Safety in custody quarterly bulletin: September 2017
Source: data.gov.uk (2018-05-25)

Safety in Custody. Data on assaults, self-harm and assaults in prisons in England and Wales. Headline figures produced quarterly with more detailed figures produced annually in April.

- 1 - 
 
 
 
Published 25 January 2018 
Safety in Custody Statistics, England and Wales:  
Deaths in Prison Custody to December 2017 
Assaults and Self-harm to September 2017 
Main Points 
Number of deaths 
continues to fall 
 
 
There were 295 deaths in prison custody in the 12 months to 
December 2017, down 17% from 354 in the previous year. Three 
of these were homicides, the same as the previous year. There 
were 70 self-inflicted deaths, down from 122 in the previous year, 2 
of which were in the female estate, compared to 12 in the previous 
12 months.  
Self-harm incidents 
continue to rise, 
reaching record 
highs 
 
 
 
Self-harm reached a record high of 42,837 incidents in the 12 
months to September 2017, up 12% from the previous year. The 
number of incidents requiring hospital attendance rose by 15% to 
3,007. Quarterly self-harm incidents rose by 10% to a record high 
of 11,904 incidents.  
Assaults and 
serious assaults 
continue to rise, 
reaching record 
highs 
 
 
Assaults have continued to increase, reaching a record high of 
28,165 incidents in the 12 months to September 2017, up 12% 
from the previous year. Of these, 3,726 (13%) were serious 
assaults, up 10% from the previous year. In the most recent 
quarter, assault incidents increased by 10% to a new record high of 
7,810. 
Prisoner-on-
prisoner assaults 
continue to rise, 
reaching record 
highs 
 
 
There were 20,346 prisoner-on-prisoner assaults, up 9% from the 
previous year, and the highest in the time series. Of these, 2,961 
(15%) were serious assaults, up 11% from the previous year. 
Prisoner-on-prisoner assaults saw a 10% increase in the latest 
quarter, reaching a new quarterly record high of 5,645. 
Assaults on staff 
continue to rise, 
reaching record 
highs 
 
 
There were 7,828 assaults on staff, up 22% from the previous 
year. Serious assaults on staff reached 787 in the 12 months to 
September 2017, up 3% on the previous period. Assaults on staff 
in the latest quarter increased by 11%, reaching a new quarterly 
record high of 2,225 incidents. 
 
Safety in custody statistics cover deaths, self-harm and assaults in prison custody in England and 
Wales, with figures in quarterly summary tables presented on a 12-month rolling basis over an 
11-year time series. Supplementary annual tables, providing more in-depth statistics on deaths, 
self-harm and assaults on a calendar year basis, underlying data files with pivot tables providing 
lower level granularity, and a guidance technical document are also available alongside this 
bulletin, and can be found at www.gov.uk/government/collections/safety-in-custody-statistics 

 
 
- 2 - 
1 Deaths: 12 months ending December 2017 
Number of deaths continues to fall 
 
In the 12 months to December 2017, there were 295 deaths in prison custody, down 59 from the 
previous year. Of these, 70 deaths were self-inflicted, down 52 from the previous year. 
 
Figure 1: Quarterly 12-month rolling rate of deaths per 1,000 prisoners, 12 months ending 
December 2007 to 12 months ending December 2017, with annualised quarterly rates1  
 
In the 12 months to December 2017 there were 295 deaths in prison custody, a decrease of 17% 
from 354 in the previous year, at a rate of 3.4 deaths per 1,000 prisoners. The most recent 
quarter saw the number of deaths increase to 82, up 19 from the three months to September 
2017. Quarterly death figures should be considered with caution due to greater volatility and the 
potential for seasonal effects. Long-term trends and more detail are presented in annual tables. 
There were 70 apparent self-inflicted deaths, down 43% from 122 in the previous year. On a rate 
basis this is 0.8 instances per 1,000 prisoners. Within the female estate, there were 2 self-
inflicted deaths at a rate of 0.5 per 1,000 prisoners, down from 12 incidents in the previous 12 
months. There were 3 apparent homicides, the same as the previous year. Homicides in prison 
custody remain relatively rare, accounting for around 1% of all deaths over the last ten years. 
There were 184 deaths due to natural causes, a decrease of 10% from 204 in the previous year. 
Natural-cause deaths were at a rate of 2.1 per 1,000 prisoners. 
There were 38 deaths recorded as ‘other’ in the 12 months to December 2017, 34 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), while other cases remain awaiting results at 
the time of publication. There has been a particularly high number of deaths awaiting further 
classification in this period. As a result, the number 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. 
 
