Criminal conviction and sentencing statistics

Criminal conviction and sentencing tables (for both fiscal and calendar years) are available on NZ.Stat – our free web tool for creating, finding, customising, and downloading datasets. These tables include data on:

• Adults convicted in court by sentence type – most serious offence
• Adults with finalised charges in court – most serious offence
• Charges finalised for adults by offence type
• Children and young people with finalised charges in court – most serious offence
• Children and young people given an order in court – most serious offence.

About the data

This page gives the source of the data in the criminal conviction and sentencing tables and explains what statistics have been included or excluded. It also provides important information about data quality, the effect of appeals, and describes situations where published data may be revised.

Source

The criminal conviction and sentencing tables contain data from the Ministry of Justice's statistical reporting datasets. The data were sourced from the courts' operational data systems. The Law Enforcement System (formerly known as the Wanganui Computer and used by justice agencies from the late 1970s until 2005) was used as the source of these data up until 2003. From 2004, the data have been sourced from the Ministry of Justice's Case Management System.

Identifying details have been removed, and data have been aggregated to ensure information is anonymous. For Child and youth prosecution statistics data have been randomly rounded to base 3.

Inclusions and exclusions

Adults (aged 17 and over; or from 1 July 2019 onwards aged 18 and over) or charges against adults are counted in the Adults with finalised charges - calendar year, Adults with finalised charges - fiscal year, Adults convicted - calendar year, Adults convicted - fiscal year, Charges against adults – calendar year, and Charges against adults – fiscal year tables.

Children and young people (aged 10 to 16 or from 1 July 2019 onwards aged 10 to 17 ) are counted in the Children and young people with finalised charges – calendar year, Children and young people with finalised charges – fiscal year, Children and young people given an order – calendar year, and Children and young people given an order – fiscal year tables. Read how children and young people are defined.

Quality of data

Data in the tables has been simplified and categorised for high-level analysis. Like all operational data, it could contain anomalies that would not affect its day-to-day use but could cause errors for statistical analysis.

For example, incorrect coding of some data items may not affect how charges or cases progress through the court system. However, coding errors can impact on how the data is categorised and counted when reporting statistical summaries.

The chance of such anomalies occurring is minimal. There are rigorous processes in place to verify, and ensure that, operational data is accurate and therefore suitable for statistical analysis.

Effect of appeals

Data from the previous two years should be considered provisional as appeals can influence charge outcomes and sentences. Any comparison between previous versions of the criminal conviction and sentencing tables can show differences caused by these appeal changes.

Re-sentencing data needs to be treated with caution as it may not have been reported in all cases.

Revision of published data

Changes in legislation, improved analysis methods, corrections to earlier data or changes in classifications may mean that the statistics are slightly different to those published in previous years. For example, a conviction may be overturned on appeal or a sentence changed, which would affect conviction and sentencing statistics. Each year’s release recalculates figures from previous years and may not be comparable with previous releases.

Conviction and sentencing statistics were compiled using cases through to the 2008 release of the statistics, but from 2009 onwards were released on the basis of counting charges and people. The new approach was adopted after extensive consultation with stakeholders who considered it to be more consistent, intuitive, and easier to understand.

The tables available here contain data from the Ministry of Justice's statistical reporting datasets. The data were sourced from the courts' operational data systems. The Law Enforcement System (formerly known as the Wanganui Computer and used by justice agencies from the late 1970s until 2005) was used as the source of these data up to 2003. From 2004, the source of these data was the Case Management System (CMS) of the Ministry of Justice.

Adults convicted in court by sentence type - most serious offence fiscal or calendar year

The ‘Adults convicted’ table contains the number of adults (aged 17 and over; or from 1 July 2019 onwards aged 18 and over) with convicted charges in a criminal court during a fiscal or calendar year.

This data only shows the most serious offence per adult per year. Where an adult has more than one offence in a year, the data shown (e.g. offence type, outcome, sentence) relates to the most serious offence.

This means that using data counting the most serious offence in isolation can result in an undercount of the number of adults charged with specific offence types (e.g. for illicit drug offences, out of approx. 6000 people charged in 2016, only half had illicit drug offences as their most serious offence).

Note that the size of undercounts will vary depending on the offence or charge outcome type.

For more representative information on specific offence or charge outcome types refer to the data tables on the Ministry of Justice website.

'Multiple ethnicity' information is used in this table. This means for each ethnicity an adult is counted once per fiscal or calendar year (e.g. they may be counted in both European and Māori). As some adults have multiple recorded ethnicities, this will result in the sum of ethnicities being greater than the total number of people each year.

Identifying details have been removed and the data have been aggregated to protect individuals' privacy.

From 29 April 2016, we source courts data from the new Enterprise Data Warehouse (EDW), rather than the justice sector data warehouse (ISIS) used over recent years. Changes in data processing may cause small differences if you compare current output with similar results produced before 29 April.

Adults with finalised charges in court – most serious offence fiscal or calendar year

The ‘Adults prosecuted’ table contains statistics for 1980 onwards about adults (aged 17 and over, or from 1 July 2019 onwards aged 18 and over) with charges finalised in criminal courts during a fiscal or calendar year.

