National statistics

Safety in Custody Statistics, England and Wales: Deaths in Prison Custody to June 2023 Assaults and Self-harm to March 2023

Published 27 July 2023

Applies to England and Wales

Number of deaths increased from the previous 12-month period	In the 12 months to June 2023, there were 313 deaths in prison custody, an increase of 9% from 288 deaths in the previous 12 months. Of these, 88 deaths were self-inflicted, a 26% increase from the 70 self-inflicted deaths in the previous 12 months. In the most recent quarter there were 61 deaths, a 32% decrease from 90 deaths in the previous quarter.
The rate of self-harm incidents increased in female establishments but decreased in male establishments from the previous 12-month period	There were 59,722 self-harm incidents in the 12 months to March 2023, up 11% from the previous 12 months, comprising of a 1% decrease in male establishments and a 52% increase in female establishments. Over the same period, the rate of self-harm incidents per 1,000 prisoners, which takes account of the increase in the prison population between this and the previous year, decreased 5% in male establishments but increased 51% in female establishments. In the most recent quarter, there were 16,543 self-harm incidents, up 12% on the previous quarter, comprising a 14% increase in male establishments and a 7% increase in female establishments.
The number of individuals who self-harmed increased	There were 11,224 individuals who self-harmed in the 12 months to March 2023, up 1% from the previous 12 months. The number of self-harm incidents per individual increased from 4.9 in the 12 months to March 2022 to 5.3 in the 12 months to March 2023.
Assaults increased from the previous 12-month period	There were 22,319 assault incidents in the 12 months to March 2023, up 11% from the 12 months to March 2022. In the most recent quarter, assaults were up 11% to 6,000 incidents.
Assaults on staff decreased from the previous 12-month period	There were 7,461 assaults on staff in the 12 months to March 2023, down 2% from the 12 months to March 2022. In the latest quarter the number of assaults on staff increased by 7% to 1,959 incidents.
The number of serious assaults increased 11 % of all assaults were serious	In the 12 months to March 2023, there were 2,564 serious assault incidents, an increase of 23% from the previous 12 months. Serious prisoner-on-prisoner assaults increased by 32% to 1,878, and serious assaults on staff increased 3% to 717 in the 12 months to March 2023.

Statistician’s comment

In the 12 months to June 2023, we have seen an increase in the number of deaths (9% increase). In the 12 months to March 2023, we have seen increases in the number of assault incidents (11% increase) and self-harm incidents (11% increase) compared with the previous year, however both remain lower than pre-pandemic levels. In male establishments, self-harm incidents decreased 1% and assault incidents increased 11%. In female establishments, both self-harm and assault incidents increased, by 52% and 16% respectively, with self-harm incidents reaching their highest level in the time series^{[footnote 1]}. Comparisons of these statistics with earlier periods will reflect the impact of Covid-19 restrictions as well as underlying trends.

The number of deaths has increased to 313 in the 12 months to June 2023. There were 61 deaths in the latest quarter, down from 90 the previous quarter. There were 88 self-inflicted deaths in the latest year, an increase from 70 in the previous year.

There was a 7% increase in the rate of self-harm incidents per 1,000 prisoners in the 12 months to March 2023, comprising a 5% decrease in male establishments and a 51% increase in female establishments. The rate reflected an 11% increase in the number of self-harm incidents in the 12 months to March 2023, and a 4% increase in the average prison population over the same period (as set out in Offender Management Statistics Quarterly^{[footnote 2]}).

There continue to be notable differences in self-harm trends by gender, with the differences increasing substantially in the latest 12 months. The rate in female establishments has increased considerably by 51% to a new peak (5,826 per 1,000 prisoners), whereas it has decreased 5% in male establishments (523 per 1,000 prisoners), meaning the rate is now more than eleven times higher in female establishments. This was driven by a substantial increase in the average number of incidents among those who self-harmed in female establishments, from 11.1 to 17.0, a much larger increase than previously despite this continuing an increasing trend seen for the last six years. By comparison, the average number of incidents among those who self-harmed in male establishments decreased slightly from 4.2 to 4.0.

