DENISON (AP) - Investigators are trying to determine if a North Texas man sought in the slaying of his ex-girlfriend killed himself or froze during wintry weather.

The Grayson County Sheriff's Office on Monday said autopsy results are pending on Aaron Lynn Smith.

A murder warrant was issued for Smith after Thursday night's fatal shooting of Yvonne Gauthier. She was attacked at her home near Denison, 70 miles north of Dallas.

Lt. Rickey Wheeler says Smith's body was found Friday afternoon in his pickup truck in Cartwright, Okla. Wheeler says investigators believe Smith died from a mixture of pills and alcohol, or he froze to death, or a combination. A rifle was recovered from the truck.

Smith's body was discovered when officers in Bryan County, Okla., checked a report of a suspicious vehicle.

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