Former Saskatchewan resident Paul Pilipow has pleaded guilty to murdering an elderly woman in Arizona.

The body of 67-year-old Eloise Doyle was found in 1999 in the desert near Phoenix. She had been knocked unconscious, run over and set on fire.

A few days later, police arrested Pilipow and his wife Cherie in Colorado after spotting them driving the victim's motorhome.

Paul, 23, was charged with one count of first-degree murder, one count of kidnapping and one count of aggravated robbery.

His trial had been scheduled to begin Monday, but it was postponed in anticipation of his plea.

On Wednesday, he agreed to plead guilty to all charges in exchange for being spared the death penalty.

Pilipow was immediately sentenced to spend the rest of his "natural life" in prison, with no chance of parole or extradition to Canada.

The Pilipows were originally from Melville.

Last year Pilipow's wife Cherie pleaded guilty to second-degree murder in the case.

She had agreed to testify against her husband. She faces up to 22 years and will be sentenced next month.