The criminal justice system in New Zealand is the collection of government agencies and institutions, including the police, courts, and correctional services that work together to uphold the law, prevent and respond to crime - and administer justice by investigating, prosecuting, and holding criminal offenders to account. The main functions of the system are to maintain social order, protect the freedoms and rights of individuals, ensure accountability for those who break the law - based on fair and impartial treatment - and to rehabilitate offenders. Criminal justice is distinct from criminal law, which defines what constitutes a crime and the penalties for it. It is also distinct from criminology, which focuses on understanding the causes of crime and the behavior of offenders.
However, the justice system is not the only contributor to social order in New Zealand. Egalitarian social norms, informal support networks of family, friends, and respect for cultural traditions play a more important role in maintaining a civil society. While governments tend to focus on 'law and order' issues, especially during election cycles, and use high-profile incidents to suggest that crime is out of control, surveys indicate that the vast majority of New Zealanders feel safe in their own homes.
International surveys such as the Global Peace Index and Transparency International consistently indicate that New Zealand is largely seen as corruption-free, and one of the safest and most peaceful countries in the world. However, because successive governments have succumbed to the pressures of penal populism, from the 1980s, New Zealand has high rates of imprisonment and recidivism compared with other western countries.
Despite the cyclical concerns about 'law and order,' the courts in New Zealand are generally seen as impartial and free of corruption. However, in the last few years, justice has been impacted by significant delays in cases getting to court. Concerns have also been raised about the quality of pre-sentence reports supplied to judges by the Corrections Department; and about the small number of specialist reports to assist judges at sentencing. In 2024, the current government stopped legal aid funding for cultural reports. These were seen as necessary to implement Te Ao Marama, an initiative of chief district court judge, Heemi Taumaunu, to introduce solution-focussed judging to all district courts. That initiative has now stalled, pending a review by the Ministry of Justice.
Despite the importance of providing fair and impartial treatment, a growing number miscarriages of justice have occurred in recent years. Concerns have been raised about the use of prison snitches, false confessions and tunnel vision in police investigations, but also about the inability or slow response of the appeal courts and the Ministry of Justice to turn these convictions around. The frequency with which the criminal justice system has been getting it wrong eventually led to the establishment of the Criminal Case Review Commission which is independent of the courts and the MOJ.
The justice system also has a very poor record when it comes to rehabilitating criminal offenders. The Corrections Department's prison based programmes have very little impact, generally reducing reoffending, on average, by less than 5%; as a result recidivism rates in New Zealand are high compared with other western countries. The Alcohol and Other Drug Treatment Court in Auckland is the only justice related intervention in New Zealand that makes a significant difference, reducing reoffending of graduates by 86% in the first 12 months after treatment.
Deterrence and the maintenance of social order
Section 8 of the Sentencing Act 2002 lists eight 'purposes of sentencing'. Seven of those purposes relate to denunciation, deterrence and holding the offender to account - all intended to impose social order. Only one purpose of sentencing is to assist offenders rehabilitate.Sentencing Act 2002
Social norms
Despite the political focus on 'law and order', the effectiveness of the justice system at deterring crime is influenced by multiple factors beyond law enforcement and sentencing. New Zealand's social order is maintained through a mix of egalitarian norms, community-mindedness, informal support networks of family, friends and respected others (including professionals such as doctors, lawyers, counsellors, government and local service agencies), and respect for cultural traditions.Anne Spellerberg, Framework for the measurement of social capital in New Zealand. Statistics NZ, 2001Manners and social behaviour, TeAra. The Encyclopedia of New Zealand,
The crime rate
As such, it is difficult to determine the role or impact of the criminal justice system in this process. One measure of its effectiveness might be the ups and downs of the New Zealand crime rate, which rose steadily during the 20th century peaking in 1992,Crime in New Zealand: 1996–2005, Statistics New Zealand but has declined considerable since then. However, the official crime rate is not necessarily a reliable indicator of the level of crime in society. The New Zealand Crime and Victims Survey (NZCVS) published by the Ministry of Justice, claims that only a quarter of all crime incidents are actually reported to the police. But this figure is based on answers to survey questions about victimization, rather than crimes that were reported to police, and may or may not meet the standard necessary for prosecution.New Zealand Crime and Victims Survey released, Ministry of Justice
International perspectives Global Peace Index: Perhaps the best indicator of how effective New Zealand is at maintaining social order is its position on the Global Peace Index issued by the Institute for Economics and Peace. In 2010 and 2011, New Zealand topped the index'Peace index ranks Canada 14th in world', The Canadian Press, 8 June 2010. - out of 149 countries - based on 23 indicators including corruption, violence, crime rates, military spending and access to primary education. On the 2025 Global Peace Index, New Zealand ranked 3rd in the world, just behind Iceland (1st) and Ireland (2nd). New Zealand consistently ranks among the most peaceful countries globally, reflecting high levels of safety, stability, and low crime rates.World's Most Peaceful Country 2025 Global Peace Index, Global Finance June 2025. Corruption Perceptions Index: Serious fraud is prosecuted by the Serious Fraud Office in New Zealand. New Zealand also ranks among the least corrupt countries in the world, consistently placing in the top tier of the Transparency International Corruption Perceptions Index (CPI). In the 2024 CPI, New Zealand scored 83 out of 100. This put use fourth in the world behind Denmark, Finland, and Singapore — after previously holding the top spot alongside Denmark for many years. This makes New Zealand a global leader in perceived public sector integrity, in comparison to most other countries.Analysis relevant to New Zealand from the Corruption Perceptions Index 2024, Transparency International, 2024
Comparative prison rankings Historically, politicians in New Zealand including from the current government, have assumed that longer prison sentences will deter crime or reduce reoffending. The current Corrections Minister, Mark Mitchell, has even stated a preference for scrapping short prison sentences in favor of longer ones.Mark Mitchell wants short prison sentences scrapped in hope of reducing reoffending, RNZ, 5 May 2025.
