3 Index Offences and Sentences
Individuals can be remanded in to custody or sentenced to a custodial disposal for a range of different offences, so the offence profile of the prison population varies. The length of a custodial sentence can also vary considerably, from short determinate sentences to a life sentence. The offence and sentence profiles of those held in custody have implications for population trends, as well as for how individuals are managed within the prison estate.
To allow comparison over time and with other statistical sources on the justice system, we examine the offence profile of those held in custody by index offence only . An index offence is defined within a continuous occupancy period as the offence with the longest sentence. Where there are multiple offences with the same sentence, or for alleged offences with no sentence yet, we use the Criminal Proceedings in Scotland statistics to identify average sentence length by offence type and rank offences accordingly. For more information see section 5.5.
The 35 offence categories (and 7 over-arching offence groups) provide appropriate detail on the nature of offences committed for high-level summary of the prison population and its changes over time, but these categories and groups do mask considerable variation in offending behaviour. By relying on index offence only and using these broad offence categories, the statistics in this section cannot examine the full complexity of the offence profiles of individuals in the prison population. Nevertheless, we do explore broad differences and similarities within key population subgroups (women and young people).
Notable in the following section are increases over time in the average daily population serving sentences for the most serious crime categories. In some categories, for example those falling under ‘Sexual offences’, this reflects an increasing number of criminal proceedings and convictions over the time period examined. In other categories, such as those falling under ‘Non-sexual crimes of violence’, there has been an overall decrease in the number of proceedings for these offence types. Such offences usually receive longer custodial sentences, so the increasing average daily population likely reflects the greater amount of time individuals must serve before departing custody. It also likely reflects changes to release mechanisms over time, and other factors that impact the flows into and out of custody. See section 4.3 for more information on changes to sentenced departures, and section 6 for the broader context of prison population change over time.
3.1 Index Offences in the Sentenced Population
There have been a number of changes in the average daily sentenced population when analysed by index offence between 2009-10 and 2019-20 (Figure 12).
Figure 12 demonstrates that:
- The most common index offence group from 2009-10 to 2019-20 are Violent offences. This category accounts for just over one third of the average daily sentenced population in any given year, peaking at 39% in 2012-13.
- Following a period of sustained reduction from 2012-13 to 2017-18, there was an sharp increase in 2019-20 in the average daily population for whom violence was the index offence.
- There has been a pronounced and continuous increase in the average daily sentenced population held for Sexual index offences since 2012-13, doubling from 8% of the sentenced population in 2009-10 to 16% in 2019-20
- The average daily population for crimes of Dishonesty has been gradually decreasing since 2012-13 (including acquisitive crime)
- Other crimes have accounted for a large proportion of the average daily population over the time period observed, but there has been a considerable decrease in this group between 2009-10 and 2017-18. Despite this overall trend, an increase in the average daily population sentenced for Other crimes was observed in 2018-19 and 2019-20.
- Miscellaneous offences account for a further large proportion of the average daily prison population in any given year, but this group has been broadly stable since 2014-15.
- Fire-raising, vandalism etc., motor vehicle offences and convictions from other jurisdictions comprise only a very small proportion of the average daily prison population in any given year. While these groups show broad stability over time, there has been a small and gradual increase in the average daily population of those whose index offence is ‘Other jurisdiction’.
These trends can be explored in more detail by examining the offence categories within the broad offence groups accounting for the largest proportion of the average daily prison population.
3.1.1 Group 1: Non-sexual crimes of violence
This group contained the first, second and sixth most populous index offence categories in the sentenced population in 2019-20. As Figure 13 shows, regardless of the wider trends over time, the average daily populations for all of these offence categories increased in 2019-20.
‘Attempted murder and serious assault’ is consistently the most common index offence category in this offence group and in the wider sentenced population. After five years at a reduced level, in 2019-20 there was a 10% increase in the average daily sentenced population. This index offence category accounted for 16.7% of the sentenced population in 2019-20.
