The man behind the "merciless shooting of two police officers" that left one dead has failed to trim his jail sentence that will see him behind bars for at least 27 years.

Today the Court of Appeal dismissed Eli Bob Sauni Epiha's bid to have his sentence reduced, with it finding the outcome was not manifestly excessive - despite the offender's young age - and that he is a violent man from whom the community needed protection.

Epiha, now 26, was convicted of murder after gunning down two unarmed police officers after fleeing a traffic stop and crashing his car in West Auckland in 2020.

On the day of the June 19 shootings, constables Matthew Hunt and David Goldfinch were parked up and conducting routine traffic checks in Massey.

Epiha, who had two guns in his car, was driving towards Ranui when he crashed and injured a member of the public.

He then took a semi-automatic rifle from his vehicle and fired 14 shots at the two constables, killing Hunt and injuring Goldfinch, who had been approaching to help the injured bystander.

Epiha admitted killing Hunt but denied it was intentional. He was, however, sentenced on the basis the murder was deliberate. He pleaded guilty to dangerous driving causing injury and was later found guilty at trial for attempting to murder Goldfinch.

He was sentenced to life imprisonment with a minimum period of imprisonment (MPI) of 27 years, making it one of the longest jail terms handed down in New Zealand.

• Eli Epiha tells jury he ignored dying officer's plea for help
• Eli Epiha thought about helping Constable Matthew Hunt
• Wounded constable kept away from ED as doctors tried in vain to save partner's life
• 'Chilling' murder of Constable Matthew Hunt: Killer appeals 'crushing' sentence

Constable Matthew Hunt was killed while on active duty on June 19, 2020. Photo / Supplied

At the appeal hearing held earlier this month, Epiha's lawyer, Mark Edgar, described it as "a crushing sentence imposed on what is still a young man".

He argued it was manifestly excessive and had failed to uphold the sentencing principle of rehabilitation.

Edgar submitted the MPI starting point of 29 and a half years' imprisonment, adopted by the High Court at sentencing, was too high and that insufficient credit was given for Epiha's personal mitigating circumstances.

But the Crown pushed back, saying the outcome was appropriate as it involved killing and attempting to kill two police officers.

Prosecutor Brian Dickey said the "cold, unprovoked" killing caused "the highest level of concern to the public".

The way Epiha shot Hunt and Goldfinch showed it was a "determined effort to kill police officers", Dickey said at the appeal.

"Mr Epiha had no motive to kill these police constables. He was just killing them..."

In the Court of Appeal's decision, released today, it found the starting point taken by the High Court was appropriate, as was the credit given for mitigating circumstances.

"Mr Epiha used a high-powered weapon and fired a large number of bullets, the shooting endangered nearby members of the public," it said.

"[He] was given a chance to leave by the police but chose not to, and the victims were police officers performing their duty."

Epiha will not become eligible for parole until he is 52 and while the Court of Appeal acknowledged it was a "very long sentence for a young man", it found it was not manifestly excessive.

"It is, however, a proportionate response to what was the merciless shooting of two police officers, the taking of a young constable's life and an ongoing reluctance by Mr Epiha to take full responsibility for his actions.

"He is a violent man from whom the community must be protected."

- Tara Shaskey, Open Justice