The rate of assault incidents per 1,000 prisoners increased 7% in the 12 months to March 2023, and the rate of serious assaults increased 19% over the same period. The rate of assaults was 63% higher in female establishments than in male establishments and saw a greater increase in the latest 12 months. In female establishments the rate increased by 16% to a peak of 436 per 1,000 prisoners, compared to an increase of 7% in male establishments (267 per 1,000 prisoners). However, the proportion of assaults in female establishments that were serious remains lower, at 6% compared with 12% in male establishments.

The rate of prisoner-on-prisoner assaults increased 14% in the 12 months to March 2023, and the rate of serious prisoner-on-prisoner assaults increased 28%. The rate of assaults on staff decreased 5% and the rate of serious assaults on staff decreased 1%. This is influenced by the reduced contact included in prison regimes to reduce the risk of Covid-19 infection at different periods since March 2020, and an exit from the National Framework in May 2022.

Background

Safety in custody statistics cover deaths, self-harm and assaults in prison custody in England and Wales, with figures in the summary tables in the quarterly publications presented on a 12-month rolling basis over an 11 year time series^{[footnote 3]}. This release provides statistics on deaths of prisoners to the end of June 2023, and statistics on assaults and self-harm up to the end of March 2023.

The latest 12-month data reflects almost a full year since the exit from the National Framework in May 2022, following the period of Covid-19 restrictions being implemented within prisons to limit and control the spread of the virus. These restrictions included the implementation of effective isolation of prisoners to reduce the spread of Covid-19, reverse cohorting of new entrants to custody, and shielding of vulnerable prisoners. During this period, we have seen progression of establishments to different levels of the National Framework for managing Covid.

The total prison population fell in the period following the first quarter of 2020, more so for certain population groups, but started to increase again in the second quarter of 2021 and as at 30 June 2023 is now higher than pre-Covid levels^{[footnote 4]}. As at 30 June 2023, the total prison population was around 2,900 or 3% higher than at the end of March 2020. The female population has reduced by 7%, whereas the male population has increased by 4%.

These changes in population should be borne in mind when interpreting changes in the numbers of incidents over the past year. In the context of substantial population change, rates per 1,000 prisoners more accurately describe changes in the likelihood of incidents occurring^{[footnote 5]}. Data on deaths, self-harm and assaults are routinely presented as rates of incidents per 1,000 prisoners (as well as numbers) for all prisoners and the male and female estates. Additional commentary is offered where these rates indicate different trends to the numbers of incidents.

Supplementary annual tables, providing more in-depth statistics on a calendar year basis, underlying data files with pivot tables providing lower-level granularity, and a technical guidance document are also available alongside this bulletin, at

https://www.gov.uk/government/collections/safety-in-custody-statistics.

Youth estate and changes in methodology in Safety in Custody

These statistics exclude incidents that occurred in the youth estate that were previously included within this publication. Readers should be aware of the ‘Safety in the children and young people secure estate’ statistics bulletin which is published simultaneously to this Safety in Custody quarterly bulletin. This provides quarterly statistics on assault and self-harm incidents for children and young people in the secure estate, and is published at the following link:

https://www.gov.uk/government/statistics/announcements/safety-in-the-youth-secure-estate-bulletin.

Figures for the number of self-harm and assault incidents occurring within the youth estate were removed from the published Safety in Custody statistics from the July 2022 release, please see that publication for more details. The figures in this publication exclude incidents occurring within the youth estate from April 2018 onwards for assaults, and from April 2019 onwards for self-harm. It has not been possible to identify such incidents occurring in the youth estate before these dates and so create a longer consistent time-series. This is because figures for incidents occurring within the youth estate for assaults up to March 2018 and for self-harm up to March 2019 were collected via manual returns. This has led to a discontinuity in the time series for assaults and self-harm. The Safety in Custody time series includes deaths in the youth estate, with the last recorded death being in 2019.