The average daily population of individuals sentenced for ‘Homicide etc.’ has increased slowly but substantially over time. In 2016-17, ‘Homicide etc.’ went from being the 3rd to the 2nd largest index offence group in the sentenced population, exceeding those held on index drug offences (see section 3.1.4). In 2019-20, there were 720 prisoners serving sentences for ‘Homicide etc.’ on the average day, compared to 567 in 2009-10.
‘Robbery’ was the 6th most common index offence in 2019-20, at 6.6% of the sentenced population. This is down from 5th in 2015-16. There was a 6% increase in this population from 2018-19 to 2019-20 after several years of falling population.
3.1.2 Group 2: Sexual Offences
The average daily population serving sentences for sexual index offences has seen the largest growth of any category over the last decade.
Figure 14 shows that the increase in the average daily population serving sentences for ‘Rape and attempted rape’ is key in driving this population growth. This particular population has trebled since 2009-10, rising from 213 to 640 in 2019-20 and ‘Rape and attempted rape’ has become the third most common index offence in the sentenced population.
The average daily population of those serving sentences for ‘Sexual assault’ has also substantially increased from 2009-10.
3.1.3 Group 3 Crimes of Dishonesty
Following a period of increase between 2009-10 to 2012-13, the average daily population serving sentences for ‘Housebreaking’ fell considerably in 2013-14. However, the population proceeded to increase once again, exceeding 2012-13 numbers (289) in each of the last four years and reaching 303 by 2019-20.
Across other crimes of dishonesty, however, the sentenced population has largely fallen. The average daily population serving sentences for an index offence of ‘Shoplifting’, for example, fell by 38% between 2009-10 and 2019-20, from 158 to 97.
3.1.4 Group 5: Other Crimes
The Other Crimes group includes the 'Crimes against public justice', 'Handling offensive weapons', 'Drugs' categories and a further, nested 'Other other crimes' category.
Within this group, ‘Drugs’ offences accounts for the largest volume of the prison population by a considerable amount. However, there has been a clear reduction in the population serving sentences for index ‘Drugs’ offences over the past decade. ‘Drugs’ went from the 2nd most common index offence in 2009-10 (993) to 4th in 2019-20 (637) following a 36% reduction in the average population. This group accounts for 9.9% of the sentenced population in 2019-20, down from 16.2% in 2009-10. However, there were small increases in the average daily population with index ‘Drugs’ offences in 2018-19 and 2019-20.
The average daily sentenced populations with index offences of ‘Crimes against public justice’ has been broadly stable by volume after a fall from the 2013-14 peak (163 in 2019-20 compared to 220 in 2013-14). The ‘Handling offensive weapons’ population fell from 2012-13 but increased from 245 in 2017-18 to 303 in 2019-20.
The group serving sentences for index offences in the ‘Other other crimes’ category has grown slightly over the past decade, from an average population of 17 in 2009-10 to 48 in 2019-20. These crimes include those associated with serious and organised crime, conspiracy, and obstruction of emergency workers.
3.1.5 Group 6: Miscellaneous Offences
The Miscellaneous Offences group includes ‘Common assault’, ‘Breach of the peace etc.’, ‘Drunkenness and other disorderly conduct’, ‘Public urination’, and a further nested “Other miscellaneous offences” category. Drunkenness and public urination are not observed as index offences in the average daily prison population over the time period examined.
‘Common assault’ is a high volume index offence within the prison population however. It is the largest offence category in this group, and consistently the 4th or 5th largest in the wider sentenced population since 2009-10. It accounts for 8-9% of the sentenced population over this period (8.6% in 2019-20). Although there are some fluctuations, it appears that the average daily population of those serving sentences for an index common assault offence has been on a general upward trend since 2014-15.