In July 2025, New Zealand's rate of imprisonment was 197 people per 100,000 population,World Prison Brief, New Zealand 31 March 2025 which is significantly higher than the OECD average. In Australia, the rate is 163 per 100,000; In England and Wales, the rate is 141 per 100,000; In Canada the rate is 90 per 100,000; In Finland its 52 per 100,000; and In Germany the rate is 68 per 100,000.World Prison Brief
Contributing factors: In other words, New Zealand's rate of imprisonment is well above most Western European and other developed nations. A number of factors in the justice system contribute to this high rate:
Policy and public attitudes: The prison population is largely driven by government policy and public attitudes toward crime and punishment, rather than actual crime rates.Long Term Insights Briefing, Justice Sector, December, 2022. Tougher sentencing and parole laws: Legislative changes, such as the Sentencing and Parole Reform Act 2010 and the Bail Amendment Act 2013, have increased the length of sentences and made it harder for offenders to get bail or parole. These policies were often introduced in response to high-profile crimes and public pressure, rather than evidence of effectiveness, and have not been shown to deter crime.Using evidence to build a better justice system: The challenge of rising prison costs. Office of the Prime Minister's chief science advisor, March 2018 Underlying social issues: Māori are disproportionately represented at every stage of the criminal justice system, as a result of systemic issues such as intergenerational trauma, marginalization, and institutional racism.They're our Whānau, University of Otago They make up 52% of the prison population despite being only about 15% of the general population. The majority of those in prison also have histories of abuse, mental health issues, and substance abuse. These underlying social issues are not adequately addressed by the justice system, leading to higher rates of offending and reoffending. Flawed rehabilitation programmes: Corrections Department rehabilitation programmes are largely ineffective at reducing reoffending (see Justice and rehabilitation below) and around 56.5% of people with previous convictions are reconvicted within two years of release, and 35.8% are re-imprisoned, which keeps the prison population high.Hāpaitia te Oranga Tangata, Ministry of Justice
The prosecution process Most crimes in New Zealand are prosecuted by the Police. However, approximately 81% of police prosecutors in New Zealand do not have a law degree, and only about 19% have legal qualifications.Under Investigation: A Review of Police Prosecutions in New Zealand's Summary Jurisdiction, Auckland University Law review, 2007
The most serious crimes are prosecuted by Crown Solicitors, which are private law firms appointed by the Governor-General. Crown Solicitors conduct prosecutions in Category 4 offences, which cover the most serious crimes like murder; schedule offences, which are listed offences such as aggravated robbery and manufacture of methamphetamine; and offences not listed in the Schedule but where the defendant elects a jury trial.Crown prosecutions, Ministry of Justice, Lawyers and service providers.
There is no centralised agency responsible for conducting prosecutions or making prosecution decisions in New Zealand. This lack of a centralized prosecution authority is unique compared to many common law countries.Introductory words from the Law Officers, Crown Law December 2024
Concerns about police acting as prosecutors Academics have expressed concerns that prosecutors who are trained police officers are unable to be fully independent or impartial. Officers in this role may struggle to be impartial due to occupational pressures, their loyalty to police colleagues and adherence to the police culture and worldview. Emeritus Professor, Andrew Ashworth, at Oxford University describes police culture as having a high level of police solidarity (involving strong support for colleagues' decisions and a 'blue code of silence'.) a macho image (involving an emphasis on physicality and supporting each other), rule flexibility (the idea that rules may need to be bent to get results), and a sense of mission (requiring officers to conduct themselves in the proper way - 'their way').