The shooter was her ex-husband, who later killed himself inside a townhouse a few miles away, police said. Authorities called the incident a murder-suicide.
The woman was shot at about 12:30 p.m. at the store located at 13460 South Route 59. She was taken to Bolingbrook Hospital, where she was pronounced dead.
Shortly afterward, police responded to a well-being check at a home on Walnut Circle a few miles away. As they approached, they heard a gunshot. The man was found inside a vehicle in the townhouse garage.
"As our officers were approaching the residence, they heard a shot ring out. Our officers retreated and set up a perimeter around the house. We called in additional assistance from Joliet and many other surrounding communities," said Chief John Konopek, of the Plainfield Police Department.
Neighbor Nick Vandenbroucke captured cellphone video of a Joliet SWAT vehicle tear down the garage door of the townhouse.