Dudley Davey, 35, pleaded guilty to both the rape and murder of the 56-year-old who was found buried in a shallow grave three days after she went missing from her home in Fregon, in SA's north, in March last year.

South Australian Supreme Court Justice Ann Vanstone jailed Davey for life on Thursday and set a non-parole period of 32 years.

"This was a cold-blooded killing of a woman who had worked with skill and compassion in your community," the judge told Davey.

Justice Vanstone said the drug addict and serial offender had chosen Mrs Woodford as an "easy target, vulnerable because of her empathy".

She said Davey's offending was "callous in the extreme" and at the higher end of the scale for the crimes of rape and murder.

Outside court, Mrs Woodford's husband Keith said he hoped Davey would never be paroled.

"Dudley Davey should never ever be let out of jail for the shocking crime he committed," Mr Woodford said.

"We will always mourn Gayle but so many people have helped us to cope the with the tragedy of her death."

Justice Vanstone said Davey had gone to Mrs Woodford's home in Fregon with the intention of enticing her outside so he could rape her and "that's what you did".

She said he then decided to kill her in the hope of covering up the rape and theft of the ambulance Mrs Woodford used in her work at the Fregon health clinic.

A post-mortem examination found that the much-loved nurse suffered multiple wounds, including blunt force trauma to the brain, and the final blows Davey inflicted were to stomp twice on the back of her neck.

Mrs Woodford had lived and worked in Fregon for five years, and community leaders told the court that Davey would never be welcome back on SA's indigenous lands.

They said the crime had cast a "dark cloud" over the lands.

AAP