Kiyahn Tapiki, 20, was jailed for two years and two months when he appeared in the Dunedin District Court yesterday over two incidents of serious domestic violence.
Judge David Robinson noted the defendant was serving a sentence of intensive supervision and community work at the time of the attacks.
"It’s really hard to understand why these offences have occurred with the background of you being fully engaged in the sentence and having the benefit of a number of supports," he said.
Counsel John Westgate sought further information from his client before sentencing yesterday but could provide no clarity.
The only scant insight into Tapiki’s mindset came from comments he made to police when he was arrested in May.
"He stated he was angry and just wanted to hurt them."
Tapiki was living with the victims at their St Kilda home when the first incident occurred in December 2023.
He confronted his partner over a message on her cellphone then smashed the device against the wall.
After throwing the woman to the ground, Tapiki stomped on her back with his bare feet at least 10 times.
When she tried to get up, he slammed her down again, punching her repeatedly in the back of the head, ripping off her pyjama shorts and stomping her five more times.
The victim tried to escape but Tapiki grabbed her and forced her back into the room, threw her into a window and punched her in the nose
Six months later, the woman awoke to the defendant raging about his phone being broken.
Tapiki went berserk, flinging items around the bedroom, flipping over drawers and ripping down curtains, the court heard.
The noise alerted the woman’s mother, whose intervention did nothing to calm the defendant.
She left the room and when she returned, she saw Tapiki punching her daughter.
A police summary described how the woman desperately shielded her daughter, sustaining numerous punches and knees to her head and body.
She told the court yesterday she had taken a month off work and was "devastated" by the ordeal.
"I could see it in his eyes, he really wanted to hurt my daughter.
"I really can’t sleep or shut my eyes because the images are so clear of the assault."
The incident had "driven a wedge" between the mother and daughter, Judge Robinson said.
Being together was triggering, both had endured flashbacks and were undergoing counselling.
Mr Westgate said Tapiki had been behind bars for the last eight months and had used his time undertaking any rehabilitation programmes available.
The defendant apologised to his ex-girlfriend at a restorative justice meeting and accepted their relationship was now over.
The judge granted a protection order in favour of the victim and ordered Tapiki pay $1540 reparation.
He declined an Otago Daily Times application to photograph the defendant.