LAWYERS for the man found guilty of the brutal murder of Carly McBride say the jury should have been allowed to consider an alternative verdict of manslaughter and argued the judge failed to give an important direction to jurors as part of a push to have his conviction overturned and a new trial ordered.
The state's highest court - the Court of Criminal Appeal - sat in Newcastle on Thursday for only the second time since 2005 to hear one of the Hunter's most significant cases in recent memory.
The jury was left with no doubt he was the person who intercepted the 31-year-old after she left a house at Muswellbrook on September 30, 2014, and inflicted a number of blows to her head and back before dumping her body near the side of a lonely stretch of road outside Scone.
Ms McBride's skeletal remains were not found until August, 2016.
Newson, who had been in a brief relationship with Ms McBride at the time of her murder, was later jailed for a maximum of 27 years, with a non-parole period of 19 years and nine months, making him eligible for parole in August 2038.
Newson's lawyers, led by Sydney barrister Winston Terracini, KC, and Newcastle solicitor Mark Ramsland, launched an appeal against Newson's conviction, arguing he should be acquitted or a new trial ordered due to what they say were errors made by the trial judge, Justice Mark Ierace, SC.
Those "errors", which now form grounds of appeal, include not allowing the defence to explore an alleged "financial motive" of a key witness, not leaving the alternative charge of manslaughter by unlawful or dangerous act to the jury and a failure to give the jury a direction about drawing inferences in what was an entirely circumstantial case.
In responding to the appeal points on Thursday, Crown prosecutor Georgina Wright, SC, conceded a check of the transcript from the trial, sound recording logs and notes revealed Justice Ierace had omitted to give the jury a dedicated inferences direction in what was a purely circumstantial case against Newson.
But Ms Wright said the issue was how important was that omission given Justice Ierace made repeated references to the critical parts of the direction at other times during his summing up.
In relation to the jury being left the alternative count of manslaughter, Ms Wright said the injuries suffered by Ms McBride "totally negated that as being a rational view".
"On no rational view could a jury find that this was an attack where there wasn't an intention to cause really serious injury," Ms Wright said.
But Mr Terracini pointed to a defence medical expert who said Ms McBride's skull fractures could have been caused by a single blow if her head had hit the ground.
"The only issue that needs to be determined is the cause of the injuries," Mr Terracini said. "Do they exclude the application of unlawful and dangerous act? "If manslaughter had been left to the jury that would have been something [the defence] could have addressed on and not just on an intention to kill or cause grievous bodily harm. That it was a dangerous or unlawful act."
Another ground related to the defence not being allowed to cross-examine a key witness - who on their case was the last person to see Ms McBride alive - about what they claim was "dishonest" dealings with Centrelink.
Newson's lawyers submitted that evidence, if allowed, could have provided a "financial motive" for the witness to be upset with Ms McBride.
But Ms Wright said the ground had no merit, there was no basis the evidence would have impacted the witnesses's credibility and questioned how it would have proved he had a motive to kill Ms McBride anyway.
The final ground of appeal was a broad one; that the verdict is unreasonable and cannot be supported by the evidence.
And Ms Wright spent some time taking the three-judge panel through the strands of circumstantial evidence that, at the conclusion of his trial, had left the jury with no doubt that Newson was responsible for murdering Ms McBride.
The three-judge panel reserved its judgment.