A jury ought to have concluded the Norfolk Island murder confession by Glenn McNeill was unreliable, appeal judges have been told.
McNeill, a 29-year-old New Zealand-born chef sentenced to a minimum 18-year jail term for murdering hotel worker Janelle Patton, is challenging his conviction.
Ms Patton's badly batteredbody was found at a popular picnic spot on the tiny Australian territory on Easter Sunday, 2002.
At his trial, McNeill maintained his confession had been complete rubbish, the product of his mentally disturbed state.
In the Federal Court in Sydney today, Peter Garling, for McNeill, said the confession did not reflect the objective evidence about the crime, only publicly known information.
"We submitted to the jury, and we submit to this court, when one examines a confession such as this, one is left with very real doubt whether there was an admission which reflects what occurred," he said.
"The law has a long experience in recognising that people confess to crimes they do not commit."
Mr Garling today said McNeill told police he accidentally hit 29-year-old Ms Patton while driving his car, but the lawyer said medical evidence revealed she had not been in an accident.
McNeill also told police he had put her in the boot and stabbed her, but Mr Garling said a pathologist said four separate instruments had been used to attack Ms Patton.
He said McNeill only referred to a knife and his answers showed "no knowledge whatsoever" of the mix of weapons.
The answers had been vague in detail and did not reflect knowledge which the killer would have had.
Mr Garling also said McNeill had confessed to the crime after police significantly overstated the forensic evidence against him.
He said the thrust of the police statements was that they had "an overwhelming case" against him.
But he said the three forensic matters put to McNeill - including his fingerprints being on the plastic which covered Ms Patton's body - were overstatements.
Mr Garling said the trial judge should not have allowed the confession to go before the jury as it had been "induced" by an untrue representation.
The Crown is due to make its submissions tomorrow.
