The Crown has lost the first appeal challenging the three-strikes law.
Murderers Shane Harrison and Justin Turner could have been jailed for life without parole under the three-strikes law, but the sentencing judges ruled it would be manifestly unjust to do so.
Shane Pierre Harrison, 46, is appealing his conviction for murdering Alonsio Matalasi, 25, at Petone in August 2013. His previous convictions were for indecent assault and manslaughter.
Justin Vance Turner, 30, pleaded guilty to murdering homeless man Maqbool Hussain in a brutal hour-long attack in Auckland in March, 2014. He'd had a first-strike warning for wounding a woman in 2011.
Crown lawyer Matthew Downs has outlined the safeguards in the three-strikes law, including age, the seriousness of the crimes that qualify for a strike warning and the manifestly unjust clause.
But in the Court of Appeal today, the Crown's appeal against Harrison's sentence was dismissed, and its appeal against Turner's sentence was only partially granted in that his minimum life sentence was increased from 15 to 17 years.
The three-strikes law came into effect on June 1, 2010. It requires a person convicted of murder after committing a "serious violent offence" to be sentenced to life imprisonment without parole, unless that would be "manifestly unjust".
The crux of the appeals against Harrison and Turner's sentences regarded the meaning of "manifestly unjust".
The Court of Appeal concluded the "low culpability" of Harrison's offence, along with his attempts to rehabilitate, age, and the views of the victim's family, would have made a life sentence "grossly disproportionate".
Meanwhile, the Court concluded, although the circumstances of Turner's offending were brutal, his age, guilty plea and mental health difficulties made a whole life sentence grossly disproportionate.