10 Data definitions and groupings

10.1 Major management category

The offender inventory system enforces a one-day-one-status requirement on each offender so that each offender's timeline is partitioned into discrete and non overlapping episodes of management. Major Management Categories are defined with a "trumping order". The order of precedence in the hierarchy of management is; sentenced prison > remand > home detention > community detention > intensive supervision > supervision > community work, allowing the most expensive or significant management category to be determined on any day. Further, the rule also allows examination of the balances and transitions from one category to another category in a way that assists in analysing Corrections' business, and offenders' careers.

One of the features of the resulting timeline data set is that it provides for analysis of offender flows and balances such that opening balances always equal closing balances and there is certainty that no change to an offender's status has been inconsistently treated. Should an offender status change be overlooked then the offender will soon become obvious as being inappropriately classified. One of the consequences of this is that the numbers do not necessarily provide all the detail covered in other reports.

The full table with rank order for "major management categories" can be found here. An overview of the descriptions used is given below. It should be noted that the definitions are necessarily loose to accommodate a span of history with changing terminology and legislation.

Glossary of major management category terms

Term used

Meaning an episode of management where:


The offender is sentenced to a "life" or "preventive detention" custodial episode with no set release date; any release requires an order of the Parole Board.

Long term

The offender is sentenced to a custodial episode of fixed length, with the longest sentence chain (after taking into account cumulative and concurrent directives) being greater than two years. Currently the law requires these longer-term sentenced offenders to serve at least one third of the imposed term, though they can be held until the end of the imposed term, at the Parole Board's discretion

Short term

The offender is sentenced to a custodial episode of fixed length, with the longest sentence chain (after taking into account cumulative and concurrent directives) being less than or equal to two years. Currently the law requires shorter-term sentenced prisoners to be released after serving exactly half of the imposed sentence length.

Other custody

Is a catch-all category designed to ensure that any anomalous data indicating a custodial sentence is not lost.


An individual may be remanded in custody by the court and held in police cells, court cells, psychiatric facilities or corrections facilities. The remand period is normally short and specific or until a specified Court day for trial or for sentencing. It is very common for remanded individuals to have multiple charges on each remand warrant, with new and successive remand warrants issued during the course of a single episode on remand. Remand warrant data is available for analysis only from mid-1998 onwards.

Home detention orders (before October 2007)

Home detention is an electronically monitored and supervised restriction to live and stay at a specified address. Home detention is managed by the Community Probation Service.

Up until October 2007 home detention was ordered by the Parole Board and there were two conceptually different types of such orders. "Back-end home detention" was ordered to manage an offender's return to the community after a long-term prison sentence. "Front end home detention" was ordered as a means of serving a short term prison sentence, if the sentencing judge had granted leave for an application to be made to the Parole Board.

Home detention sentences (from October 2007)

From October 2007 the new sentence of Home Detention became a reality. In implementation home detention sentences are almost identical to the home detention orders (described above) but are sentences of the Court rather than orders of the Parole Board.

Parole with full residential conditions

(from October 2007)

Also from October 2007 the Parole Board became able to order "Parole with full residential conditions". In this document "Back-end home detention orders" and "Parole with full residential conditions" are treated as the same regime and described as "Long term prison released to home detention".

Community detention

(from October 2007)

From October 2007 the new sentence of Community Detention became a reality. This is conceptually an electronically monitored curfew.

Extended supervision

Offenders may be subject to an order, imposed by the court and with conditions set by the New Zealand Parole Board, by which they are managed by the Community Probation Service. The order can apply for up to 10 years following a finite term of imprisonment. High and long-term risks posed by some sex offenders in the community are the primary target of this order.


Prison-sentenced offenders may be ordered to be released to parole management by the New Zealand Parole Board. Parole requires that the offender meets regularly, and works closely with a Corrections probation officer, who ensures that special conditions imposed by the Board are fulfilled.

Post release conditions

Prison sentenced offenders may have post release conditions imposed by the judiciary at the time of sentencing. Such conditions are overseen by a probation officer.

