James Tuwhangai (19) was originally jailed for two years after admitting a prolonged attack on his ex-girlfriend, but after three months behind bars — just before Christmas — he was released.
The teenager is now serving a nine-month period of home detention instead, after Justice Rachel Dunningham granted an appeal in the High Court at Dunedin.
She noted Tuwhangai turned up to a meeting with Probation in Mongrel Mob colours with swastika tattoos on his hands and was concerned time in prison would see him recruited by the gang.
"In my view, Mr Tuwhangai is particularly vulnerable to embarking on a career of offending, and this would only be exacerbated by a minimum of a year in prison," the judge said.
"There is a clear fork in the road for Mr Tuwhangai. His family are reaching out to him and urging him to take one path, but I suspect the gangs and prison life will be urging him to take another."
JustSpeak projects co-ordinator Kirsten Van Newtown said the case was an acknowledgement of the inherent problems with imprisoning people.
"Prisons by their very nature are sites of violence, and are wholly inadequate places to be carrying out the complex work of rehabilitation for people who have offended. Sending people to prison in the hopes of addressing the root causes of their offending doesn’t work — and we can see this clearly in our shameful recidivism rates," she said.
Transforming Justice Foundation chief executive officer Scott Guthrie agreed.
He said rehabilitative courses in prison were oversubscribed and largely unsuccessful when it came to sparking meaningful change in inmates.
"The Government isn’t coming up with any better solutions because the Government doesn’t have the balls, and National was guilty of that, too," Mr Guthrie said.
He was sceptical of whether Tuwhangai would be helped on home detention.
The teen would go right back to the environment in which the offending happened, he said.
"This young fella is a clear example of how broken the system is, because we’re not helping him one tiny bit," Mr Guthrie said.
Tuwhangai committed the offences against his former partner in January last year.
During the incident, which lasted several hours, he punched the victim repeatedly, strangled her, broke her phone, damaged her car and scattered her clothes around a paddock.
In a pre-sentence interview with Probation, he twice referred to the woman as a "f... b..." and said she was "staunch for a white chick".
University of Otago law lecturer Danica McGovern said the lack of reference to the victim in the appeal judgement was striking.
"His father (and several children) were present at the time, indicating that his family is unlikely to be able to stop him from doing it again. He strangled the victim, which is a risk factor for lethal violence," she said.
How to deal with criminals was a "real conundrum" when those imprisoned could be more likely to offend in future, Dr McGovern said.
"We desperately need better ways to respond to offending that decrease the likelihood of reoffending, keep victims safe, and hold offenders accountable," she said.
