Ewen Macdonald's disturbed personality profile may mean any release plan, regardless of its conditions, would be insufficient to address his assessed risk of reoffending, the parole board found in declining his parole application.
Macdonald has been in custody since April 2011, when he was arrested for the murder of his brother-in-law, Feilding farmer Scott Guy, in July 2010.
He was acquitted on that charge last year but jailed for five years for a string of other offences, including arson, vandalism and killing calves.
Macdonald had "a significant personality disturbance" and in situations involving revenge, entitlement, perceived injustice, and envy, would continue to pose a clinically significant risk of reoffending.
With two years and four months remaining of his sentence, Macdonald was denied parole as the board could not be satisfied he would not pose an undue risk to the community if released.
The board relied on a psychiatrist's report which described him as displaying narcissistic and other personality traits.
Macdonald said poaching "relieved the stress" he was under, and it was a way of "putting things back in neutral in his favour" as "the scales were out of balance".
He made similar comments about burning down Kylee and Scott Guy's homestead and damaging the house - that it was a "challenge" to get away with doing something wrong, that he was "jealous" and that he was seeking revenge.
Macdonald said he was "sickened" when he thought about his actions, and that he had changed - but the parole board did not accept this.
He waited 18 months before pleading to the charges, and only confessed in the face of incontrovertible evidence, the parole board said.
Despite Macdonald's record in prison over the past year, where he has maintained his minimum security classification, the parole board was concerned he had not been tested in stressful situations which could trigger reoffending.
In his application for parole, Macdonald submitted he could be subject to additional special conditions including an overnight curfew, GPS monitoring, and a prohibition on entering the North Island.
"But, given his personality profile, we wonder whether any plan, with any number of conditions, or any additional therapy, is sufficient to address his assessed risk," the parole board's decision says.
Macdonald had proposed reintegration into the Christchurch community, away from Feilding where his crimes were committed.
Macdonald's sentence ends on April 6, 2016.