                                                 
1 The annualised quarterly rate is an estimate of the annual rate calculated from data in one quarter and 
also taking into account the number of days in that quarter. 
 

 
 
- 3 - 
2 Self-harm: 12 months to September 2017  
Self-harm incidents continue to rise, reaching record highs 
 
Self-harm has reached a record high of 42,837 incidents, up 12% from the previous year. The 
number of incidents also increased by 10% quarter on quarter, to a record high of 11,904. Incidents 
requiring hospital attendance rose by 15% to a record high of 3,007. 
 
Figure 2: Quarterly 12-month rolling rate of self-harm incidents per 1,000 prisoners, 12 
months ending September 2007 to 12 months ending September 2017, with annualised 
quarterly rates 
 
  
In the 12 months to September 2017, there were 42,837 reported incidents of self-harm (a rate of 
501 per 1,000 prisoners), up 12% on the previous year. The number of self-harm incidents 
requiring hospital attendance increased by 15% on the previous year to 3,007 while the 
proportion of incidents that required hospital attendance remained broadly similar at 7.0%. The 
number of self-harm incidents and those requiring hospital attendance are both the highest in the 
time series.  
The quarterly rate of incidents continued to increase in the three months to September 2017 to a 
record high of 11,904 incidents (up 10% on the previous quarter), 807 of which required hospital 
attendance, also the highest figure in the time series.  
The number of prisoners who self-harmed in the 12 months to September 2017 was 11,248 (a 
rate of 131 prisoners per 1,000), up 4% from the previous year. Those that self-harmed did so, on 
average, 3.8 times, although a small number of prolific self-harmers have a disproportionate 
impact on this figure. The majority of those who self-harm in prison do so only once a year. 
Additional detail on this can be found in the annual self-harm tables.

 
 
- 4 - 
Figure 3: Quarterly 12-month rolling rate of self-harm incidents per 1,000 prisoners by 
gender of establishment, 12 months ending September 2007 to 12 months ending 
September 2017  
 
 
 
Self-harm trends differ considerably by gender, with a rate of 427 incidents per 1,000 in male 
establishments (with incidents up 13% on the previous year) compared to a rate of 2,031 per 
1,000 in female establishments (an increase of 9% in the number of incidents from the previous 
year). In the 12 months to September 2017, the number of self-harm incidents per self-harming 
male increased from 3.2 in the previous year to 3.4 while self-harm prolificacy among females 
also increased, from 6.3 to 7.0 incidents per self-harming individual. 
 
Self-harm incidents requiring hospital attendance have increased from the previous year in male 
establishments by 14% to 2,824, and in female establishments by 39% to 183 incidents. While 
self-harmers in female establishments were roughly twice as prolific as those in male 
establishments, the proportion of incidents that required hospitalisation was more than three 
times higher in male establishments (8.1% compared to 2.3% in female establishments). 

 
 
- 5 - 
3 Assaults: 12 months to September 2017 
Assaults and serious assaults continue to rise, reaching record highs 
 
Assaults have continued to rise, reaching a record high of 28,165 incidents in the 12 months to 
September 2017, up 12% from the previous year. Of these, 3,726 were serious assaults, up 10% 
from the previous year, to the highest level in the time series. Quarterly assaults also rose by 10% 
to a record high of 7,810 incidents.  
 
Figure 4: Quarterly 12-month rolling rate of total assaults by gender of establishment, 12 
months ending September 2007 to 12 months ending September 2017, with annualised 
quarterly rates  
 
In the 12 months to September 2017, there were 28,165 assault incidents (a rate of 329 incidents 
per 1,000 prisoners), an increase of 12% on the previous year, and the highest level in the time 
series. In the latest quarter, there were 7,810 assaults, up 10% from the three months to June 
2017.  

 
 
- 6 - 
 
Figure 5: Quarterly 12-month rolling rate of prisoner-on-prisoner assaults and assaults on 
staff, 12 months ending September 2007 to 12 months ending September 2017, with 
annualised quarterly rates  
 
 
There were 20,346 prisoner-on-prisoner assaults in the 12 months to September 2017 (a rate of 
238 per 1,000 prisoners), up 9% on the previous year, and a record high. The latest quarter also 
saw a 10% increase in the number of incidents, reaching a record high of 5,645.  
Assaults on staff reached a record high of 7,828 in the 12 months to September 2017 (a rate of 
91 per 1,000 prisoners), and are up 22% on the previous year. In the most recent quarter, 
assaults on staff rose by 11%, reaching a record high of 2,225 incidents.  
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
- 7 - 
3.1 
Serious assaults 
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 September 2007 to 12 
months ending September 2017, with annualised quarterly rates  
 
