A hearing to settle a dispute over facts relating to the killing of a prison officer at Springhill Prison in north Waikato has been held in the High Court in Hamilton.
Latu Kepu, 22, pleaded guilty to the manslaughter of prison officer Jason Palmer in May this year.
Mr Palmer died from head injuries after he was punched and fell to the ground while opening a cell to let Kepu out.
Justice Heath told the court that before sentencing on Friday, the Crown needs to prove beyond reasonable doubt that the attack on Mr Palmer was premeditated.
He told the hearing on Thursday the defence will need to prove its submission that Kepu was genuinely remorseful.
Officers gave evidence that Kepu had been put on report by Mr Palmer in the days leading up to the attack and that Kepu had spoken of "getting him".
The defence says Kepu was provoked because Mr Palmer had verbally abused him in the days leading up to and on the morning of the attack.