Scottish Prison Population and Trends 

The accredited official statistics on Scotland’s prison population and the accompanying interactive analysis tool show that the level and composition of the Scottish prison population has changed over time. Prior to the COVID-19 pandemic, Scotland’s prison population had been rising. While the average daily prison population declined between 2012-13 and 2017-18, by late 2018 it was rising rapidly. The average daily prison population peaked at approximately 8,200 in 2019-20. When looking at the number of individuals who were imprisoned during this period, a similar trend can be seen with the number falling by around 13% from 19,923 in 2012-13 to 17,312 in 2019-20. 

The COVID-19 pandemic had considerable impacts on the prison population. The average daily population decreased substantially and stabilised at a lower level from 2020-21 to 2022-23 (between around 7,300 and 7,500 in each of the financial years). In 2023-24 the average daily prison population rose substantially to 7,860.

While there has been a longer term downward trend in the numbers of individuals experiencing imprisonment year-on-year, the number of individuals that spent any time in prison from 2020-21 to 2022-23 was considerably below pre-pandemic levels at 14,243, 14,414 and 14,531 respectively. The number of individuals rose to around 15,349 in 2023-24 (+6% from 2022-23), albeit remaining  lower than pre-pandemic levels.

The difference between the number of individuals that experience imprisonment compared to the average daily prison population in any one year, demonstrates that there is considerable churn in the prison population. Whilst some individuals are serving long sentences, many enter and leave custody after a short period of time. Some individuals enter and leave custody multiple times in any given period. 

The composition of the prison population has also changed over the current reporting period. The sentenced prison population is increasingly comprised of individuals convicted of violent and sexual offences, and serving longer sentences. In 2023-24, those with index offences of non-sexual crimes of violence and sexual crimes comprised just under 70% of the average daily sentenced population. This compares with around 52% in 2012-13. Similarly, the proportion of the average daily sentenced prison population serving index determinate sentences of more than 4 years was around 34% in 2023-24. This compares with 21% in 2012-13.

The age profile of the prison population has also changed. The long term reduction in individuals spending time in custody each year has been driven almost entirely by a reduction in young people and younger adults (those under 30 years), with the average daily population of those aged under 21 years falling considerably from around 681 in 2012-13 to around 168 in 2032-24. At the same time, the average daily population aged 35+ years has increased steadily.

In line with these patterns, the average age of individuals experiencing imprisonment has increased from 32.7 years in 2012-13 to 37.8 years in 2023-24. The proportion of individuals aged 50+ years  has almost doubled over the same period, rising from 7.7% in 2012-13 to 15% in 2023-24.

The prison population is overwhelmingly comprised of men, a consistent pattern over time. Between 2012-13 and 2019-20, women comprised between 4.9% and 5.7% of the annual average daily prison population. The impacts of the COVID-19 pandemic described above were proportionately greater in the women’s prison population. As such, in 2021-22 and 2022-23 the proportion of women in the prison population was just 3.8%. In 2023-24 the proportion of women in the prison population was 4.1%.

A further consistency over time is that arrivals to prison custody are disproportionately drawn from areas of multiple deprivation. The Scottish Index of Multiple Deprivation (SIMD) is the Scottish Government's standard approach to identifying areas of multiple deprivation in Scotland. It is a relative measure of deprivation across 6,976 small areas (data zones). The SIMD ranks areas in Scotland in terms of their relative deprivation. Deprivation is considered in relation to seven domains: income, employment, education, health, access to services, crime and housing. The most deprived 20% of areas are found in quintile 1 or deciles 1 and 2. The least deprived 20% of areas are found in quintile 5 or deciles 9 and 10. Living in an area of deprivation is linked to poorer health outcomes, higher drug use and increased mortality rates.

In 2012-13, around 56% of arrivals to custody were from areas in quintile 1 (deciles 1 and 2), the most deprived 20% of areas in Scotland. In 2023-24, this figure was around 48%.

It should be noted however that SIMD is an area-based measure of relative deprivation therefore not every person from areas ranked as ‘most deprived’ by the SIMD will themselves be experiencing high levels of deprivation or the outcomes associated with living in those areas. Nevertheless, a recent (2022) assessment of Scotland’s prison population found high levels of health and social care needs and of co-morbidity (i.e. individuals having more than one mental health, physical, social care or substance use related need). The final assessment synthesis report also identified a series of challenges to addressing the needs of the prison population through existing health and social care arrangements.