A man with a lengthy history of stalking and attacking women has been jailed for life with a minimum non-parole period of 17 years for murdering his ex-partner Chantal McDonald in front of her children at their Christchurch home. 

But violent serial offender Nathan Boulter refused to stand in court in front of his victim’s family - including her teenage daughter who spoke for the first time about witnessing the murder - appearing by audio-visual link from another room in the court precinct instead. 

The Herald has been reporting on Boulter’s horrifying offending since 2011 - after his high-profile stalking, kidnapping and assault of his ex-girlfriend on Great Barrier Island. 

Since then, he has been jailed repeatedly for violent offending against women. 

Boulter, 36, stabbed McDonald, 37, to death in her Parklands driveway in July last year as she arrived home from the supermarket with her teenage daughter and seven-year-old son. 

He had been released from prison just 13 days earlier. 

Nathan Boulter appeared via AVL for sentencing at the Christchurch High Court. Photo / Chris Skelton / Photo 

After travelling to McDonald’s street on July 23, Boulter lay in wait - armed with a 19cm pig-sticking knife he had purchased a day earlier. 

He carried out a “frenzied” attack as McDonald went to lock her gates after pulling into her Lamorna Rd property. 

The 37-year-old was terrified of Boulter - who had sent her hundreds of messages and threats in the weeks leading up to the murder - and had taken to padlocking her gates to keep her family safe. 

Boulter was on prison release conditions at the time. 

Following the fatal attack, Corrections commissioned a review into Boulter’s management. 

Police have earlier confirmed they were not notified of his harassment of McDonald. 

Boulter pleaded guilty to murdering McDonald in November and was sentenced today in the High Court at Christchurch by Justice Owen Paulsen. 

Members of McDonald’s family and their supporters packed the courtroom’s public gallery. 

Montgomerie was also in the courtroom to see her attacker sent to prison for life. 

The hearing began with four of McDonald’s family reading Victim Impact Statements. 

Teen describes mum’s ‘disgusting’ murder 

McDonald’s daughter was 17 when she was killed. She cannot be named for legal reasons. 

“I witnessed the attack on my mum and what I saw and heard that day has had a severe and ongoing impact on me,” she said. 

“The images, the injuries, and the screams come back to me without warning… the way my mum was taken from us was violent and disgusting, and the pain that I’ll continue to carry with me is something that nobody will ever understand. 

“My little brother was only seven years old at the time. I’m very worried about the lasting impacts that this has had and will continue to have on him. 

“Seeing our mum taken from us in such a violent way has caused trauma that will stay with us both forever. My mum was stabbed not only once, not twice, but 55 times all over her body, head, and her face - and I’m the one that has to live with those horrific visions.” 

Nathan Boulter appeared via AVL for sentencing at the Christchurch High Court. Photo / Chris Skelton / Pool 

The teen said that losing her mother had “taken away all of the future moments” the tight-knit pair should have shared. 

“She wasn’t there when I turned 18, she won’t be there when I graduate, get married or have children of my own. She won’t be there for my 21st birthday or any of these milestones,” she said. 

“These absences are consistent reminders of everything that has been taken from us. 

“My mum was such a beautiful, strong-minded woman. Now the only way I can see or hear my mum is through photos and videos.” 

McDonald’s death has affected “every part” of the teen’s life. 

“That day I didn’t just lose my mum - I lost my sense of security, safety and direction. My mum was my biggest support; she was the reason I kept going in life,” she said. 

“She guided me in the right direction and was the person I could talk to about everything. She gave me comfort, reassurance, and stability. Since she died, all of that is gone.” 

The teen said “nothing can undo the harm that has been caused” by Boulter, which was “profound and lasting”. 

McDonald’s flatmate - who was in the house with her two preschoolers when Boulter attacked - also spoke. 

“I heard a loud banging on the front door, I opened it to my niece and nephew, emotional crying and yelling, saying ‘mum is being stabbed’,” she recalled. 