 
In the 12 months to September 2017, there were 3,726 serious assaults, up 10% on the previous 
year, and the highest level in the time series. Of these, 2,961 (or 79%) were serious prisoner-on-
prisoner assaults, up 11% on the previous year and also a record high. Over the same period, 
there were 787 serious assaults on staff, up 3% on the previous year.  
In the latest quarter, there were 999 serious assaults, up 4% on the three months to June 2017, 
and a new record high. Of these, 799 (or 80%) were serious prisoner-on-prisoner assaults (up 
4% to a new record high), and 211 were serious assaults on staff (up 3%).  
After a prolonged period of stability in the time series, there has been a clear upward trend since 
December 2012 in serious assault incidents of all types. The number of serious prisoner-on-
prisoner assaults is 2.8 times higher than in the 12 months to September 2012, while serious 
assaults on staff have more than trebled. 

 
 
- 8 - 
Further Information  
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. 
 
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. 
 
Contact 
Press enquiries should be directed to the Ministry of Justice press office:  
Tel: xx-xxxx-xxxx  
Email: xxx@xxx.xx  
 
Other enquiries about these statistics should be directed to:  
Lucy Cuppleditch 
Prison and Probation Analytical Services  
Ministry of Justice 
102 Petty France  
London  
SW1H 9AJ 
Email: xxx@xxx.xx 
 
Next update: 26 April 2018 
URL: www.gov.uk/government/collections/safety-in-custody-statistics  
 
© Crown copyright 
Produced by the Ministry of Justice. 
Alternative formats are available on request from xxx@xxx.xx 
 
 
 
 
 

 
 
- 9 - 
Annex A - Comparison of deaths in custody with the general 
population 
Annex A is updated annually on a calendar year basis when the underlying general population 
data2 become available from the Office of National Statistics, coinciding with the annual 
release of deaths in custody data. 
The prison population is very different from the general population: around 95% of the prison 
population are male, there are no prisoners aged under 15, and relatively few are over 60, 
compared to the general population. As a result, rates of deaths in prison custody cannot be 
compared directly with those for the general population. One technique used for comparing 
mortality rates for different populations is known as the Standardised Mortality Ratio (SMR). 
The SMR provides a means of making like for like comparisons of the death rate in prison 
custody to that of the general population of England and Wales, by adjusting for age distribution 
and gender. Figure A1 below presents the SMR of the prison population, compared to the 
expected level from the general population. Where the likelihood of death is the same as would 
be expected based on the general population, the SMR would have a value of 1 (depicted by the 
green line - a ratio of 1:1). Due to the adjustments, there is a margin of error around the SMR 
estimates, depicted on the graph as the range of values by lines around the point estimates, 
within which there is 95% confidence the true value falls. 
Figure A1: Annual Standardised Mortality Ratio (SMR) for prison population, relative to 
general population (adjusted for age and gender), 2010 to 2017, England and Wales 
0.0
0.5
1.0
1.5
2.0
2010
2011
2012
2013
2014
2015
2016
2017
Standardised Mortality Ratio
 
In 2017, the best estimate of the likelihood of prison mortality was 1.35 times greater than in the 
general population. Across the time series, the likelihood of prison mortality has been significantly 
higher than in the general population, but in 2017 the ratio has returned to similar levels as in 
2013.  
 
                                                 
2 Death figures for the general population, as used in SMR calculations, are derived from the Office of 
National Statistics (ONS) Mortality Statistics at the following link 
www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/deaths/bulletins/deathsregistra
tionsummarytables/2016 and national population figures come from the Population Projections Statistics at 
the following link: 
www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/deaths/bulletins/deathsregistra
tionsummarytables/2016 

 
 
- 10 - 
Figure A2: Annual Standardised Mortality Ratio (SMR) for self-inflicted deaths in the prison 
population relative to suicide in the general population (adjusted for age and gender), 2010 
to 2017, England and Wales 
0
1
2
3
4
5
6
7
8
9
10
11
2010
2011
2012
2013
2014
2015
2016
2017
Standardised Mortality Ratio
  
