HOUSTON -

A family is demanding answers about why an off-duty sheriff's deputy fatally shot a woman in a Walmart parking lot.

Harris County sheriff's deputies said the loss-prevention team at the Walmart store on West Road near the North Freeway noticed several women stuffing merchandise into their purses on Thursday night.

The women paid for some smaller items and tried to leave the store with the merchandise that was not paid for, officials said.

Deputy Louis Campbell was working an approved extra job at the store. He confronted the women at the door and one of them hit him with her purse before running to a car, investigators said.

Campbell ran over to the car and told the woman who hit him to get out of the car, investigators said. She refused to get out and Campbell opened the door, officials said.

Detectives said the vehicle began to move while Campbell was between the door frame and the driver. Campbell opened fire because he was being dragged, deputies said.

The driver took off and the car was later found at The Worthington apartment complex in the 1300 block of Greens Parkway, which is about a mile away from the Walmart.

Shelly Marie Frey had been shot at the Walmart and died at the scene, investigators said.

Two children and three women, including Frey, were in the car. Frey's family wants to know why Campbell would open fire into a vehicle with children inside.

"He murdered this young lady with children in the back seat," said Crystal Muhammad of the New Black Panther Party.

"Was it necessary for him to grab the vehicle, hold on to the vehicle and shoot recklessly into the vehicle," community activist Quanell X said.

Relatives said there is no proof that Frey, who was in the passenger's seat, was involved in stealing items from the store.

Family members claim that the autopsy report indicates that Frey was shot twice in her upper extremities and chest.

The sheriff's office declined to comment, but sources told KPRC Local 2 that a single bullet from Campbell's gun traveled through Frey's body.

Frey's family said they want Campbell to be charged.

"This is a woman killed in cold blood," Quanell X said. "Whatever the perpetrator may have done, Shelley was not involved."