Deaths: 12 months to June 2023

Number of deaths increased from the previous 12-month period	In the 12 months to June 2023, there were 313 deaths in prison custody, an increase of 9% from 288 deaths in the previous 12 months. In the most recent quarter there were 61 deaths, a 32% decrease from 90 deaths in the previous quarter.
Number of self-inflicted deaths increased from the previous 12-month period	In the 12 months to June 2023, there were 88 self-inflicted deaths, an increase of 26% from 70 in the previous 12 months. There were 17 self-inflicted deaths in the most recent quarter, a 35% decrease from 26 in the previous quarter.

Figure 1: Quarterly 12-month rolling rate of deaths per 1,000 prisoners, 12 months ending June 2013 to 12 months ending June 2023, with quarterly rates

In the 12 months to June 2023, there were 313 deaths in prison custody (a rate of 3.8 per 1,000 prisoners), an increase from 288 deaths in the previous 12 months (a rate of 3.6 per 1,000 prisoners). Long-term trends and more detail are presented in the annual tables^{[footnote 6]}.

Over the same period, there were 185 deaths due to natural causes (a rate of 2.2 per 1,000 prisoners), a 7% decrease from 198 deaths (a rate of 2.5 per 1,000 prisoners) in the previous 12 months.

There were 88 apparent self-inflicted deaths in the 12 months to June 2023 (a rate of 1.1 per 1,000 prisoners), an increase of 26% from 70 self-inflicted deaths in the previous 12 months (a rate of 0.9 per 1,000 prisoners).

There were 37 deaths recorded as ‘Other’ in the 12 months to June 2023, 31 of which are ‘awaiting further information’ prior to being classified. In some cases, the results of the toxicology and post-mortem tests are inconclusive, meaning classification cannot be arrived at until inquest (which can be a considerable time after the death). As a result, the number and rate of deaths in the individual categories is not directly comparable with earlier years: it is likely that numbers in some categories will be revised upwards once classifications have been finalised.

In the most recent quarter there were 61 deaths, a 32% decrease from 90 deaths in the previous quarter. There were 17 self-inflicted deaths in the latest quarter, a 35% decrease from 26 in the previous quarter. However, quarterly death figures should be considered with caution due to greater volatility and the potential for seasonal effects.

Self-harm: 12 months to March 2023

The rate of self-harm incidents decreased in the male estate from the previous 12-month period but increased in the female estate	There were 59,722 self-harm incidents in the 12 months to March 2023, an 11% increase from the previous 12 months (a 1% decrease in male establishments and a considerable 52% increase in female establishments). Over the same period the rate of self-harm incidents per 1,000 prisoners decreased by 5% in male establishments and increased by 51% in female establishments. In the most recent quarter, there were 16,543 self-harm incidents, up 12% on the previous quarter (a 14% increase in male establishments and a 7% increase in female establishments).
The number of individuals who self-harmed increased 1% in the latest year.	There were 11,224 individuals who self-harmed in the 12 months to March 2023, a 1% increase from 11,079 in the previous 12 months. The number of self-harm incidents per individual increased from 4.9 in the 12 months to March 2022 to 5.3 in the 12 months to March 2023.

Statistics for the 12 months to March 2023 relate to the third full 12-month period since the start of the Covid-19 pandemic and the restricted regimes prisons put in place in order to safely manage the risks of infection during the pandemic, including an exit from the National Framework in May 2022, this affects the comparability of the statistics with previous years.