The Standardised Mortality Ratio in figure A2 above compares the rate of self-inflicted deaths in 
prison custody with the rate of suicide in the general population3, adjusting for age and gender. 
This ratio gives an indication how much greater the likelihood is of this kind of death in prison 
custody, compared to the wider population, on a more comparable basis. HMPPS does not 
attribute intent behind self-inflicted deaths, and as such custody figures may include unintended 
deaths at one’s own hand in addition to suicides. These cannot be isolated from suicides. 
However, the ONS definition of suicide, as used for general population figures, includes 
“injury/poisoning of undetermined intent”. As such, the definitions are closely aligned. 
Across the time series, there has been a considerably higher likelihood of self-inflicted death in 
prison in relation to the likelihood of suicide in the general population. Since 2012 the ratio has 
been widening in the likelihood of self-inflicted death of offenders in custody and the likelihood of 
suicide among the general population. In 2017, with the likelihood of self-inflicted death being 5.1 
times greater, returning to a similar level to the ratio seen in 2013. 
It is important to note that while the SMR accounts for certain risk factors that are 
overrepresented in the prison population (specifically, age and gender), it ignores others, where 
reliable data are not available (e.g. a history of mental health issues or substance abuse). As 
such, it does not provide a definitive answer to the increase in the risk of mortality associated with 
prison custody.  
 
 
 
 
 
 
 
 
 
                                                 
3 
www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/deaths/bulletins/suicidesintheu
nitedkingdom/previousReleases 

 
 
- 11 - 
Annex B – Deaths annual tables key findings 
Gender 
 
The vast majority (over 97%) of deaths in custody occurred in the male estate. The 
number of deaths in the female estate fell by nearly two thirds in 2017 (from 22 to 8 
incidents).  
 
As a result, the cross-tabulations of characteristics with gender (e.g. age by gender, 
ethnicity by gender, etc.) are not presented below because they would be statistically 
meaningless and potentially misleading.  
 
Age 
 
In 2017, prisoners aged 60 and over were the most likely to die in custody, with 27.02 
incidents per 1,000 prisoners. However, of the 130 deaths amongst this age group, all but 
one were classified as natural causes.  
 
Self-inflicted deaths were most frequent among those aged 30 to 39, accounting for 40% 
of all incidents in 2017, but the age group with the highest rate of self-inflicted deaths was 
the 50-59 years bracket, at a rate of 1.17 per 1,000 prisoners. The rate (and number) of 
self-inflicted deaths decreased in all age groups between 2016 and 2017.  
 
Those aged 60 and over accounted for 70% of all natural cause deaths in 2017, with 
those over 50 accounting for 86%.  
 
Time in custody 
 
The first few days of custody are particularly high-risk in terms of self-inflicted deaths. In 
2017, 14% of all self-inflicted deaths occurred within the first week of custody, and 27% 
occurred within the first 30 days.  
 
Moving between prisons poses an additional risk factor. In 2017, 23% of all self-inflicted 
deaths occurred within the first week in the current prison, and 49% occurred within the 
first 30 days.  
 
Offence 
 
In 2017, 44% self-inflicted deaths were by prisoners charged or sentenced to offences of 
violence against the person. Prisoners committing offences of violence against the 
person, robbery and theft account for 67% of self-inflicted deaths. 
 
Ethnicity 
 
In 2017, the rate of self-inflicted deaths was higher amongst White prisoners than BAME 
prisoners at a rate of 0.96 self-inflicted deaths per 1,000 prisoners compared to 0.44 per 
1,000 prisoners for those of BAME ethnicity.  
 
Although the rate of self-inflicted deaths fell from 2016 in both groups, the relative ratio 
remained unchanged, with White prisoners over twice as likely as BAME prisoners to 
suffer a self-inflicted death.  
 
Nationality 
 
In 2017, foreign nationals were more likely than UK nationals, to suffer a self-inflicted 
death, with rates of 1.44 and 0.44 per 1,000 prisoners, respectively. 
 
The rate of self-inflicted deaths was particularly high among EEA nationals, at 2.48 
incidents per 1,000 prisoners.  
 
Status 
 
In 2017, while those who received a determinate sentence accounted for the largest 
proportion of self-inflicted deaths (44%), this was lower than the overall share of 
determinate sentence prisoners in the population (67%). Conversely, prisoners on remand 
or an indeterminate sentence accounted for 29% and 21% of self-inflicted deaths in 2017 
respectively yet their overall share of the population was only 11% and 12% respectively. 
 
 
 

 
 
- 12 - 
Method of self-inflicted death 
 
Hanging remains the most common method of self-inflicted death for both males and 
females in 2017, accounting for over 90% of all incidents. 
 
Of the 66 self-inflicted deaths with method of hanging or self-strangulation in 2017, 
bedding remains the most commonly used ligature type with 79% of incidents using this.  
 
The most commonly used ligature point remains the window, accounting for 45% of all 
self-inflicted hanging or self-strangulation deaths in 2017.