A CAIRNS man once described as a "champion mate" has admitted he brutally raped and murdered 81-year-old grandmother Maria Ball almost four years ago.

Raymond Kamuai Cory, 24, yesterday pleaded guilty to two charges of rape and one of murder in the Cairns Supreme Court after previously indicating he would take the case to trial.

He attacked Ms Ball on May 24, 2009, as she walked along Kamerunga Rd to Rusty's Markets in the early hours of the morning. Ms Ball was found unconscious and later died in hospital.

Cory was indicted on the charges yesterday and solemnly entered guilty pleas to each one via video link from prison.

He will be brought to Cairns on May 13 to be sentenced by Justice David North.

A mandatory period of life in prison is expected to be handed down.

Crown prosecutor Michael Byrne SC said Ms Ball's family resided in Brisbane and would not travel to Cairns for the sentence as the victim's granddaughter had a three-week-old baby.

Justice North consented to a video link being set up in the Brisbane office of the Director of Public Prosecutions for the sentencing.

"It would not be for a public forum," Mr Byrne said.

Cairns Justice Jim Henry previously indicated he could not hear the matter due to a conflict of interest. Justice North is Townsville-based.

Ms Ball was a well-known figure at Rusty's Markets, where she had a stall, and she was also a charity worker with Lifeline. She was described as a "dynamo", and hundreds of people attended her funeral.

A committal hearing in 2011 heard Cory was a "champion mate" who changed into a person his friends hardly recognised after a drunken accident left him in a Brisbane burns ward for months.

The Whitfield man was studying horticulture at TAFE and had attended a nearby party with friends prior to the bashing.

Cory was arrested in the weeks following Ms Ball's death after a city-wide manhunt, and has undertaken a number of psychiatric tests in the years since, but was found mentally fit to face court.

The Cairns Post