'I was really depressed about everything that happened to me, and it made me make some really poor decisions,'Filimoemaka told the court.

A Linton soldier who pleaded guilty to bottling another soldier and meting out "barracks justice" has been sent to military prison for three months, but was "let down" by the army, a judge has ruled.

Private Sosaia Tassy Albert Junior Filimoemaka, 24, pleaded guilty at a Court Martial of New Zealand at Linton Military Camp on Monday before Judge Duncan Harvey and a panel of three senior military members.

He faced three charges, doing an act to the prejudice of service discipline, failing to comply with written orders and assault with a weapon, related to two incidents at the camp in Palmerston North in November 2014.

Murray WIlson/Fairfax NZ Private Sosaia Tassy Albert Junior Filimoemaka pleaded guilty to three charges at Court Martial.

The charges related to two incidents, one where he hit another private over the head with a bottle and another where he forced two others to drink until one of them was sick at Linton Military Camp.

The panel returned its verdict at 2pm, after adjourning for lunch, and beginning deliberations at 1pm.

"This type of behaviour within the New Zealand Defence Force is completely and utterly unacceptable," the judge said.

The judge said Filimoemaka was a senior private and had the role of a supervisor to newer privates, and the case was a "clear abuse of power".

Filimoemaka's leg injury, and the death of two close friends, as well as a serious attack on him in a bar in Palmerston North, where he was stabbed four times with a knife and a broken bottle, had contributed to his behaviour declining.

The court noted the efforts Filimoemaka had made since, and acknowledged that the army had failed him.

"The system severely did let you down after that leg injury. The court is concerned about that and accepts that would have something to do with your mindset at the time of the incident."

The judge said the court had "struggled" with his sentencing.

"You were let down and you were let down badly, and that undoubtedly contributed to your turning to alcohol."

The judge told Filimoemaka that he had let himself down, this regiment down, and the army down, but they did not consider him "a lost cause".

"You are very, very lucky, it is only the combination of circumstances that has saved you."

HIS ACTIONS

On November 22, 2014, Filimoemaka, was among a group of four men who approached another private, not known to him, who was sweeping up rubbish outside his barracks about 1am.

They confronted the man and questioned him on being a "pogue", a non-infantry member, and when he responded "what's wrong with that", Filimoemaka, unprovoked, smashed a bottle over his head.

He was helped back to his room by one of the men, but suffered swelling and bruising and was treated at hospital before discharging himself.

Filimoemaka later told police that when he was drunk he developed a dislike for non-infantry members, and that he had "never hit anyone over the head with a bottle before", and wanted to see if it would "smash over his head, like he'd seen in the movies".

In the second incident, Filimoemaka decided to mete out some "barracks justice" to punish some new soldiers who had failed to show up to a follow-up meeting after being ordered to clean up their barracks. Instead they went to a junior ranks bar at the camp.

He ordered them back about 4.30pm to "deal with them", and gave them the choice of being "knocked out", "thrashed" or drink with him.

When they chose the latter, he made them purchase alcohol, and when they arrived back with a pack of 24 cans of Tui and a cask of wine, a breach of the amount allowed in barracks, he insisted they drink it all.

One man became sick, but was not allowed to leave until after midnight, after the other promised to drink his share. The incident didn't end until the remaining man managed to call a friend about 3.15am, and asked them to call military police.

Filimoemaka wept while reading out an affidavit describing how he'd had a tough upbringing in South Auckland, and grew up in a poor Tongan family without a father.

Prosecutor Tom Gilbert had sought dismissal, and said Filimoemaka had "trampled on the ethos and values underpinning the army", not once but twice, and it was not "tolerable or realistic" to retain him.

Dismissal was the second most serious penalty that could be imposed, the first being imprisonment in a civilian prison.

REMORSE OF A SOLDIER

Filimoemaka wept as he read out his affidavit for the court, describing how he would get into a lot of fights as a child and earned the respect of his neighbourhood for "sticking up for his family", he said.

"Being the oldest, I had to stay hard, and not let my emotions get the better of me."

He believed the army had saved him from ending up in prison, and he loved it, he said.

He called 2014 "the worst year of my life", with injury preventing him from working to the fullest extent in the job he loved.

In 2013, he broke his leg in multiple places during a rugby game, which saw him on sick leave for two months and then have trouble getting support around his specialist appointments.

He felt unsupported by the army at that time, and turned to drinking heavily "to make myself happy because my love for the army was fading", he said.

He had further complications with his leg when the pins were removed in early 2014, and that year he also had two childhood friends die, but he was unable to get leave to attend their funerals.

He was drinking daily, and on one trip to Shooters Bar in Palmertson North, he said he got into fight with a group of gang members, which resulted in him being stabbed multiple times.

He insisted upon being taken back to the barracks, not the hospital, where a friend stitched up his wounds.

In November 2014, when the incidents happened, he was on pain medication, still on light duties, felt unsupported and left out.

"Everything was getting to my head", he said.

"I was really depressed about everything that happened to me, and it made me make some really poor decisions."

By Christmas, he was 140kg, but with counselling, rehabilitation, a drug and alcohol course and boxing training, had since lost 34kg.

Filimoemaka cried as he described how sorry he was for his actions toward the three privates, and said he had a new direction and was on a new path now.

Among those called in Filomoemaka's defence was Major Gareth Seeds.

Seeds said when he first met Filimoemaka he was "sullen and withdrawn" but had he had since seen a 180 degree turn around in his behaviour.

He was working on light duties in the regimental police office.

He said Filimoemaka was "highly influenced" by those around him, and some bad influences in his life had since been removed.

He would be happy to retain him in the army based on his current behaviour and depending on his health issues, Seeds said.

Gilbert said there were aggravating factors in the attack - that it was "utterly unprovoked", that a weapon was used, and that the victim was hit on the head.

The offence in which Filimoemaka forced two privates to drink alcohol was contrary to standing orders and involved strong use of "barracks justice", which he did not have the authority to impose, Gilbert said.

There was an undercurrent of "violent bullying" in both incidents, and a general deterrent for the wider community that such behaviour would not be tolerated was required.

Filimoemaka had quickly accepted responsibility for his actions, was genuinely remorseful, assisted the private he assaulted to his room, and had publicly apologised.

He had offered to meet with each soldier involved in person to apologise and offered reparation.

His peers and senior officers had attested to his character, and this was uncharacteristic, and in the midst of difficult personal circumstances, defence lawyer Paul Murray said.

He had since stopped drinking, undertaken drug and alcohol and psychological counselling, and had found other gainful ways of occupying himself through boxing.

He had much to offer the unit and the community, Murray said.