He was 19 years old when he murdered Beale in a violent attack that left the father-of-two unconscious with unsurvivable brain injuries near the Tukituki rivermouth on Waitangi Day last year.
After a guilty verdict at the end of a four-day trial last November he appeared in the High Court at Napier yesterday where he was sentenced to life imprisonment with a minimum non-parole period of 14 years.
Puna attacked 45-year-old Beale just hours after meeting him in a chance encounter in the seaside settlement on the evening of February 5.
Beale loved to fish, often socialising with others at the beach, and met Puna this way before sharing his home-brew vodka with him throughout the night.
The pair had returned to Beale's home for more alcohol that evening when the 45-year-old accidentally tripped and pulled Puna down with him.
The court heard this was the catalyst for the fatal attack that followed in which the enraged Puna delivered 13 full-forced kicks to Beale's head during a period of 40 to 60 minutes before urinating on him and leaving him for dead.
Members of the public found Beale's bloodied and beaten body on Waitangi Day morning and he died the following day after life support was switched off.
In his sentencing submissions Crown prosecutor Steve Manning described the attack as "senseless and gratuitous violence" and said it showed a complete lack of humanity towards Beale.
He submitted the brutality and cruelty of Puna and the vulnerability of Beale warranted a minimum non-parole period of 17 years.
Defence lawyer Eric Forster argued for a sentence of life imprisonment with a minimum non-parole period of 12 years.
His client's disadvantage, youth and level of intoxication meant he had trouble regulating his behaviour as opposed to having a sinister state of mind, he said.
"This is a case where someone has lost control rather than a callousness to another human being's life."
Puna's smile may be perceived as callousness but it was actually a reflection of his youth, immaturity and struggle to deal with the gravity of what he had done, Forster said.
Justice Cull QC began sentencing by acknowledging Puna would receive a second strike under the three-strikes legislation for the offending after receiving his first for aggravated robbery in 2016.
This meant he was subject to a sentence of life imprisonment without parole unless it was manifestly unjust, and Justice Cull QC said after careful consideration she had determined it would be.
Puna had six previous convictions and a pre-sentence report stated he was at high risk of reoffending and an extremely high risk of causing harm to others, she said.
A cultural report also indicated a number of factors to consider including his mother's prenatal use of alcohol and drugs, low socioeconomic status and exposure to domestic violence.
She accepted Puna was remorseful with positive rehabilitative prospects but said he had used extreme violence against a vulnerable person and prevented him from getting help.
She imposed a minimum non-parole period of 14 years' imprisonment, stating it would hold him to account for the harm he had caused.
Puna had earlier pleaded guilty to stealing the Beale's cellphone and vaping device and yesterday he was sentenced to one month in jail for each of the two theft charges to be served concurrently with his sentence for murder.
Victim impact statements provided by Beale's mother and sister described how traumatic his death had been for the family and how disturbing they found the details that emerged during the trial, she said.
Puna and Beale's families sat quietly in the public gallery throughout the sentencing.
Detective Sergeant Craig Vining said Beale's entire family had shown a tremendous amount of courage throughout the last year, particularly when listening to confronting evidence raised during the trial.
"On behalf of the investigation team I'd also like to thank the members of the public who contacted us with information, witnesses involved in the trial and the Haumoana community for their assistance and resilience," he said.