Figure 2: Quarterly 12-month rolling rate of self-harm incidents per 1,000 prisoners, 12 months ending March 2013 to 12 months ending March 2023, with quarterly rates

In the 12 months to March 2023, there were 59,722 reported incidents of self-harm (a rate of 733 per 1,000 prisoners), an increase of 11% from 53,753 in the previous 12 months. The rate of incidents in the latest 12 months increased 7% from the previous 12 months.

On a quarterly basis, the number of incidents in the three months to March 2023 increased by 12% from the previous quarter, from 14,816 to a new peak of 16,543 incidents.

The number of individuals who self-harmed increased by 1% to 11,224 in the latest 12 months (a rate of 138 individuals per 1,000 prisoners), from 11,079 in the previous 12 months. The rate, or proportion, of prisoners self-harming in the latest 12 months was 2% lower than in the previous 12 months. The number of incidents per self-harming individual in the latest 12 months reached a new peak of 5.3, an increase from 4.9 in the previous year. A small number of individuals who prolifically self-harm have a disproportionate impact on this figure: just over a half (51%) of prisoners who self-harmed in 2022 did so more than once.

The number of self-harm incidents requiring hospital attendance increased by 3% to 2,777 in the 12 months to March 2023 and increased by 19% in the latest quarter to 736 incidents. The proportion of incidents that required hospital attendance has been on a downward trend from 7.1% in the 12 months to March 2016 to 4.6% of incidents in the latest 12 months.

Self-harm levels differ considerably by gender. Although the number of incidents in the female estate is smaller than in the male estate, the rate of self-harm per 1,000 prisoners is much higher. In the 12 months to March 2023, there were 40,934 incidents in the male estate compared with 18,788 in the female estate, representing a 1% decrease in male establishments and a 52% increase in female establishments compared to the previous year. However, the rate of self-harm in the female estate (5,826 incidents per 1,000 prisoners) was over eleven times higher than in the male estate (523 incidents per 1,000 prisoners), following a 5% decrease in male establishments and a 51% increase in female establishments. The number of incidents and rate of self-harm in the female estate are now at the highest level in the time series^{[footnote 7]}.

The number of incidents per individual who self-harmed in female establishments was over four times that in male establishments. In the 12 months to March 2023 there were 17.0 incidents of self-harm per self-harming female, a considerable increase from 11.1 in the previous 12 months, compared with 4.0 incidents per self-harming male, which was a slight decrease from 4.2 in the previous 12 months.

The proportion of females self-harming in the latest 12 months was 2% lower than in the previous 12 months, at 342 individuals per 1,000 prisoners; the increase in self-harm in the female estate has been driven by the substantial increase in incidents per self-harming individual. Over the same period, the proportion of prisoners self-harming in male establishments also decreased by 2%, to 129 individuals per 1,000 prisoners.

Figure 3: Quarterly 12-month rolling rate of self-harm incidents per 1,000 prisoners by gender of establishment, 12 months ending March 2013 to 12 months ending March 2023

Self-harm incidents requiring hospital attendance increased in male establishments by 1%, to 2,475 in the 12 months to March 2023, and the proportion of incidents requiring hospital attendance increased from 5.9% in the previous 12 months to 6.0% in the latest 12 months. In the female estate 302 self-harm incidents required hospital attendance, an increase from 235 incidents the previous year. The proportion of incidents in the female estate requiring hospital attendance was 1.6% in the 12 months to March 2023, down from 1.9% in the previous 12 months, reflecting that the considerable increase in self-harm incidents in the female estate has been in incidents not requiring hospital treatment.

On a quarterly basis, the number of incidents in the three months to March 2023 increased by 14% in male establishments and increased 7% in female establishments compared with the previous three months. The number of incidents in female establishments peaked at 5,469 in the latest quarter.

As Figure 3 shows, over the last decade there has been more variation in the quarterly rate of self-harm in the female estate than in the male estate. This may in part reflect the impact of the small number of individuals who engage in prolific self-harming being greater in the female estate. Fluctuations in the quarterly rates of self-harm in the female estate have been wider since the start of the pandemic, with the peak in the most recent quarter.