“The shock and disbelief quickly turned to fight-or-flight mode. It took me a bit to get what they were saying… I pulled them both inside, and (her daughter) and I called the police. 

“The screams I heard will never ever leave my mind or sleep.” 

She said she had flashbacks and loud bangs or screams sent her “into a panic”. 

“My life will never ever be the same,” she said. 

“You not only took away a dearly loved mother, you took away a life that can never ever be replaced - all because you could not take no for an answer.” 

Flowers at the scene of McDonald's murder. Photo / George Heard 

McDonald’s aunty Lyn - her father Steve’s sister - spoke of her “anguish, heartbreak and shock” when she got the call about the murder. 

She said her brother “struggled to get the horrifying words out” but eventually told her “Chantal has been killed”. 

She said the impact on the family had been “gutwrenching” - in particular for her children 

“They not only witnessed Chan being viciously murdered and barbarically taken, but now they have no mum,” Lyn said. 

“I’ll never forget sitting with Chan when she was in her coffin and hearing the heartbreaking words from (her young son). He spoke to his granddad and said ‘wake Mummy up, she needs to wake up now’. 

“To explain to a seven-year-old child that his mummy will never wake up again, that she is in heaven now… would have been so hard. 

“And to watch (him) trying to understand what was being said was so sad.” 

She described the “heartbreak” of watching McDonald’s children spending their last moments with her. 

“Touching their mum, being in her presence in silence and writing her notes so she could take them with her into the spirit world should never have happened,” she said. 

“The emotional impact has taken a huge toll on each of us… The waves of emotions that have followed have been mammoth…. Physically trying to carry on with life has been extremely taxing.” 

Justice Owen Paulsen. Photo / Chris Skelton / Pool 

She said when McDonald died, “a huge part of Steve died as well”. 

“The humorous, quick-witted man disappeared; instead, a broken man sat in front of us,” she said. 

“None of us ever thought something like this would ever happen to anyone in our family. This has been a huge shock to us all. 

“Chantal was an amazing young woman full of life who had everything to live for. Her life was ripped from her far too soon. There’s not a day that passes where she is not on our mind. 

“I look at her photo… and the tears flow… but now I fully understand what she was facing - being stalked and harassed continuously because you couldn’t take no for an answer.” 

She said Boulter was “cold and emotionless” and she “felt so much anger”. 

“I can only hope you will be haunted by your actions for the rest of your life,” she said. 

“May you suffer the way you made our girl suffer.” 

Crown: Murder was brutal, depraved, callous 

Crown prosecutor Pip Currie sought a minimum non-parole period of 18 years for Boulter. 

She said his offending displayed significant “brutality, depravity, and callousness” as well as “calculated premeditation”. 

She said the horror was exacerbated because McDonald’s children were present when she was stabbed to death - and the attack was at her own home where she should have been safe. 

She described Boulter’s actions as “overkill”. 

“The offender stabbed Chantal 55 times… She was stabbed in the head, face, and arms. This was a brutal, prolonged attack,” she said. 

“It was an extremely determined assault. It was designed to be deadly and there was an unnecessary level of violence - and consider perhaps the length of time that would be required to carry out that many blows.” 

She noted that McDonald was “in the process of locking herself in” to her property when Boutler struck. 

“Ironically… to protect or prevent this offender from gaining access,” she said. 

Crown prosecutor Pip Currie at sentencing for murderer Nathan Boulter in the High Court at Christchurch. Photo / Chris Skelton / Pool 

Currie said the fact that Boulter attacked McDonald, knowing her children were nearby, “elevates the cruel and callous nature” and reflects his “total insensitivity”. 

She was adamant the murder was planned - and detailed that position in court. 

“This offender had developed an unhealthy fixation on Ms McDonald. He had electronically harassed her after she terminated the relationship, calling her nearly 600 times over a two-week period,” she said. 

