Introduction

Reducing re-offending is an important outcome objective for most correctional services. As such, measures of recidivism, particularly reconviction and re-imprisonment rates, are key indicators of those services’ performance.

The data presented here are based on the “recidivism index” (RI) methodology used in the Department of Corrections’ (“the Department’s”) annual reporting of reconviction and re-imprisonment. This method quantifies the rate of reconviction and re-imprisonment for specified sub-groups of offenders, over follow-up periods of defined length, after release from a custodial sentence or from the start date of a community sentence. Conviction and sentencing data is obtained from the Ministry of Justice’s Case Management System (CMS) database.

This report summarises patterns of reconviction and re-imprisonment amongst almost 5000 offenders who were released from prison during the 12 months period 1 April 2002 to 31 March 2003. The same cohort of offenders was the subject of a previous report in this series, which provided reconviction and re-imprisonment rates within a 36-months follow-up period 1. The current report provides similar data but now with a 48 months follow-up period: that is, figures represent any reconviction for an offence that occurred within 48 months of each individual offender’s release date (up to 31 March 2007) 2. The next report in the series (expected early in 2009) will give figures for a five-year follow-up.

Recidivism figures are produced for two potential outcomes: reconvictions leading to any sentence administered by the Department of Corrections (community-based or prison), and reconviction leading solely to a term of imprisonment. Imprisonment figures are generally considered the more critical of the two measures, as this outcome is associated with more serious offences and higher costs of sentence administration. Recidivism figures exclude reconvictions which do not result in sentences administered by the Department (fines, convicted and discharged, etc). All references in this report to reconvictions should be interpreted as restricted to convictions resulting in imprisonment or a community-based sentence

It is also important to note that most of the figures here represent any reconviction or re-imprisonment during the 48-month follow-up period: some of the individuals re-imprisoned may have had multiple, successive terms of imprisonment during that period. Some information on multiple re-imprisonments is given in respect of certain offence classes.

The figures below reveal important differences in the post-release re-offending behaviour of different sub-groups of offenders. Offender characteristics such as gender, age at release, ethnicity, offence type3, offender’s previous criminal history and age at first imprisonment are each examined with reference to reconviction and re-imprisonment. In addition to previous results, this report also summarises the frequency of re-imprisonments during the 48-month follow-up period for burglars, disqualified drivers and drink-drivers. It is intended that analysis of such patterns for other offence types will be provided in subsequent reports.

Recidivist offenders are a challenge both to criminal justice sector agencies and to society at large. Therefore, this report examined the entire reconviction data set for the current sample by dividing the population into two groups, “first-timers” and “recidivists”. A number of important findings emerge from this perspective on recidivist offenders.


1. Publication released in March 2007, “Reconviction Patterns of Released Prisoners” (A 36-months Follow-up Analysis).

2. The data set also included reconvictions on dates up to 30 June 2007 when the offence date was prior to 31 March 2007.

3.  As a great many offenders are sent to prison for multiple offences, offenders in this analysis are grouped according to the “most serious offence” (MSO) for which they were imprisoned on the original sentence. MSO rankings are determined from the Ministry of Justice Seriousness of Offence Scale, which orders offences in accordance with the average number of days imprisonment ordered by judges, for that specific offence type, over the past five years.