New Zealand / Crime

Sex offender handed five-year supervision order by High Court

06:47 am on 15 December 2025
Catherine Hutton, Open Justice reporter

First published on

Nathaniel James Mahoney at his recent hearing in the High Court at Wellington to decide if he should be the subject of an extended supervision order. Photo: Mark Mitchell

WARNING: This story details sexual offending

A man with a history of sexually attacking women - including one whom he raped after meeting at a pop culture event, while he was dressed as The Joker - will remain under supervision.

Nathaniel James Mahoney was jailed for 10 years in 2015, after being convicted on sex and physical violence charges against four women.

At a hearing last month in the High Court at Wellington, the Department of Corrections sought a 10-year Extended Supervision Order (ESO) for Mahoney.

Corrections lawyer Anselm Williams submitted that Mahoney's past conduct showed a "pervasive pattern" of behaviour.

An ESO allowed Corrections to monitor and manage the long-term risk posed by high-risk offenders, and to protect the public.

Mahoney's lawyer, Charlotte Brook, said her client didn't oppose the order or the conditions, but argued it should only be imposed for up to five years.

Justice Paul Radich's recently released decision referred to Mahoney's original sentencing notes, including an observation by the sentencing judge that Mahoney had "attacked" a young woman - "there is no other word for it".

After meeting her at the Armageddon Expo, while he was dressed as the Joker, the two went back to her house. Once there, he raped her twice.

Mahoney choked the woman, and also bit her neck, shoulders, ribs and stomach, in some cases breaking the skin, as well as leaving scratches, bruising and abrasions over her body.

At sentencing, the judge referred to the woman, who had a condition, as particularly vulnerable.

"In my judgement, Mr Mahoney, it would have been reasonably clear to you that she had a degree of vulnerability to say the least."

The decision also referred to a second sexual assault.

That incident occurred at a residential lodge in 2012, after Mahoney followed a drunk and vomiting woman he knew back to her room, and got into bed with her.

Ignoring her pleas for him to leave and attempts to push him away, Mahoney touched her body and private parts.

The following year, a third assault, involving a woman who was also known to Mahoney, began after he grabbed her by the hair.

As she tried to get away, he grabbed her breast and pulled her towards him, causing considerable pain.

High risk of future sexual offending

Corrections first applied for an ESO in 2024, before Mahoney's release from prison.

Following his release in February, an interim supervision order was granted, requiring him to live at Te Korowai, a supported living facility on the grounds of Rimutaka Prison, offering 24/7 oversight and support.

Last month's hearing sought an ESO for the maximum 10-year period.

Two of the three experts, who prepared reports for the hearing, assessed Mahoney's risk of re-offending as high or very high, noting that any re-offending would likely involve a vulnerable woman he knew.

One of the reports also noted that Mahoney had a "complex risk profile", including mental health and personality factors, and neurodivergence.

He is currently on medication for ADHD and bipolar disorder.

Justice Radich's decision noted the three incidents showed a clear pattern of Mahoney forcing himself on young, sometimes vulnerable women, irrespective of their objections.

"The key factor on which the experts appear to agree is that the main contributor to Mr Mahoney's future risk of offending is his lack of understanding of consent, especially in the context of his sexual preference for BDSM. He prefers to be 'dominant' during intimacy."

The judge noted there was a "pervasive pattern" of serious sexual offending, as well as a high risk of future sexual offending, thereby meeting the requirements for an ESO.

Mahoney, who was in his 20s at the time of the offending, was now 36 and continued to maintain the sex was consensual.

However, towards the end of his sentence, he began treatment and had now undertaken a considerable number of sessions.

"Concerns remain about Mr Mahoney's ongoing denial of responsibility for the serious sexual offending he has committed," the decision stated. "It is intended that his treatment will be long term."

The decision went on to state that, without significant treatment, Mahoney's pattern of serious sexual offending was sufficiently pervasive to serve as a predictor of his future conduct.

Accordingly, Justice Radich imposed a five-year term for an ESO, with the Parole Board to review the conditions of Mahoney's order in the new year.

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Sexual Violence