“The day before the murder… he purchased not only the weapon but also... concealed himself near her address and lay in wait for her. 

“He must have, at the very least, turned his mind to harming her from as early as the 14th of July when those texts were sent… these were effectively taunting.” 

She said in the lead-up to the stabbing, Boulter’s thoughts were “simmering regarding killing her”. 

“Then, there’s the hiding, waiting for her to come home…. a far cry from a spontaneous reaction,” she said. 

“He has thought about it… He has worked out the best approach… to ascertain when she would be at the most vulnerable to attack. 

“This obsessive type behaviour which is seen and referred to elsewhere and increasing this report, leads to a very clear inference that this is someone who has thought about and planned and focused on what action he’s going to take.” 

Currie said the “trauma and harm that flowed on” from McDonald’s death was clear. 

Boulter’s lawyer Philip Shamy disagreed with the Crown that the “preceding threats and harassment” reflected premeditation. 

He said the behaviour demonstrated an “unhealthy fixation with the victim” and while it was “more than likely an intention to frighten the victim” it did not reflect an intention to kill. 

“I am forced to say that death occurred relatively rapidly… This is not a case where there has been a prolonged torture or cruelty in terms of the homicide,” he said. 

He sought a minimum non-parole period of 14 years. 

He asked Justice Pauslen to consider Boulter’s personal circumstances. 

He said the killer had spent time in more than 40 foster homes as a child and suffered abuse in state care. 

He also had documented mental health issues “around schizophrenia, multiple personality (and) personality disorders. 

“Mr Boutler instructs me that he has struggled to obtain appropriate treatment for that,” he said. 

“And in the lead up to this horrific crime, Mr Boulter was struggling to find assistance. That is not put forward, however, as any form of excuse - nor is it put forward other than background as to what was happening to Mr Boulter at the time. 

“Things do not bode well for Mr Boulter. There are not a lot of redeeming features - I accept that. And on the face of it, Mr Boulter is a dangerous man.” 

Life in prison: Boulter’s sentence delivered 

Justice Paulsen sentenced Boulter to life in prison and ordered him to serve 17 years before he is eligible for parole. 

He said Boulter had 50 previous convictions and had been subject to 42 sentences of imprisonment from 2006 to 2025. 

The murder was a significant escalation to his previous offending. 

“There is a pattern of unhealthy fixations with ex-partners, with extreme electronic harassment escalating to threats of violence - and I note that legal sanctions including imprisonment and the imposition of specific releases have not prevented further serious offending,” Justice Paulsen said. 

“Your risk of reoffending and the risk you pose to the community are considered to be very high.” 

Justice Paulsen said there was “no evidence” before him to suggest what Boulter’s true mental state was at the time of the offending and whether there was any causative link to the murder. 

He said Boulter did not engage with pre-sentence report writers. 

“The report records that you have complex mental health issues, and since your remand, you have shown periods of disruptive behaviour as well as periods of compliance,” he said. 

“The report... notes your risk of violent offending is linked to your mental stability and that your refusal to take mental health medication has contributed to some previous offending. You also have a history of substance abuse. 

“However, it is unknown whether the state of your mental health or substance use contributed to this offending, and it is noted that you have had dealings with community mental health services for many years and you are aware of processes to access help you require.” 

Justice Paulsen said McDonald’s murder was a “brazen frenzied attack in public with a high level of violence”. 

“She was at her home, where she was entitled to feel safe,” he told Boulter. 

“She was unarmed, she did nothing to provoke you... this displays a brazen level of callousness... signifies a high level of brutality. 

“Ms McDonald was a loved mother, daughter, niece, and friend whose life should not have been taken that day,” said Justice Paulsen. 

“No sentence that I impose can make up for the loss of her life and the continued loss experienced by those who loved her. 

“The trauma suffered by Ms McDonald’s children and witnessing their mother’s death in such a manner will have been immense. 

