By the Associated Press

Authorities in Oklahoma are emphasizing that the investigation into a fatal shooting outside a Walmart is preliminary, but that it was an “isolated incident.”

Stephens County District Attorney Jason Hicks said during a press conference that there was never an active shooter Monday inside the Walmart in Duncan. The shooting that left three dead, including the shooter, happened in the store parking lot.

Police Chief Danny Ford says the shooter shot a man and woman then turned then gun on himself. All three died at the scene.

Authorities are still working to notify the victim’s relatives before publicly identifying them.

Hicks says 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 Hicks said the shooter did not go inside the business.

Duncan is about 80 miles south of Oklahoma City.