This data only shows the most serious offence per adult per year. Where an adult has more than one offence in a year, the data shown (e.g. offence type, outcome, sentence) relates to the most serious offence.

This means that using data counting the most serious offence in isolation can result in an undercount of the number of people charged with specific offence types (e.g. for illicit drug offences, out of approx. 6000 people charged in 2016, only half had illicit drug offences as their most serious offence).

Note that the size of undercounts will vary depending on the offence or charge outcome type.

For more representative information on specific offence or charge outcome types refer to the data tables on the Ministry of Justice website.

Identifying details have been removed and the data have been aggregated to protect individuals' privacy.

From 29 April 2016, we source courts data from the new Enterprise Data Warehouse (EDW), rather than the justice sector data warehouse (ISIS) used over recent years. Changes in data processing may cause small differences if you compare current output with similar results produced before 29 April.

Charges finalised for adults by offence type fiscal or calendar year

The ‘Charges prosecuted against adults’ table contains statistics for 1980 onwards about the number of charges finalised against adults (aged 17 and over, or from 1 July 2019 onwards aged 18 and over) in criminal courts during a fiscal or calendar year.

Identifying details have been removed and the data have been aggregated to protect individuals' privacy.

From 29 April 2016, we source courts data from the new Enterprise Data Warehouse (EDW), rather than the justice sector data warehouse (ISIS) used over recent years. Changes in data processing may cause small differences if you compare current output with similar results produced before 29 April.

Children and young people with finalised charges in court – most serious offence fiscal or calendar year

The ‘Children and young people charged’ table contains statistics for 1992 onwards about children and young people who were charged in a criminal court during a fiscal or calendar year for their most serious offence in that year.

This data only shows the most serious offence per child or young person per year. Where a child or young person has more than one offence in a year, the data shown (e.g. offence type, outcome, most serious order/sentence) relates to the most serious offence.

This means that using data counting the most serious offence in isolation can result in an undercount of the number of people charged with specific offence types (e.g. for illicit drug offences, out of approx. 6000 people charged in 2016, only half had illicit drug offences as their most serious offence).

Note that the size of undercounts will vary depending on the offence or charge outcome type.

'Multiple ethnicity' information is used in this table. This means for each ethnicity a person is counted once per fiscal or calendar year (e.g. they may be counted in both European and Māori). As some people have multiple recorded ethnicities, this will result in the sum of ethnicities being greater than the total number of people each year.

A modified version of Statistics NZ's method of base 3 random rounding has been applied to protect the confidentiality of individuals. In the standard version, all counts are randomly rounded up or down to one of the adjoining multiples of 3 (e.g. a count of 5 would be displayed as either 3 or 6, and a count of 1 would be displayed as either 0 or 3).

In the modified version, 1s and 2s are always rounded up to 3. Only zero counts are displayed as 0.

Identifying details have also been removed, and data have been aggregated.

From 29 April 2016, we source courts data from the new Enterprise Data Warehouse (EDW), rather than the justice sector data warehouse (ISIS) used over recent years. Changes in data processing may cause small differences if you compare current output with similar results produced before 29 April.

Children and young people given an order in court - most serious offence fiscal or calendar year

The ‘Children and young people given an order’ table contains statistics for 1992 onwards about children and young people with a ‘Youth court proved (order under s283)’outcome or who are convicted and sentenced in the District or High Court during a fiscal or calendar year.

This data only shows the most serious proved offence per child or young person per year. Where a person has more than one proved offence in a year, the data shown (e.g. offence type, outcome, order/sentence) relates to the most serious proved offence.

Note that statistics for children and young people with orders/sentences use a slightly different counting rule to children and young people with proved charges. The most serious ‘Youth court proved (order under s283)’ or ‘Convicted and sentenced in adult court’ charge outcome and order/sentence is counted regardless of whether the charge was for a non-imprisonable traffic offence heard in the District Court or not.

This means that using data counting the most serious offence in isolation can result in an undercount of the number of people charged with specific offence types (e.g. for illicit drug offences, out of approx. 6000 people charged in 2016, only half had illicit drug offences as their most serious offence).

Note that the size of undercounts will vary depending on the offence or charge outcome type.

'Multiple ethnicity' information is used in this table. This means for each ethnicity a person is counted once per fiscal or calendar year (e.g. they may be counted in both European and Māori). As some people have multiple recorded ethnicities, this will result in the sum of ethnicities being greater than the total number of people each year.

A modified version of Statistics NZ's method of base 3 random rounding has been applied to protect the confidentiality of individuals. In the standard version, all counts are randomly rounded up or down to one of the adjoining multiples of 3 (e.g. a count of 5 would be displayed as either 3 or 6, and a count of 1 would be displayed as either 0 or 3).

In the modified version, 1s and 2s are always rounded up to 3. Only zero counts are displayed as 0.

Identifying details have also been removed, and data have been aggregated.

From 29 April 2016, we source courts data from the new Enterprise Data Warehouse (EDW), rather than the justice sector data warehouse (ISIS) used over recent years. Changes in data processing may cause small differences if you compare current output with similar results produced before 29 April.