Assaults: 12 months to March 2023

Assaults and serious assaults increased from the previous 12-month period.	In the 12 months to March 2023, there were 22,319 assault incidents, an 11% increase from the previous 12 months. Of these, 2,564 were serious assaults, up 23%. Rates of assault and serious assault per 1,000 prisoners increased 7% and 19% respectively in the latest 12 months. Assaults increased 11% in the latest quarter to 6,000 incidents while the number of serious assaults increased by 4% to 653 incidents.
The rate of assault per 1,000 prisoners was higher in female than male establishments.	The rate of assault in male establishments increased by 7% from the previous 12 months, while the rate in female establishments increased by 16%. Assault rates for the 12 months to March 2023 remained higher in female establishments (436 incidents per 1,000 prisoners) than in male establishments (267 incidents per 1,000 prisoners).
Assaults on staff decreased from the previous 12-month period.	There were 7,461 assaults on staff in the 12 months to March 2023, a 2% decrease from the previous 12 months. In the latest quarter the number of assaults on staff increased by 7% to 1,959 incidents. The rate of assaults on staff per 1,000 prisoners decreased by 5% in the latest 12 months, comprising decreases of 6% in male establishments and 1% in female establishments compared with the previous 12 months.

Statistics for the 12 months to March 2023 relate to the third full 12-month period since the start of the Covid-19 pandemic and the restricted regimes prisons put in place in order to safely manage the risks of infection during the pandemic, including an exit from the National Framework in May 2022, this affects the comparability of the statistics with previous years.

Figure 4: Quarterly 12-month rolling rate of total assaults by gender of establishment, 12 months ending March 2013 to 12 months ending March 2023, with quarterly rates

In the 12 months to March 2023, assault incidents increased by 11% to 22,319 (a rate of 274 incidents per 1,000 prisoners). The rate of assaults in the latest 12 months was 7% higher than in the previous 12 months.

In the latest quarter there were 6,000 assaults, up 11% from the previous quarter. The number of assaults and the quarterly rate remain lower than their peak in the July to September 2018 quarter. This reflects that quarterly numbers and rates of assaults were already falling before the outbreak of the Covid-19 pandemic as well as the considerable decrease in the early stages of the pandemic (April to June 2020) associated with changes in prison regimes and activity in the criminal justice system.

The number of incidents in male establishments increased by 11% from 18,686 to 20,914 in the 12 months to March 2023 (a rate of 267 per 1,000 prisoners). The rate of assaults in male establishments in the latest 12 months was 7% higher than in the previous 12 months.

The number of incidents in female establishments increased by 16% from 1,208 to 1,405 incidents in the 12 months to March 2023 (a rate of 436 per 1,000 prisoners). The rate of assaults in female establishments in the latest 12 months was 16% higher than in the previous 12 months, and is now at its highest level in the time series^{[footnote 8]}.

Assault rates have been higher in female establishments than in male establishments since the 12 months to March 2019, with the difference extending each year, after previously being higher in male establishments.

In the latest quarter, the number of assaults in male establishments increased 12% from 5,038 to 5,639, and the number of assaults in female establishments remained almost unchanged (a 0.6% increase from 359 to 361).

Figure 5: Quarterly 12-month rolling rate of prisoner-on-prisoner assaults and assaults on staff, 12 months ending March 2013 to 12 months ending March 2023, with quarterly rates

There were 15,100 prisoner-on-prisoner assaults^{[footnote 9]} in the 12 months to March 2023 (a rate of 185 per 1,000 prisoners), an increase of 18% from the 12,773 assaults in the previous 12 months. The rate of prisoner-on-prisoner assaults in the latest 12 months was 14% higher than in the previous 12 months. In the latest quarter, there were 4,109 prisoner-on-prisoner assaults, a 14% increase from 3,620 in the previous quarter.