The offence category Breach of the Peace etc. has fluctuated over time, with some considerable increases in the average daily population between 2010-11 and 2014-15. This particular offence category has been subject to changes over time, with its definition expanded to include additional offences at various points. For example, this category contains ‘new’ offences relating to stalking and harassment, and threatening or abusive behaviour. It has also included the repealed Offensive Behaviour at Football and Threatening Communications (Scotland) Act 2012 offences. Overall though, there has been an increase in the average daily population serving sentences for ‘Breach of the Peace etc’, rising from 231 in 2009-10 to 303 in 2019-20.
The Other miscellaneous offences category contains a collection of disparate offences, the consistently most common being miscellaneous firearms offences. Similar to other offence categories, despite a period of stability there has been an increase in the average daily population in 2019-20.
3.1.6 Index Offences by Gender
While women comprise a very small proportion of the overall prison population, their index offence profiles have followed some similar patterns to the index offence profiles of men, with the exception of Sexual offences.
- Violent offences account for the single largest proportion of the average daily prison population from 2010-11 to 2019-20.
- A fall in the average daily population serving sentences for Violent offences from 2013-14 to 2017-17, followed by a notable increase in 2018-19 and 2019-20.
- Broad stability in Dishonesty offences, albeit with fluctuation year on year. This differs somewhat from the clear downward trend in the general prison population.
- Relatively small, stable group size across the Fire-raising etc., Motor Vehicle, and Other jurisdiction offence groupings (very small population numbers across all three).
- A sharp fall in Other Crimes, followed by an observable increase in 2019-20.
- Miscellaneous offences follow a similar pattern to the general population with a rise in the average daily numbers to 2012-13. Average daily population numbers remain stable until 2014-15 but fall substantially thereafter to 2019-20; diverging from the trend in the general population.
The most striking difference for the women’s sentenced population in Figure 18 above is that Sexual offences were at very low levels in 2009-10 and have remained at low levels across the time period observed. This is in stark contrast to the large and rapid changes observed in the general population. Figure 19 further highlights the key differences in the offence profiles in the men’s and women’s average daily sentenced populations in 2019-20.
As shown in Figure 19, Violent offences (40%), Other crimes (21%), Dishonesty (17%), and Miscellaneous offences (16%) are the most common offence groupings in the women’s average daily population. In the men’s average daily population, the most common offence groupings are Violent offences (36%), Other crimes (18%), Sexual offences (17%), and Miscellaneous offences (15%). Dishonesty only accounts for 9% of the men’s average daily sentenced population.
3.1.7 Index offences for young people in custody
Figure 20 shows the changing offence profile of young people in custody (under 21 years) over time. In line with the large reduction in this sub-population overall, there have been some large reductions by offence group as well, albeit this is not the case for Sexual offences whereby the average daily population has increased, from 15 in 2010-11 to 28 in 2019-20. As in the adult populations, over the time period observed, the highest volume index offence group amongst young people in custody is Violent offences.
Figure 21 shows how the average daily sentenced population varies by age in 2019-20. A greater proportion of the young people’s average daily population are serving sentences for Violent offences than those aged 21 and over (45% compared to 34%). However, the proportions serving sentences for Sexual offences, Dishonesty and Other crimes are greater in the 21 and over average daily population.
3.2 Index Sentence
In this section we examine the longest individual sentence being served by prisoners in each occupancy period; the ‘index sentence’.
These categories do not represent overall sentence length, which cannot be calculated from the available data due to a lack of information as to whether multiple custodial sentences are to be served consecutively or concurrently. Where an individual is given multiple sentences to be served consecutively (a common occurrence with multiple short sentences), their overall sentence length may be considerably longer than the longest individual sentence. See section 5.6 for more information.
Short-term sentences are those of less than 4 years. As Figure 22 shows, since 2009-10 there has been a broad reduction in the average daily number of individuals serving short index sentences of 6 months or less. Meanwhile, the average daily number of individuals serving 1-2 year sentences has increased steadily over time but with pronounced increases in 2018-19 to 2019-20. The average daily number of individuals serving sentences between 2 and 4 years was decreasing sharply between 2009-10 and 2015-16. Following a period of stability, this number also rose sharply in 2019-20.
