It was also submitted his crime met other criteria in section 104, such as Mrs McCullough's vulnerability as an unsuspecting pedestrian out for exercise on the country road where she was struck, and that Kinghorn acted with a high level of brutality, cruelty, depravity, or callousness.
But the judge rejected those arguments as well, saying vulnerability was meant under the Act to refer to factors like a victim's age, youth or degree of disability, while the levels of brutality needed to be much higher than those usually associated with a homicide.
He settled on 15 years as the minimum period of jail to be served, but discounted that by two years to recognise Kinghorn pleaded guilty, appeared to show genuine remorse which was registered immediately after the offence, had offered to undergo a process of restorative justice, and indicated he had some insight in the likely causes of his actions.