There were 7,461 assaults on staff^{[footnote 10]} in the 12 months to March 2023 (a rate of 92 per 1,000 prisoners), a decrease of 2% from the 7,598 assaults in the previous 12 months. The rate of assaults on staff in the latest 12 months was 5% lower than in the previous 12 months. In the latest quarter, there were 1,959 assaults on staff, a 7% increase from 1,829 incidents in the previous quarter.

The proportion of assaults on staff^{[footnote 11]} decreased to 33% of all incidents in the 12 months to March 2023, from 38% in the previous 12 months, having previously steadily increased from 21% in the 12 months to March 2013 to a peak of 39% in the year to March 2021.

In male establishments, prisoner-on-prisoner assaults increased by 17% to 14,343 incidents (183 incidents per 1,000 male prisoners) in the 12 months to March 2023, and the rate increased 13%. Assaults on staff decreased 2% to 6,810 incidents (87 incidents per 1,000 male prisoners), with the rate decreasing 6%.

In female establishments, prisoner-on-prisoner assaults increased by 34% to 757 incidents (235 incidents per 1,000 female prisoners) in the 12 months to March 2023, and the rate increased by 33%. Assaults on staff remained almost unchanged at 651 (a decrease of 0.3%), while the rate was also almost unchanged at 202 incidents per 1,000 female prisoners (a decrease of 0.9%), compared to the previous 12 months. Prior to the latest year the rate of assaults on staff had been steadily increasing, from a rate of 43 incidents per 1,000 female prisoners in the 12 months to March 2014.

In the 12 months to March 2023, the proportion of assaults that were on staff remained higher in female establishments (46%) than in male establishments (33%).

Serious assaults

Of the 22,319 assault incidents, 2,564 (11%) were serious	In the 12 months to March 2023, there were 2,564 serious assault incidents, a 23% increase from the previous 12 months. The rate of serious assault increased by 19% over the period. Serious prisoner-on-prisoner assaults increased by 32% to 1,878, and serious assaults on staff increased by 3% to 717 in the 12 months to March 2023.

Serious assaults are those which fall into one or more of the following categories: a sexual assault; requires detention in outside hospital as an in-patient; requires medical treatment for concussion or internal injuries; or incurs any of the following injuries: a fracture, scald or burn, stabbing, crushing, extensive or multiple bruising, black eye, broken nose, lost or broken tooth, cuts requiring suturing, bites, temporary or permanent blindness.

Figure 6: Quarterly 12-month rolling rate of total serious assaults, serious prisoner-on-prisoner assaults, and serious assaults on staff, 12 months ending March 2013 to 12 months ending March 2023

In the latest 12 months, 11% of assaults were serious assaults. The proportion of all assaults that were serious was higher in male establishments (12%) than in female establishments (6%).

In the 12 months to March 2023, there were 2,564 serious assaults (a rate of 31 per 1,000 prisoners), a 23% increase from the previous 12 months. The rate of serious assaults in the latest 12 months was 19% higher than in the previous 12 months. In the latest quarter, there were 653 serious assaults, a 4% increase from the previous quarter.

There were 1,878 serious prisoner-on-prisoner assaults (a rate of 23 per 1,000 prisoners) in the 12 months to March 2023, a 32% increase from the previous 12 months. The rate of serious prisoner-on-prisoner assaults in the latest 12 months was 28% higher than in the previous 12 months. In the latest quarter, there were 484 serious prisoner-on-prisoner assaults, a 3% increase from the previous quarter.

There were 717 serious assaults on staff (a rate of 9 per 1,000 prisoners) in the 12 months to March 2023, a 3% increase from the previous 12 months. The rate of serious assaults on staff in the latest 12 months was 1% lower than in the previous 12 months. In the latest quarter, the number of serious assaults on staff increased by 9% to 173 incidents.

Further information

National Statistics status

National Statistics status means that official statistics meet the highest standards of trustworthiness, quality and public value.

