Over several weeks, jurors acquitted a few of the accused and found others not guilty on some charges. The eight at the final trial changed their pleas to guilty on the second day and the prosecution dropped other counts.
Today 16 gangsters - all with criminal records - were jailed for terms ranging from seven-and-a-half to three years.
Two who had given evidence against fellow Mongrel Mob members at trial now genuinely feared for the safety of their families and themselves, Justice Alan MacKenzie was told.
It was virtually unheard of for a gang member to side with the Crown in a High Court trial, said lawyer John Mathieson.
His client believed "his life will be taken because of this grave breaking of Mongrel Mob rules."
Crown prosecutor Russell Collins acknowledged that a number of other gang members involved in the gunfight would not have gone to trial without the co-operation of the pair who ratted on them.
During the lengthy sentencing process, Justice MacKenzie stressed repeatedly that the events of the chapter's internal conflict deserved "the highest level of denunciation."
It was not acceptable in a civilised society for people to resort to a gunfight to settle their differences, he said.
The fact that some members were not convicted on some charges did not lessen their seriousness.
Trouble started on August 9, 2010, when a few Wairoa Mob members expressed dissatisfaction with long-term president Rangi Tamati, now aged 50. They relieved him of office by beating him and taking his patch.
There was to be a meeting at the gang pad at noon next day to discuss the leadership issue.
Humiliated, Tamati went off to Napier to get reinforcements, including his son and brother. At least six vehicles in convoy returned early the next morning, some carrying firearms.
Meanwhile, expecting retaliation, other senior Wairoa Mobsters Vincent Monika, Saul Waihape and the late Kelly Gemmell, along with a handful of their supporters, holed themselves up in the pad building. They also had guns.
Gemmell, 39, suffered severe shotgun wounds to the face during the brawl which ensued. He died later in hospital from what a pathologist determined was an unrelated aneurism.
Outside the pad, Claude Edwards, 42, received two shots to the leg and left the scene. He did not seek medical help until the next day, when he was hospitalised to have a bullet removed.
From inside the pad, Monika alerted police. Two Wairoa detectives arrived and cordoned off the area. They called in out-of-town reinforcements, including the Gisborne Armed Offenders Squad.
Justice MacKenzie said the warring sides must bear equal responsibility for the gunfight. Both had planned retaliation and either group could have avoided the outcome.
He accepted, however, that there was no evidence 10 of the accused had taken an active part in the violence "beyond your presence as part of the group".
In recognition of that, they were sentenced to three years behind bars for participating in an organised criminal group.
Those involved, what they were charged with and their sentences:
* Vincent Monika, 46, Wairoa: Participating in an organised criminal group, 3 years 9 months jail; three firearms charges, 1 year for each, to be served concurrently. An unrelated charge of supplying methamphetamine, 2 years.
* Saul Waihape, 47, Wairoa: Participating in an organised criminal group, 4 years imprisonment; three firearms charges, 1 year each, to be served concurrently.
* Rangi Tamati, 50, Wairoa: Participating in an organised criminal group, 6 years 3 months; attempting to pervert the course of justice, 1 year 3 months cumulative.
Participating in an organised criminal group:
* Alexander Tamati, 54, Napier: 5 years 6 months.
* Claude Edwards, 43, Napier: 5 years six months.
* Ronald Rigby, 49, Wairoa: 4 years 3 months.
* Harry Minhinnick, 23, Napier: 3 years 6 months.
* Sovite Sua, 39, Napier; Terry Stone, 27, Wairoa; Laddie Tamati, 24, Napier; Glenn Te Kahu, 34, Napier; Bradley Ngaronoa, 32, Napier; Jeremy Mita, 22, Napier; Paul Johnson, 45, Wairoa; Peter Lavu Lavu, 26, Wairoa; Frederick Blanford, 35, Wairoa: All three years imprisonment.
