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Annex: Notes on Statistics Used in this Bulletin

Data sources

1. The information presented in this bulletin is based on data held in the Scottish Offenders Index ( SOI). This database, which is in turn derived from information held on the police operational computer at the Scottish Criminal Record Office ( SCRO), currently contains a record for each set of criminal proceedings against individuals (excluding companies) in Scottish courts. The data currently covers all convictions where sentence was imposed in the period beginning 1989 and the main offence involved was a crime in Groups 1-5 of the Scottish Government's classification of crimes and offences or the offences of simple assault, breach of the peace, racially aggravated harassment or conduct, miscellaneous firearms offences and social security offences.

2 Each record on the SOI database includes information on the sex and age of the offender, the dates of conviction and sentence, the main offence involved and details of the sentence imposed. Information is also available on any offences which were additional to the main offence involved. Each offender has a unique reference number, which allows individual convictions for that offender to be linked together. (It should be noted that the SOI is a purely statistical database; names and other personal information of offenders are not held).

3. Summary profiles of the offenders and convictions covered in the SOI are given in Tables A1 and A2.

Counting rules and data definitions

4. If more than one set of court proceedings against an offender is disposed of on the same day, then each occasion will be counted as a separate conviction record in the SOI.

5. Generally only the initial court sentence is included in the statistics on convictions, so that, for example, a person fined is regarded as fined even if he or she subsequently goes to prison in default of payment. Similarly, the offenders released from prison who are included in the analysis in this bulletin will only include those directly sentenced to prison, i.e. persons released after imprisonment for fine default are excluded. Also, no account is taken of the outcome of appeals, or of interim decisions such as deferral of sentence.

6. Where a person is convicted for more than one charge, then it is the main offence which is recorded in the SOI. The main offence is taken to be the charge receiving the severest penalty. If more than one charge receives the same (or a combined) penalty, then the main offence is the one judged by the police (who provide the information) to be the most serious. In the analysis of reconvictions presented in this bulletin, where an offender was sentenced for a court or bail-related offence and other offences on the same day, then the most serious of the latter is taken as being the main offence (even where the court or bail offence had attracted the heaviest penalty).

7. Additional information is also available (in analysis data sets separate to the SOI) of court disposals in relation to individual offences. These analysis data sets were created only relatively recently, and as the information on the source SCRO database is constantly updated, they differ marginally from the coverage of the SOI, e.g. to reflect the outcome of appeals. However, these differences are not judged to be significant for the purposes of the statistical analysis presented in this bulletin.

8. The police record very detailed information on statutory offences but this does not always correspond exactly to the Scottish Government classification of crimes and offences. The most important example in numerical terms is an offence under Section 41(1)(a) of the Police (Scotland) Act 1967. This offence relates to "any person who assaults, resists, obstructs, molests or hinders a constable..". Scottish Government classification divides this into 3 categories - resisting arrest, serious assault and simple assault, but this distinction is not made by the courts. The majority of such cases are thought to have been classed as simple assault, and all the offences under this subsection have been so classified from 1988 onwards. Only a minimal number of cases are affected by other instances of this type of problem.

9. The Criminal Justice (Scotland) Act 1995 led to a change in the way in which offending while on bail is treated in the statistics on convictions. Offenders convicted of offending while subject to a bail order issued prior to 1 April 1996 will, if the main result related to the bail re-offending offence, have this classified as the main offence in the conviction record in the SOI. Where the bail order was issued after 1 April 1996, the main offence will be the offence committed while on bail as the aggravation applies to that offence and is not now separately categorised. The effect of the 1995 legislation was therefore to decrease the number of persons with a main offence classified as "bail re-offending" category, with consequent rises in the figures for other categories.

10. In order to analyse reconvictions, a decision has to be made as to which of an individual's convictions in a series is to be taken as a reference point, or index conviction. That is, the conviction before which all convictions are counted as previous convictions, and after which are counted as reconvictions. In this bulletin, the rule for choosing the index conviction is the first occasion in the year in question on which an individual was given a non-custodial sentence, or the first date at which an individual was estimated to have been released from prison from a custodial sentence, whichever occurred first. This is defined to be the offender's index conviction. The crime and sentence involved in this index conviction are referred to throughout this bulletin as the index crime and index disposal respectively. The analysis then considers the proportion of these individuals who are reconvicted within 1 and 2 years from the date of sentence or the estimated prison release date, i.e. from the relevant date of the index conviction. Convictions for a court or bail related offence, are not considered as index convictions. If the first conviction in the year for a particular offender was for such an offence, their next non-court related conviction was taken instead. Where an individual had no further convictions in the year for non-court related crimes they are not included in the data set.

11. Where there is a choice of more than one index conviction for an individual, i.e. where they received more than one sentence disposal on the same day, then the one selected is by reference to a) the most severe form of sentence, and then b) the most serious main offence.

12. Crimes and offences and sentence type have been grouped in this bulletin as follows.

13. The age of each person relates to their age at the time that sentence was passed. This also applies to offenders discharged from a custodial sentence, i.e. their age at the date of sentence rather than estimated release date is taken.

