DUNCAN, Oklahoma (AP) — Two men and a woman were fatally shot Monday morning outside a Walmart store in southwestern Oklahoma, and the shooter is among the dead, authorities said.

Two victims were shot inside a car and the third died in the parking lot just before 10 a.m. outside the store in Duncan, Police Chief Danny Ford said.

Authorities did not immediately describe a motivation for the shooting. Ford told The Associated Press that investigators believe the gunman shot the male and female victims and then turned the gun on himself.

Stephens County District Attorney Jason Hicks authorities said during the news conference Monday afternoon that there was never an active shooter inside the store and he described the shooting as an isolated incident. He did not further explain.

Hicks said the two victims had been inside the Walmart Money Center, which offers check-cashing, money orders, tax preparation and other services, before they were killed, but that the shooter did not enter the business.

Two bodies covered with sheets were visible in the parking lot Monday afternoon. One body was in the driver’s seat of a red, two-door car. The other body was lying on the ground next to the vehicle.

Bullet holes were visible in the car’s windshield. Police said in a Facebook post that a handgun was found at the scene. At the news conference, Ford described the gun as semi-automatic but said he had no further details. He said the Oklahoma State Bureau of Investigation was still processing the scene.

Ford said he believed nine shots were fired.

Authorities have not released the identities of those killed but did confirm the shooter was among the dead. Ford said all three knew each other but declined to describe their relationships or other identifying information pending notification of immediate family.

He said all three were dead when police arrived just minutes after the shooting.

Walmart spokeswoman LeMia Jenkins initially said no staff were involved. Jenkins later released a statement offering thoughts and prayers for the family of the woman killed in the shooting, who she said had been with the company for less than two months. Jenkins said the woman was at the Walmart during her free time and wasn’t scheduled to work that day.

Duncan is a city of more than 22,000 residents located about 80 miles (130 kilometers) south of Oklahoma City. The Walmart is in a commercial center that includes a sporting goods store and a dollar store along U.S. Highway 81, the main road that passes through Duncan heading south toward Texas.

Aaron Helton, of Duncan, said he was parking outside the Walmart where he planned to buy groceries when he heard about nine gunshots.

“I arrived and there were three bodies,” Helton said.