“They will live with that their entire lives, and of course they have been robbed of the opportunity to grow up and share their lives with their mother.” 

Police acknowledge sentence 

After sentencing Detective Senior Sergeant Karen Simmons spoke about the case. 

“Today’s sentence will never bring Chantal back, or end the devastating sense of loss inflicted on her loving family,” she said. 

“There is no prison term that will ever make up for what happened to Chantal or the profound sense of loss her loved ones have had to endure. 

“However, today brings a small comfort in knowing the community will be protected from a violent, controlling and pathetic gutless coward who so needlessly took Chantal’s life.” 

Simmonds said Boulter’s decision not to appear in court in person and “face Chantal’s family” was “extremely disappointing”. 

“Chantal was a much-loved and devoted mother, daughter, sister and friend,” she said. 

“She was regarded as a vibrant and special person to all who knew her, which makes her loss even harder to bear for those who were lucky enough to know her. 

“We are continuing to provide support for Chantal’s family as they navigate life without her.” 

Simmonds said the family had been “extremely dignified” throughout the court process. 

“And I commend them for that,” she said. 

“They are appreciative of the support they have received, but request privacy. 

“I want to thank all of the police investigators, staff, and the Crown prosecutor who dedicated themselves to getting justice for Chantal. 

“They have worked relentlessly to bring this case to court and hold Chantal’s killer accountable for his horrendous crime.” 

“Frenzied”: The murder of Chantal McDonald 

The court heard earlier that Boulter and McDonald were in a brief relationship from May 2025. 

She ended it when he was recalled to prison and told him she did not want any further contact with him. 

Police said Boutler then “developed an unhealthy fixation” with McDonald. 

When he was released from prison, he began a “significant electronic harassment” of McDonald, including 581 calls to her between the 7th and 20th of July. 

Boulter used multiple cell phone numbers and social media profiles to “harass, stalk, and threaten” the woman. 

He sent her messages including “Ima chop u down to nothing hoe put u on the level narcissistist hoe” and “one two guess who’s coming for you! Your lack of human compassion and empathy will be the death of you one day soon my Lil hoe! Xxx” 

Nathan Boulter appears at the High Court of Auckland. Photo / NZH 

McDonald was terrified and began locking her front gate with a padlock to keep herself safe. 

She told family and friends about the threats. 

She tried to ignore him and did not contact him at all. 

On July 22, Boulter went to a hunting store in Christchurch and purchased a 19cm pig-sticker knife. 

The next night, he went to the street where McDonald lived. He hid behind a tree across the road from her house and “lay in wait”. 

McDonald arrived home with her children at 7.15pm. 

Boulter “crept” across the road and as McDonald walked back to close the gates behind her leapt out and attacked her with the knife. 

Her terrified children ran inside the house to safety as Boulter carried out a “frenzied” attack, stabbing McDonald 55 times. 

“The wounds were significant and included multiple trauma wounds to the head and face, causing extensive damage,” said the police summary of facts. 

“There were self-defence wounds around her hands and arms as she tried to protect herself. 

“There were further wounds all through her back and torso as well as through her knees. 

“Her injuries were so significant that she died within minutes.” 

Boulter left the scene and walked into a nearby house occupied by a family he did not know. 

He went inside and placed the murder weapon on the kitchen bench. 

He was told to leave, and he went out to the driveway and called his stepfather, then the police, confessing to both that he had just killed McDonald. 

“I just killed her now, I stabbed her to death, I f**ked up, bro, I need you guys to come get me, I just killed her bro,” he told police. 

Boulter was arrested soon after. He refused to be interviewed by the police. 

By then, the killer already had a lengthy history of offending against women. 

Nathan Boulter in the Auckland District Court following the incident on Great Barrier Island, Auckland. Photo / NZPA 

Boulter was subject to release conditions at the time of the murder. He had been released from prison on July 7, 2025. 

When he was released, Corrections said it worked with police in a “multi-agency group” to monitor his “risk and his compliance with his conditions”. 

