Reconviction rates - offender cohort: 2017 to 2018

Background

This publication presents information on reconvictions and repeat non-court disposals for cohorts of offenders from 1997-98 up to the latest cohort of 2017-18. Cohorts include offenders with an ‘index conviction’ or ‘index non-court disposal’ in the particular financial year. Section one of this publication presents reconviction statistics for offenders with court convictions, section two covers repeat instances of individuals dealt with outside of court (non-court disposals), section three presents analyses of reconviction rates by local authority, and section four looks at the number of previous court convictions for offenders convicted in 2018-19.

Recidivism and reconvictions

Recidivism is where someone has committed an offence and received some form of criminal justice sanction and goes on to commit another offence. Measuring recidivism is important, as it is one indicator of the effectiveness of the criminal justice system in the rehabilitation of offenders. Reconviction rates are a proxy measure for recidivism, as not all offences committed or recorded by the police will necessarily result in a conviction (see Annex A1).

The Scottish justice system

Scotland’s criminal justice system uses a variety of interventions at each stage of the offender’s journey. This system is summarised in the Audit Scotland report (An Overview of Scotland’s Criminal Justice System) and is shown in Chart 2. Not all offences reported to the police result in a conviction, and reoffending is not the same as reconviction, as the intervention of the criminal justice system takes place between these two events. Reconvictions can be affected by many different factors that are not necessarily related to the incidence of crime.

(Source: Audit Scotland 2011 An overview of Scotland’s criminal justice system)

Index convictions: the reference convictions

For the majority of the analyses in this bulletin, we measure reconvictions given by a court for a cohort of offenders within a follow-up period of one year after a conviction given by a court. A cohort is defined as all the offenders that are either estimated to have been released from a custodial sentence (see Annex A7), or given a non-custodial sentence, in a specified financial year. For example, the 2017-18 cohort is the group of offenders who were released from a custodial sentence, or were given a non-custodial sentence, between the 1^st April 2017 and the 31^st March 2018 (See Annex Table A1 and Annex A5). In this bulletin, for brevity, the cohort may be referred to by its year alone, for example 2017-18.

The “index conviction” is the reference conviction given by a court which is determined by either:

(a) the estimated release date for a custodial sentence imposed for the conviction, or

(b) the sentence date for non-custodial sentences imposed for the conviction.

Whichever conviction had the earliest of these dates in a given financial year is defined as the index conviction for an individual offender.

The crime which resulted in the index conviction is the “index crime”, and the sentence given for the index conviction is the “index disposal”. (See Annex Table A1 and Annex A5 for definitions and more details).

Measures of reconviction: the reconviction rate

The reconviction rate is presented as the percentage of offenders in the cohort who were reconvicted one or more times by a court within a specified follow up period from the date of the index conviction. For most reconviction analyses in this bulletin, the follow-up period is one year, except for Table 14 where a two year follow up period is presented. For example, the 2017-18 reconviction rate is 26.3% (Table 1), and this means that just over a quarter of offenders were reconvicted at least once in the year following a non-custodial conviction or release from a custodial sentence in 2017-18. The definitions in Annex Table A1 provide more details about the terminology used in this publication.

Measures of reconviction: average number of reconvictions per offender

The reconviction rate provides an indication of progress in tackling overall offender recidivism. This measure, however, may not be sensitive enough to detect individual-level progress as a result of interventions and programmes in the criminal justice system. Such programmes may have been successful in reducing the number of times offenders are reconvicted, but not completely desisting from committing crimes. This bulletin provides a more detailed analysis of reconvictions by also reporting the complementary measure of the average number of reconvictions per offender.

The average number of reconvictions per offender is a measure of the number of times that offenders in a cohort are reconvicted within the follow-up period. It is calculated as the total number of reconvictions of all the offenders in the cohort, divided by the total number of offenders in the cohort. For example, the average number of reconvictions per offender for the 2017-18 cohort in one year is 0.46 (Table 1). This means that, on average, offenders have just under half a reconviction in a one year follow up period. It should be noted that as this measure is an average, there may be variation in the number of reconvictions that individual offenders have: for example, any group may include offenders with no reconvictions and offenders with multiple reconvictions.

Repeat non-court disposals

This bulletin also presents the repeat non-court disposal rate and the average number of repeat non-court disposals per individual. The repeat non-court disposal rate is analogous to the reconviction rate, and is the proportion of people who receive a non-court disposal and go on to receive another non-court disposal within a year. The average number of repeat non-court disposals per individual, is analogous to the average number of reconvictions, and is a measure of the number of times that a cohort of individuals receive non-court disposals after being given a non-court disposal.

The cohort for non-court disposals is defined as the group of people who receive a non-court disposal, such as a fine or warning, from the police or COPFS in a given financial year. The first non-court disposal in the year is counted as the index non-court disposal, and subsequent non-court disposals given to the individuals within a year are counted as repeat non-court disposals.

Note that court convictions are not included in the repeat non-court disposals, and non-court disposals are not counted towards reconvictions. This is because the court conviction dataset is independent of the non-court disposal dataset. For example, if someone was convicted in court and given a community sentence and were subsequently given a warning by the police, the warning would not be counted as a reconviction. The warning may either be counted as an index non-court disposal if it was the first non-court disposal they received in a financial year, or a repeat non-court disposal if they had already received another non-court disposal in the financial year.

Data Source: The Scottish Offenders Index

Information on reconvictions presented in this bulletin is derived from the Scottish Offenders Index (SOI), which is derived from a subset of the Criminal Proceedings in Scotland dataset. The SOI contains all convictions in court since 1989 where the main offence involved was either a crime in Groups 1-5 of the Scottish Government’s classification of crimes, or some of the offences in Group 6 (see Annex D of the Criminal Proceedings Bulletin for further information about these classification groups). Minor offences, such as drunkenness and the majority of vehicle offences, are excluded from the SOI. This data source is also used to calculate the number and type of previous convictions in section four, which looks back in time at conviction history before the index conviction, as opposed to reconvictions which look at convictions after the index conviction.

A separate dataset in the SOI also contains information on non-court disposals given by the police and COPFS since 2008. This contains non-court disposals given for all crimes and offences, including motor vehicle offences.

The court convictions and non-court disposals are held in separate datasets by the Scottish Government and so are independent of each other and analysed separately in this bulletin.

See Annex B1, Annex B3, and Annex Table A2 for more details.