Then on September 25, 2015, while in Manawatu Prison, Te Poono attacked a fellow prisoner.
They were both in the exercise yard when Te Poono stabbed the victim repeatedly with a sharpened pencil.
Reading from the summary of facts, Justice David Collins said the attack happened "without warning or provocation".
"The victim did not know you.
"As the victim backed away, raising his arms to protect himself, you continued to advance upon the victim, stabbing him with the pencil.
"The victim suffered a fractured cheekbone and multiple cuts to the front, side, and rear of his head."
Three days later, it was three prison officers who were attacked.
The officers were manning a food trolley, and unlocked Te Poono's cell so that he could put his meal tray on the trolley.
However, he had sharpened a piece of perspex, and was holding the shank beneath the tray.
"You pushed past Officer Spooner and lunged at Officer Kumar, who had been pushing the meal trolley," Justice Collins said.
"You stabbed Mr Kumar in the head, causing him to fall to the ground.
"You then stabbed him again in his right shoulder."
Kumar suffered a gash to the head, and two stab wounds to his shoulder.
Spooner tried to stop Te Poono, but was stabbed in the head, and fell to the ground. His injuries required stitches.
When a third officer tried to restrain Te Poono, he was stabbed in the face and chest. He wounds required surgical glue.
Te Poono was moved to Rimutaka Prison, where more violent incidents occurred.
On October 19, 2015, he attacked another prisoner in the exercise yard, striking him 23 teams in the head and body.
As the man was trying to get off the ground, Te Poono then kicked him in the head.
On November 12 he once again attacked three Corrections officers, using a concealed sharpened pencil.
They were taking him back to his cell from the exercise yard when he attacked them.
"Without warning, you struck the Corrections officer on your left side with the pencil, puncturing his right cheek," Justice Collins said.
"You then immediately punched the right side of his head, knocking him to the ground.
"You attempted to strike the other two Corrections officers when they intervened to stop the attack."
Te Poono has 90 previous convictions, including 11 prior convictions for violent offending.
Justice Collins noted two health professionals had independently diagnosed Te Poono as suffering from a methamphetamine-induced psychosis at the time of his most violent offending.
He received treatment in January 2016 for paranoia and auditory hallucinations.
Justice Collins also noted Te Poono had a turbulent personal history.
He left school early and was introduced to alcohol, drug use, and criminal activity.
At the age of 14, he was placed into the care of a person living at the Mongrel Mob headquarters in Turangi.
Te Poono has since had a long association with the gang.
Justice Collins considered preventive detention for Te Poono, which is the strongest sentence a judge can give in New Zealand.
It is a prison sentence with no fixed end point.
Prisoners could eventually be released on parole, but could still be recalled to prison at any time for the rest of their life.
However, Justice Collins decided against it, saying the psychosis from methamphetamine use was a key factor.
"Both health assessors have recognised mental health issues contributed to the seriousness of your current offending.
"They note that your risk to the community will be lessened if your mental health issues are controlled."
Te Poono was sentenced to eight years and six months jail, with a minimum imprisonment of four years and nine months.
In November 2016, Te Poono was found not guilty by a jury of murdering Samuel Culling, also known as Samuel Badawi.
Culling was shot in the back of the head with his own sawn-off 12-gauge shotgun, on August 5, 2015.
