The man who mowed down a runner and admitted to murdering her should spend more time in jail for the brutal nature of his crime, the Crown believes.
Matthew Kinghorn, who admitted to murdering 45-year-old Anne Elizabeth McCullough while she was out running on a semi-rural road in New Plymouth in October 2012, is serving a minimum non-parole period sentence of 13 years for the crime.
The sentence, handed down by Justice Rodney Hansen in the High Court at New Plymouth last year, was incorrect, the Crown has submitted.
Today, Crown lawyer Madeleine Laracy argued in the Court of Appeal in Wellington that Justice Hansen committed "errors of law" in deciding on the sentence in December.
At the time, Justice Hansen settled on 15 years as the minimum period of jail, and then discounted that by two years for several mitigating factors - including Kinghorn's guilty plea and appearance of showing genuine remorse.
The Crown had argued for Kinghorn to serve the maximum non-parole life sentence of 17 to 25 years, and presented evidence alleging he murdered Mrs McCullough in the course of sexually offending her.
According to sentencing legislation, this would amount to a maximum non-parole life sentence of at least 17 years for Kinghorn.
However, Justice Hansen found against this, saying there was insufficient evidence to show Mrs McCullough had been killed in the course of sexual offending.
Today, Ms Laracy submitted Justice Hansen had made several sentencing remarks actually agreeing with the Crown's submission that Kinghorn's attack on Mrs McCullough had been sexually motivated, and her death was therefore a "reckless killing" resulting from the attack.
The Crown's case is that Kinghorn had "a motivation to disable her [Mrs McCullough], to take her away, to engage with her in a sexual away she didn't consent", Ms Laracy said.
In addition to this, Ms Laracy submitted the nature of Kinghorn's offending had been carried out with extreme callousness and depravity - consistent with those required for a minimum period of imprisonment of 17 years or more.
Kinghorn's lawyer, Julian Hannam, disagreed with this and stood by Justice Hansen's original sentencing decision.
He also provided evidence showing Kinghorn's attack on Ms McCullough had not been sexually motivated, proving the sentence assigned last year had been correct.
It was also the Crown's job to prove any aggravating factors - such as sexual offending - beyond reasonable doubt, which it had not done, Mr Hannam added.
Justices Mark O'Regan, Grant Hammond and Lynton Stevens reserved their decision.