DENISON, Texas (AP) -

Investigators are trying to determine if a North Texas man sought in the killing of his ex-girlfriend took his own life or froze during wintry weather.

The Grayson County Sheriff's Office on Monday said autopsy results are pending on 53-year-old Arron Lynn Smith.

Smith was sought on a murder warrant following Thursday night's death of Yvonne Gauthier. She was shot while at her home near Denison, 70 miles north of Dallas.

Lt. Rickey Wheeler said Smith's body was found Friday afternoon in his pickup truck in Cartwright, Okla. Wheeler said investigators believe Smith died from a mixture of pills and alcohol, or he froze to death, or a combination of those factors.
    
Smith's body was discovered when officers in Bryan County, Okla., checked a report of a suspicious truck.