Maria Corona's body was found around 11 a.m. Monday by a postal worker outside the family's one-story brick home in Lewisville, which is located about 25 miles outside Dallas, authorities said.
Police arrived at the home after receiving a frantic 911 call from the mail carrier, and found a trail of blood from the body to the home, according to a search warrant affidavit. Two chain saws with blades covered in blood were found on the tailgate of a pickup truck in the driveway. One of the chain saws was still running, the affidavit said.
Police said an arrest warrant has been issued for Jose Fernando Corona, charging him with the murder of his wife.
"Witnesses in the neighborhood did hear a chain saw running, but that was all they heard," Lewisville police Capt. Kevin Deaver said. "It was an extremely gruesome scene. The method of death was brutal."
The Tarrant County Medical Examiner released autopsy results Wednesday that said Maria Corona was alive when she was decapitated. The cause of death was multiple chain saw injuries "due to assault by another person."
Jose Corona has no prior criminal history, Deaver said. Police, who declined to release the postal worker's 911 call, had never responded before to the home for any type of disturbance.
Police, noting that Jose Corona had friends and family across the state and Mexico, have asked state and federal authorities for help locating him.
He was last seen driving a gold-colored 1991 Ford Ranger pickup truck, which police said he stole from a car dealership after taking it for a test drive about three hours after the killing.
The Toyota SUV police believe Corona left his home in was found Wednesday abandoned in a parking lot in Bedford, a Fort Worth suburb. Police said they were getting a search warrant for the vehicle.