All official statistics should comply with all aspects of the Code of Practice for Official Statistics. They are awarded National Statistics status following an assessment by the UK Statistics Authority’s (UKSA) regulatory arm. The UKSA considers whether the statistics meet the highest standards of Code compliance, including the value they add to public decisions and debate.

It is the Ministry of Justice’s responsibility to maintain compliance with the standards expected for National Statistics. If we become concerned about whether these statistics are still meeting the appropriate standards, we will discuss any concerns with the UKSA promptly. National Statistics status can be removed at any point when the highest standards are not maintained, and reinstated when standards are restored.

Our statisticians regularly review the content of publications. Development of new and improved statistical outputs is usually dependent on reallocating existing resources. As part of our continual review and prioritisation, we welcome user feedback on existing outputs including content, breadth, frequency and methodology. Please send any comments you have on this publication including suggestions for further developments or reductions in content.

Accompanying files

As well as this bulletin, the following products are published as part of this release:

• A technical guide providing further information on how the data are collected and processed, as well as information on the revisions policy and legislation relevant to sentencing trends and background on the functioning of the criminal justice system.

• A set of summary tables for the latest quarter, and annual tables up to the latest calendar year.

• Underlying data files with pivot tables, giving lower level granularity.

Future publications

Our statisticians regularly review the content of publications. Development of new and improved statistical outputs is usually dependent on reallocating existing resources. As part of our continual review and prioritisation, we welcome user feedback on existing outputs including content, breadth, frequency and methodology. Please send any comments you have on this publication including suggestions for further developments or reductions in content.

Contact

Press enquiries should be directed to the Ministry of Justice press office: Tel: 020 3334 3536 Email: newsdesk@justice.gov.uk

Other enquiries about these statistics should be directed to:

Jon Mitchell

Data and Analysis, Ministry of Justice,
102 Petty France,
London,
SW1H 9AJ

Email: OMSQ-SiC-publications@justice.gov.uk

Next update: October 2023 URL: https://www.gov.uk/government/collections/safety-in-custody-statistics

© Crown copyright

Produced by the Ministry of Justice.

Alternative formats are available on request from OMSQ-SiC-publications@justice.gov.uk

1. The time series for assault incidents starts in 2000, and self-harm incidents starts in 2004. ↩

2. Data on population statistics are published in the Offender Management Statistics Quarterly publication https://www.gov.uk/government/collections/offender-management-statistics-quarterly. ↩

3. Data on deaths is published three months ahead of self-harm and assaults. Therefore, the deaths annual publication and tables are published alongside the Safety in Custody quarterly update to September publication. ↩

4. https://www.gov.uk/government/collections/offender-management-statistics-quarterly. Quarterly population data to June 2023 is published in Offender Management Statistics Quarterly Bulletin, England and Wales Quarterly. ↩

5. The comparability over the year of other measures that are based on self-harming individuals (such as the number of incidents per self-harming individual, or the proportion of incidents requiring hospital attendance) are not affected by changes in population size. ↩

6. Data on deaths are published three months ahead of assaults and self-harm, therefore, the annual publication Deaths in prison custody for 1978 to 2022 is published in the Safety in Custody quarterly update to September 2022. ↩

7. The time series for assault incidents starts in 2000, and self-harm incidents starts in 2004. ↩

8. The time series for assault incidents starts in 2000, and self-harm incidents starts in 2004. ↩

9. This figure includes any prisoner-on-prisoner assaults where there may also have been an assault on staff. ↩

10. There was a change in how staff assaults have been recorded from April 2017, this has simplified how incidents involving staff are identified, however it is possible this has increased the recording of incidents. Please see the Guide to Safety in Custody statistics for further information. ↩

11. Some assault incidents may be recorded as both a prisoner-on-prisoner assault and an assault on staff, so the sum of the two categories may exceed the total number of assaults. ↩