Intensive supervision

(from October 2007)

From October 2007 the new sentence of Intensive supervision became a reality. This sentence is similar to supervision described below but involves a higher level of restriction and supervision and more complex special conditions and management requirements.


Offenders sentenced to supervision report regularly to a probation officer and, if ordered by the court, fulfil special conditions designed to address their risk of further offending. Supervision may include in-depth, focused interventions such as rehabilitative programmes, reintegration services, or counselling that addresses their offending. In October 2007, the maximum duration of supervision was cut from 24 to 12 months.

Community work

Offenders sentenced to community work complete a prescribed number of hours of work within the community. Community Work sentences came into effect with the Sentencing Act 2002, and provide for a degree of reparation to the community.

Other Community

Refers to all community sentences other than supervision or community work. This covers all predecessors of community work including community service and periodic detention sentences.

Discretionary release-eligible

Refers to offenders who are prison sentenced at the time being considered, but for whom a Parole Board (New Zealand Parole Board or its predecessors) had discretionary power to order release from the imprisoned episode, but had not yet done so. At 30/06/2009 the New Zealand Parole Board had the following discretionary powers:

  • to grant parole (possibly with full residential conditions among other ordered conditions) to long-term prison sentenced offenders who had served at least 1/3rd of their imposed term or any specified minimum term (whichever is the greater)
  • to grant (lifetime) parole to life sentenced offenders who had served at least ten years or any specified minimum term (whichever is the greater)
  • to grant parole to preventive detention sentenced offenders who had served at least five years or any judicially specified minimum term (whichever is the greater)

Never sanctioned

These individuals have never previously been managed by Corrections; they may however have convictions which were sanctioned with fines or other lower-level penalties, or they may have previously been held in custody remand but later released without conviction. Approximately 35% of new management episodes each year involve individuals who have no previous correctional history.

Offender pool

Has had at least one previous episode of management under Corrections within the last ten years. The majority of new starts under correctional management each year are individuals from the Offender Pool.

Aged out

Has had at least one previous episode of management under Corrections, but none within the last ten years. Only a small number of such individuals return to correctional management each year (less than 5% of all new starts), so most in this category can be considered to have desisted.

10.2 Gender

Corrections' databases record four gender types: Male; Female; Unknown and Indeterminate. In some cases the "Unknown" and "Indeterminate" gender groups have been amalgamated or dropped from display when numbers are insignificant.

10.3 Age

Age data in this collection is generally calculated from the recorded date of birth until the date of interest. Where this calculation has resulted in anomalous results, such as negative numbers, or less than fifteen years old, then the offender is grouped with those of an "Unknown" age.

10.4 Preferred ethnicity

In determining "preferred ethnicity", individuals are associated only with their most recent self-identified "preferred ethnicity" as recorded in Corrections' database and grouped according to Statistics New Zealand ethnicity groupings (see ethnicity groupings here).

Where no ethnicity is available from Corrections' data, the data is then supplemented with historical data from the Ministry of Justice (MoJ) data warehouse. The MoJ data warehouse in turn inherited this ethnicity data from the Law Enforcement System (LES) running since mid-1970s. The LES supplementary data was apparently based on Police officers' assessment of the offender's ethnicity. The bulk of the data (and all of it since 1998) comes from Corrections' database. Even with the inclusion of the supplementary data, there are significant numbers of individuals with unknown ethnicity prior to 1998. As far as the author is aware the missing ethnicity data is an artefact of the data collection and import processes of the time, and all ethnicities would have been equally impacted.

The "preferred ethnicity" approach used here partly follows Statistical Standard for Ethnicity 2005, and differs from the standard in the following ways:

  • It does not multiple-count individuals who have identified with multiple ethnic groups and instead places them only in their "preferred" ethnic group
  • It has not collected the ethnicity data in the way prescribed in the 2005 standard. Instead, the ethnicity data results from an amalgam of historical methods relating to the time the data was collected, the agency doing the collecting and the standard of the day.

10.5 Multiple ethnicity

Corrections ask for ethnicity information at each reception and offenders are associated with all their most recent self-identified ethnicities. This information is recorded in Corrections' database and grouped according to a Statistics New Zealand ethnicity mapping. This means that it is possible for an individual to be counted in multiple ethnic groups at one time. Note that this differs from the "preferred ethnicity" approach described above where individuals are only associated with a single ethnic group.

