital, but was transferred to Christ Medical Center in Oak Lawn. He died there at 2:29 a.m. Sept. 14, according to the Cook County medical examiner’s office.

The customer who shot Agins was taken to Ingalls Memorial Hospital in Harvey to be checked out because he was “a little shaken up,” Collins said.

The investigation into the shooting is ongoing, Collins said.