Looking at long-term sentences in Figure 22 there have been increases in average daily population size across the board, following both from longer term trends and more recent, rapid growth. There had been a downward trend followed by a short period of stability in the average daily population serving index sentences of 4-10 years. However, in 2018-19 and 2019-20 there have been sharp and substantial increases in average daily numbers, from 1,147 in 2017-18 to 1,318 in 2019-20.
The average daily numbers of individuals serving sentences of 10+ years had been stable between 2009-10 and 2017-18. In the last two years there has been an observable increase in the average daily numbers, from 214 in 2017-18 to 275 in 2019-20.
The average daily number of individuals serving life sentences has also grown, with observable increases between 2009-10 and 2012-13, and again between 2017-18 and 2019-20. By 2019-20, there were 948 individuals (on average) serving life sentences, up from 839 in 2009-10. The average population serving sentences with an Order of Lifelong restriction (OLR) has also grown steadily over time, from 57 in 2009-10 to 185 in 2019-20. In 2019-20, life and OLR sentences combined accounted for 17.1% of the sentenced population (in 2009-10 this figure was 13.8%).
Recalls to custody show another increase in the average daily sentenced population. The number of recalled individuals in the average daily prison population has risen 36% from 296 in 2009-10 to 403 in 2019-20.
3.2.1 Index Sentence Length by Gender
Looking at sentence length trends by gender is challenging due to the smaller numbers of women held in custody in a given year. The pattern of change over time for women is provided in Figure 23.
There are some identifiable trends in the average daily women’s population. There have been clear reductions in the average daily numbers serving very short sentences of 6 months or less between 2009-10 and 2019-20. There have also been substantial reductions in the average daily numbers serving sentences between 2 and 10 years.
There appears to be broad stability in the average daily numbers serving sentences between 6 and 24 months, but with some fairly substantial rises in 2018-19 and 2019-20. This is a similar pattern for the smaller groups serving sentences of 10+ years and those recalled to custody over time.
There has been a clear increase in the average number of women serving life sentences, from 29 in 2009-10 to 49 in 2019-20.
Comparing the women’s average daily population with that of men, there are differences in sentence length profile. As shown in Figure 24, in 2019-20 women were somewhat more likely to have an index sentence of 1 year or less, and around half as likely to have an index sentence of 4 years or more (12% of women compared with 24% of men).
In 2019-20, 16% of women prisoners were serving a life sentence, with none on an Order of Lifelong Restriction. 14% of men were serving life sentences, and 3% on an OLR (Figure 24). Women were around half as likely to have returned to custody on recall.
3.2.2 Index Sentences for Young People in Custody
The overall trend for young people in custody is a dramatic reduction across the all index sentence bands. With the now small populations each year – an average population of 224 in 2019-20 – it is difficult to discern small variations from population trends within index sentence bands, as Figure 25 illustrates.
As shown in Figure 26, in 2019-20, the index sentences for young people in custody were less likely to be long term (4 years or more), or to be life sentences or OLRs when compared against the adult population. Nonetheless, 4.6% of young people in custody were serving life sentences.
3.3 Remand Population Index Offences
As discussed in Section 1 of this report, the remand population comprises individuals who are untried and those who are convicted awaiting sentence. To analyse index offences, these groups are examined together.
Figure 27 shows the changes in levels over time for those held untried or convicted awaiting sentence (taken together termed “Remand”) by alleged offence. The distribution across offence groups differs somewhat from the sentenced population, with a greater proportion of those remanded accused of offences in the “Other Crimes” and “Miscellaneous offences” groups.
In the “Other crimes” group, the volume of alleged offenders falling to 2017-18 and subsequently rising again to 2019-20 is driven by changes in the “Drugs” and “Handling of offensive weapons” index offence category populations.
For the “Miscellaneous Offences” group, the slow-rising trend from 2009-10 to 2019-20 with a peak in 2014-14 through 2016-17 is driven by a combination of alleged “Common assault” and “Breach of the Peace” offences. See section 3.1.5 for more information on these offences.