14. Information on actual dates of release for prisoners is not currently available for matching with the conviction data held on the Scottish Offenders Index. For the purposes of the analysis in this bulletin, the date of release for offenders given a custodial sentence has therefore been estimated from their date of sentence, the length of sentence imposed, assumptions about time spent on remand and release on parole, and information about whether the offender had been granted bail. The release date estimated by this approach will inevitably not always tie in with the (unknown) actual release date because the offender may be serving other custodial sentences for example, or because the sentence may have been backdated. However, this is not judged to be significant for the analysis purposes here. The main exception to this relates to offenders discharged from life sentences or, for some cohorts, very long determinate custodial sentences - see note 18 below.

Limitations of reconviction analysis

15. While virtually all convictions since 1989 for all crimes, simple assault, breach of the peace, racially aggravated harassment and conduct, miscellaneous firearm offences and social security offences are covered by the SOI, other types of conviction are not. These include:

• convictions for motor vehicle and most minor statutory and common law offences
• convictions in courts outwith Scotland
• convictions prior to 1989
• any relevant convictions not recorded on SCRO by the end of July 2007

16. All but the most serious of offences alleged to have been committed by children under the age of 16 are generally dealt with by the children's hearings system. The SOI does not currently hold information on offenders' juvenile offending history.

17. Since the SOI does not hold information on the actual dates offences were committed, some reconvictions will be for crimes or offences committed prior to the date of the index conviction. These "pseudo reconvictions" will therefore inflate the apparent reconviction rate, particularly in cases where an offender pleads not guilty.

18. It is not possible using the method described at note 14 above to identify from the data those offenders released in 2003-04 from serving life sentences or, in some instances, very lengthy determinate sentences. This category of offender will therefore not have been available for possible selection for the set of index convictions in each cohort year. However, the number of offenders involved is relatively small (only around 50 offenders receive such sentences each year) and so will not affect the analysis presented in this bulletin significantly. Separate research evidence ( Life Sentence Prisoners in Scotland, Scottish Office, Machin et al, 1999) shows that just over a quarter of the 491 life sentence prisoners released on licence were reconvicted.

Notation

19. The following symbols are used throughout the tables in this bulletin:

- Nil

* Less than 0.5

n/a Not available

Table A1: Profile of offenders on Scottish Offenders Index with at least one conviction since 1989

1. Includes a small number of offenders where sex was not known.
2. Includes probation, restriction of liberty orders and drug treatment and testing orders.
3. Does not include prostitution.

Table A2: Offenders on Scottish Offenders Index with at least one conviction since 1989
Number of convictions since 1989

1. Includes a small number of offenders where sex was not known.

SCOTTISH GOVERNMENT STATISTICIAN GROUP

OUR AIM

To provide relevant and reliable information, analysis and advice that meet the needs of government, business and the people of Scotland.

OBJECTIVES

1. To produce statistics and analysis relevant to user needs by

• Developing our understanding of customer requirements to ensure statistics are kept relevant and analysis is well targeted;
• Developing the range of statistics and analysis we produce;
• Where practicable improving timeliness;
• Providing more statistics disaggregated by age, gender and ethnicity;
• Developing more data for small areas through the Neighbourhood Statistics project;
• Contributing to production of comparable statistics across the UK and internationally.

2. To ensure effective use of our statistics by

• Contributing more directly to policy processes inside and where possible outside government;
• Improving access to and presentation of data and analysis;
• Improving the advice provided on statistics.

3. To work effectively with users and providers by

• Maintaining arrangements to consult and involve users and providers;
• Involving users and providers in planning developments in outputs and processes;
• Minimising the burden on data providers through dropping or streamlining collections as appropriate, to ensure the benefits of the information justify the costs of collection.

4. To develop the quality of statistics by

• Assuring and improving quality as an integral part of data collection and analysis and through regular reviews in line with National Statistics quality strategy;
• Developing statistical methods, systems and classifications;
• Working with the rest of the Government Statistical Service to develop joint approaches/solutions where appropriate.

5. To assure the integrity of statistics by

• Maintaining and promoting integrity through implementation of the National Statistics Code of Practice and related protocols;
• Safeguarding the confidentiality of data subjects.

6. To ensure the efficient and effective delivery of statistics products and services by

• Making best use of all sources including administrative sources;
• Working with other analysts to maximise the contribution of our own and other analysts' work;
• Ensuring value for money;
• Making best use of Information and Communications Technology;
• Ensuring effective communication within the Statistician Group.

7. To develop our workforce and competences

• Ensuring recruitment of staff with the necessary skills and potential;
• Ensuring development of expertise amongst existing staff;
• Promoting and upholding the standards of the statistics profession.

This is a National Statistics publication

"This is a National Statistics publication. It has been produced to high professional standards set out in the National Statistics Code of Practice Protocol - see www.statistics.gov.uk/about_ns/cop/default.asp

These statistics undergo regular quality assurance reviews to ensure that they meet customer needs. They are produced free from any political interference."

Details of pre-release access will be provided in the Scottish Government Statistics Website under 'Forthcoming Releases'

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