"I have no doubt that if I impose a finite sentence, you will simply wait it out as you have done before and nothing would change," Justice Peters said.
Tawhai and his partner were together for about a year when he, driving them in her car, suggested they go for a walk to discuss their cooling relationship. The woman said she just wanted to go home.
Angered, Tawhai – still driving - punched her in the arms and shoulder and verbally abused her. When she tried to get out of the car, he grabbed her clothing around her neck.
He parked and dragged her out of the car and when she managed to get back in, punched her repeatedly in the face six or seven times, knocking one of her teeth out.
He pulled her from the car again – this time by her hair. Eventually, he stopped and drove her to his house where she changed out of her torn and bloodied clothes and realised she had lost control of her bladder.
Tearful and shaking as she read her victim impact statement in court, the woman said she still needed dental work as the force Tawhai used pushed some of her teeth up into her gums.
She was terrified during the attack. Tawhai fractured her eye socket and one of her fingers. She suffered bruising to her head and torso and had a black eye.
She still has headaches, migraines, cannot remember things, and aches constantly.
For the first time in her life, she was unable to work. She missed her employment and was suffering financially.
She sold her car because it gave her flashbacks.
She is constantly on edge and every time she hears a noise fears it is Tawhai.
Having since looked up media reports, she was now aware of his previous similar offences.
If he could do this to her – a "strong woman" - he could certainly, do it to another. He could even kill that next person, she said.
Justice Peters said, "sadly, not one thing the woman said was a surprise".
The crucial issue at sentencing was whether there was a need for preventive detention.
Justice Peters said relevant sentencing principles included deterrence and denunciation but also the need to protect the community from Tawhai.
Based on counsel's submissions, case law, and after discounts totalling 35%, the judge calculated a finite end sentence of three years, saying she could have imposed it with a two-thirds non-parole period.
But in her view, even if coupled with extended supervision, a finite sentence would not stop Tawhai from reoffending.
She agreed with Crown prosecutor Richard Annandale's submissions that Tawhai's past criminal history showed a pattern of him pledging remorse and insisting he wanted to change but taking little action, waiting out sentences and release conditions, then reoffending.
Tawhai's criminal history, which ran to 10 pages and included over 70 convictions, showed he had spent most of his adult life in custody and when not behind bars, had a proclivity for violence – especially against intimate partners, the judge said.
Tawhai's engagement with rehabilitative programmes over the years was limited. Between 2008 and 2018 he served the whole of a 10-year sentence for rape and in that entire time only did one, three-month course, which was for drug and alcohol abuse.
Counsel Arthur Fairlie argued against the need for preventive detention saying Tawhai was motivated to attend programmes. Fairlie pointed to aspects of expert health and other reports that stated Tawhai would respond best to programmes carefully tailored for his needs and delivered one-on-one.
His propensity to reoffend would also decrease as he got older.
Justice Peters accepted Tawhai had a tragic childhood, which directly contributed to his offending. He was intelligent and could make progress when he applied himself. She was willing to accept he wanted to change and that he should be given the means to do so. But preventive detention did not preclude that - in fact, it was more likely to incentivise it.