Rodney Lawrence has pleaded guilty to accessory after the fact to murder in relation to the brutal stabbing death of Elizabeth "Betty" Dixon, whose body was found at Ashtonfield in 1982.
Lawrence, now 66, who was due to face the first day of a murder trial in Newcastle Supreme Court on Monday, was re-arraigned and pleaded guilty to accessory after the fact to murder.
Crown prosecutor Brad Hughes SC told Justice Ian Harrison the prosecution would not be proceeding on the murder charge.
The man who the prosecution say committed the murder has since died and can not be identified.
Lawrence kept what he knew about the murder secret for decades and once he was charged always maintained he was involved, but wasn't responsible for killing Ms Dixon.
Ms Dixon, 31, who was from Northern Ireland, had been tied up, suffered 27 stab wounds and head injuries consistent with being struck with a blunt object.
Her body was found in her car in bushland at Ashtonfield on April 6, 1982.
After initially being refused bail after his arrest, Lawrence was granted Supreme Court bail in April this year.
Despite his guilty plea on Monday, Lawrence's bail was continued on Monday.
He will face a sentence hearing in Newcastle Supreme Court on December 6.