A “courteous and kind” gang member has come a long way since he helped a friend shoot and critically wound a group of rival gang members who were out celebrating a 21st birthday in Wellington, his lawyer says.

Mel Petersen was sentenced in the Wellington High Court this morning for his role in the shooting, which left three people wounded and one person needing to have his eye surgically removed.

His rehabilitation was not enough to spare him from prison though, with Justice Rebecca Ellis noting the sentence needed to reflect the “awful” effect on the victims.

Petersen and his co-offender Mana Lawson were out drinking in Wellington city in the early hours of April 23 last year. The pair were members of the Killer Beez gang, and were drinking with members of the Mongrel Mob when they encountered members of a rival gang, the King Cobras.

The rival group were out celebrating victim Dekiah Poe’s 21st birthday.

About 5am, Petersen’s group went to find the rival gang members, with Petersen, then 21, stashing a 12-gauge shotgun in his trouser leg.

They approached the group outside Calendar Girls and there was a brief scuffle in which one of Petersen’s group was punched in the face, and they retreated.

Mana Lawson was sentenced in September. Photo / NZ Police

Petersen and Lawson regrouped, and Petersen withdrew the concealed shotgun and handed it to Lawson, who fired it from his hip, hitting the three victims in the head.

Poe and a second victim, Imani Tuala, received serious head injuries and underwent various surgeries including brain surgery.

Tuala received gunshot wounds to his face, neck, chest, brain and tongue and still suffers weakness.

Poe had a ruptured eye with shotgun fragments lodged in his brain and heart.

Justice Ellis said he had to have his eye removed.

The third victim, Waitoharuru Karaitiana, was wounded on his left cheek but refused medical assistance.

Lawson was sentenced in September for his part in the offending, having previously pleaded guilty to charges of unlawfully possessing a firearm and a representative charge of wounding with intent to cause grievous bodily harm. He received a four-year prison sentence.

In court today, defence lawyer Peter Ross said when he first started acting for Petersen he could best be described as a “teenage boy”, though he was not actually a teenager. Over the course of acting for him, he saw him develop into a “respectful, courteous and kind young man,” he said.

Ross said this spoke volumes to Petersen’s capacity for rehabilitation.

Petersen’s partner of six months also told the court of the change she had seen in him over the past year, saying he had been helping her care for her terminally ill child.

“He’s been massive in caring for her,” she said.

Justice Ellis said Petersen had been engaging with the Grace Foundation, an organisation that works with marginalised members of society to help them lead healthy and sustainable lives.

She noted pre-sentence reports showed Petersen had a traumatic childhood and was placed into state care at the age of 13, where he was physically abused. He also began drinking and taking drugs around that time, and still suffered from an MDMA addiction.

She said the Crown accepted his background and addictions had a causative effect on his offending.

“You have said, and I believe you, that you want to leave the gang and get a job,” she said.

Justice Ellis said there were “a lot of positives” for Petersen, but the sentence she gave still needed to reflect the seriousness of the offending.

She sentenced him to three years and six months in prison. The sentence included discounts for his guilty plea to unlawful possession of a firearm and wounding with intent to cause grievous bodily harm. He also had discounts for youth, background, and steps towards rehabilitation.