The "multiple ethnicity" approach is only used in this report for graphs showing snapshots of age, gender and ethnicity groupings when being compared against national population data. This provides a best match in methods for comparing the two data sets. However, an exact match with the methods prescribed in the Statistical Standard for Ethnicity 2005 has not been possible as Corrections' ethnicity data results from an amalgam of historical methods relating to the time the data was collected, the agency doing the collecting and the standard of the day.

10.6 Offence category; Charge category

The method used in this report for categorising an offender management episode by offence category is similar to a method commonly used by the Ministry of Justice. For each episode of management only offences relating to that episode are considered. Thus, for recalled offenders this includes the offences they are recalled upon as well as any new offences. The most serious offence is selected according to the Ministry of Justice seriousness score. The most serious offence is then mapped to a descriptive offence category.

The Ministry of Justice offence seriousness score is described below:

"A seriousness of offence scale was originally developed by the Policy and Research Division of the Department of Justice in 1991, and has been updated about every five years since then. The most recent update of the scale occurred in February 2005 by the Ministry of Justice. The updated scale gives imprisonable offences a score according to how serious judges have deemed each offence in terms of the use of custodial sentences over a specific time period.

The updated scale is based on court sentencing data for the period 2000 to 2004. The seriousness score assigned to each offence is the average number of days of imprisonment imposed on every offender convicted of that offence between 2000 and 2004, where the average is taken over both imprisoned and non-imprisoned offenders. Suppose, for example, that between 2000 and 2004 there were 100 cases of offenders convicted of a particular offence. Of these cases, 50 resulted in a custodial sentence, and the average length of the custodial sentences imposed on these offenders was 30 days. The seriousness score for this offence is (30 x 50/100), or 15.

Offences that became obsolete prior to 2000 were given the same score as any new similar offences, or a score was calculated based on sentencing data before 2000. Imprisonable offences for which there were convictions but no custodial sentences over the period 2000 to 2004, were given a seriousness rating slightly lower than the least of the offences already assigned a seriousness score (i.e. a score of 0.2). Non-imprisonable offences were assigned a seriousness score of zero"

Police offence codes and descriptions have been assigned to offence categories and can be inspected in detail here along with their associated Ministry of Justice seriousness scores. The categories used here are particular to this document but related to the Police offence code groupings. Some extra groupings are used here to assist in illustrating particular trends or relationships. For instance the age profiles for offenders grouped by "Homicides", "Assaults, abduction, threats" or "Robbery" are distinctly different so they have not all been grouped together as "Violence".

The table below gives general descriptions of the offence categories used in this report.

Offence group


Assaults, abduction, threats

Grievous assaults; Serious assaults; Minor assaults, Kidnapping and abduction; Intimidation and threats

Burglary, conversion, theft

Burglary; Car conversion; Theft

Driver licence and conduct

Disqualified driving; Manner of driving; Condition of driver; Condition of vehicle; Dangerous driving; Speeding; Vehicle licence and registration … and basically all traffic and transport law breaches other than Drunk and drugged driving

Drug, liquor, gambling

Drug, liquor and gambling offences (other than drunk and drugged driving)

Drunk and drugged driving

All alcohol and drug affected driving offences

Fraud, receiving

Fraud and receiving including breach of statutes type frauds such as illegal importing or tax evasion or benefit fraud where the offender derives an advantage or financial gain


Murder; Attempted murder; Manslaughter; Aiding suicide

Misc against good order

Group assemblies; Harassment; Obstructing; Inciting; Trespass; Breach firearm controls; Breach environment controls; Breach safety controls; Breach border controls; Breach behaviour and good management controls; Breach sentence etc.

Property damage and endangering

Arson; Wilful damage; Endangering; Aircraft high- jacking


Aggravated and non-aggravated robbery; Assaults with intent to rob; Compelling the use of a document

Sexual offences

Rape; Attempted rape; Sexual violation; Incest; Indecent Assault; Other indecency; Unlawful sexual connection