As part of the Corrections “communicated and worked with relevant agencies, including police”. 

A review of Boulter’s management and monitoring has been completed - but will not be published for some time. 

“Immediately after the offending, Corrections commissioned a review into this offender’s management to identify any areas where we could strengthen our practices,” said communities, partnerships and pathways director Glenn Morrison. 

“Part of this includes how Corrections communicated and worked with relevant agencies, including police. 

“A Coroner’s inquiry into this matter is expected to take place once all criminal proceedings are complete, and Corrections’ review into this offender’s management is expected to form part of this inquiry. 

“We don’t want to compromise these proceedings in any way and for this reason, it would not be appropriate for Corrections to provide further information on this matter at this time.” 

Morrison said the Coroner agreed with the decision not to release the findings. 

“Last week senior Corrections staff, along with police, met with family members to offer our condolences and answer, where possible, any questions they had,” he said. 

“Out of respect their privacy, we won’t be providing further details of that meeting. 

“We know they will rightly still have many questions, and the Coroner’s inquiry will form an important part of addressing these questions.” 

Morrison offered condolences for everyone who knew and loved McDonald. 

“Our thoughts remain with the family and friends of the victim who was tragically murdered,” he said. 

“No family should ever have to experience the unimaginable pain brought about by the serious and devastating offending of Nathan Boulter. 

“I also want to acknowledge the victims of Mr Boulter’s previous offending, who may have found the news of his most recent crimes incredibly distressing. 

A terrifying ordeal on Great Barrier Island 

One of those victims was Nortessa Montgomerie, who was in court to see him jailed today. 

In January 2011, Boulter subjected his ex-partner Montgomerie, then 21, to physical attacks and terrifying threats over 38 hours after he bashed her unconscious and dragged her from her father’s home on Great Barrier Island. 

Montgomerie’s ordeal only ended when she managed to convince Boulter that she wanted to leave the island with him. Police said in doing that, she saved her own life. 

Boulter pleaded guilty to nine charges, including kidnapping and wounding with intent and was sentenced to eight years in prison. 

Montgomerie was in court today to see Boulter sentenced for murdering his most recent ex. 

In 2010 Boulter and Montgomerie were in a relationship and living together in Southland. 

He was charged with assaulting her after two separate incidents in September and October. 

Boulter was released on bail and was ordered not to have any contact with his victim – and to remain at his approved address in Southland. 

To avoid any further contact with her abuser, Montgomerie moved back to Auckland. 

On Boxing Day, Boulter breached his bail conditions and travelled to Auckland to try to find Montgomerie. 

On January 17, Boulter booked a one-way ferry ticket to Great Barrier Island under a false name. He arrived at 11.30am and made his way to Montgomerie’s father’s home. 

Police and members of the local community took part in a massive search for Nortessa Montgomerie. Photo / Natalie Slade 

He waited until it was dark and then entered the house and hid under Montgomerie’s bed. 

When Montgomerie went to bed, Boulter struck. He attacked a man staying with her on the back of the head with a hard object. 

Montgomerie begged Boulter to stop and in response, he hit her in the head. 

He hit the man repeatedly until he was unconscious and then chased after Montgomerie, who had run for help. 

He caught the 21-year-old and dangled her over a balcony by her leg and hair. He dragged her back up and rendered her unconscious by punching her in the back with his fist and kneeing her in the head. 

Armed with “a weapon resembling a thistle grubber” Boulter took Montgomerie from the house. 

Over the next day, during a fierce storm, Boulter held Montgomerie – wearing only a singlet and pyjama bottoms – in isolated bush. 

“At times you dragged her across undulating terrain in the bush … you abused her physically over this period. That abuse included physical attacks and strangulation that led to serious injuries. Your intent in doing so was to cause really serious harm to her,” said Justice Paul Heath Boulter’s sentencing. 

“After all of that, Ms Montgomerie was able to persuade you to dispose of a weapon by throwing it into a stream and to walk together towards the wharf to escape. Later in the day, searchers located the two of you. Ms Montgomerie’s ordeal finally came to an end.” 

Montgomerie suffered haemorrhaging to both eyes and a brain bleed from strangulation as well as bruising and swelling to her head and body and abrasions to her feet. 

Her friend suffered a fractured skull at the front of the head and bruising and swelling to the rest of his body. 

Police leading Nathan Boulter in handcuffs from a police launch at Mechanics Bay after his arrest on Great Barrier Island. Photo / Michael Craig 

Justice Heath said Boulter’s offending “involved a pre-conceived plan to travel almost the full length of this country to confront” his victim. 

“At the time, you were on bail in respect of domestic violence charges that had been laid in Invercargill. It is fair to say that nobody could have foreseen the trouble to which you went to meet up with Ms Montgomerie, in contravention of your bail conditions,” he said. 

“You then embarked on what can only be described as a course of conduct over a protracted period of time during which extreme physical violence was inflicted on Ms Montgomerie.” 

Boulter wrote letters to his victim but Justice Heath said he was “unsure about the degree of insight” the offender actually had into the harm he caused. 

“I have concerns about your inability to empathise adequately with your victims,” he said 

In July 2020, he was locked up after visiting a woman’s home, taking photos and, over the course of a single day, calling her 300 times and leaving more than 100 voicemail messages. 

In 2020, Boulter was back before the courts after offending against a second woman. 

The woman was a friend of Boulter’s sister in Southland who he started messaging and soon became obsessed with. 

He became aggressive and threatening, he stalked her, and he threatened to kill her. 

On one occasion, he went ot her home and later threatened his sister that he would return with a sawn-off 

On another occasion, he assaulted the woman and “advised her to kill herself”. 

Boulter was sentenced to three years and two months on seven charges of threatening to kill, contravening a protection order, assault with intent to injure and causing harm by digital communication. 

Dangerous man refused parole repeatedly 

He was refused parole a number of times – including when the board learned he had not undertaken any rehabilitation programmes in relation to his offending. 

But by April 2023, Boulter managed to convince the board that he could be released safety back into the community. 

Parole Board panel convenor Mary More noted Boulter’s “serious” conviction history. 

Alongside the Montgomerie kidnapping and stalking, there were a raft of convictions for “other violence, kidnapping and burglary”. 

Despite his dark past, More said Boulter’s parole assessment report stated he had “positive behaviour”. 

Nathan Boulter appearing at the Auckland District Court in 2011. Photo: NZPA / David Rowland 

“And he has said that he is determined not to do this again,” she said. 

The board heard Boulter planned to live with his mother and had the support of his family, that he had “insight into his mental health” and “knows when he is unwell and the impact on his behaviour”. 

More said Boulter “spoke very well” about “his warning signs”, including “substance abuse and going into an intimate relationship”. 

She noted that Boulter had just five weeks left of his sentence, so if the board wanted to impose any conditions at all it had to grant his release. 

If he served the full sentence, he would leave prison a free man with no conditions or monitoring. 

“The board considers that any undue risk Mr Boulter poses can be met by way of special conditions,” she said. 

Those conditions included two months of electronically monitored residential restrictions and taking his medication. 

For six months, Boulter was ordered to live at an approved address, not to consume alcohol or illicit drugs, not to contact any victims of his offending and to disclose all details about any intimate relationship which commences, resumes, or terminates to his probation officer. 

He was not subject to any parole conditions when he murdered McDonald. 

Anna Leask is a senior journalist who covers national crime and justice. She joined the Herald in 2008 and has worked as a journalist for 20 years with a particular focus on family and gender-based violence, child abuse, sexual violence, homicides, mental health and youth crime. She writes, hosts and produces the award-winning podcast A Moment In Crime, released monthly on nzherald.co.nz