As of February 2025, El Salvador had the highest prisoner rate worldwide, with over 1,600 prisoners per 100,000 of the national population. Cuba, Rwanda, Turkmenistan, and the United States, rounded out the top five countries with the highest rate of incarceration. Homicides in El Salvador Interestingly, El Salvador, which long had the highest global homicide rates, has dropped out of the top 20 after a high number of gang members have been incarcerated. A high number of the countries with the highest homicide rate are located in Latin America. Prisoners in the United StatesThe United States is home to the largest number of prisoners worldwide. More than 1.8 million people were incarcerated in the U.S. at the beginning of 2025. In China, the estimated prison population totaled 1.69 million people that year. Other nations had far fewer prisoners. The largest share of the U.S. prisoners in federal correctional facilities were of African-American origin. As of 2020, there were 345,500 black, non-Hispanic prisoners, compared to 327,300 white, non-Hispanic inmates. The U.S. states with the largest number of prisoners in 2022 were Texas, California, and Florida. Over 160,000 prisoners in state facilities were sentenced for rape or sexual assault, which was the most common cause of imprisonment. The second most common was murder, followed by aggravated or simple assault.

At the beginning of 2025, the United States had the highest number of incarcerated individuals worldwide, with around 1.8 million people in prison. China followed with around 100,000 fewer prisoners. Brazil followed in third. The incarceration problem in the U.S. The United States has an incredibly high number of incarcerated individuals. Therefore, the incarceration problem has become a widely contested issue, because it impacts disadvantaged people and minorities the most. Additionally, the prison system has become capitalized by outside corporations that fund prisons, but there is still a high cost to taxpayers. Furthermore, there has been an increase in the amount of private prisons that have been created. For-profit prison companies have come under scrutiny because of their lack of satisfactory staff and widespread lobbying. Violent offenses are the most common type of offense among prisoners in the U.S. Incarceration rates worldwide El Salvador had the highest rate of incarceration worldwide, at 1,659 prisoners per 100,000 residents as of February 2025. Cuba followed in second with 794 prisoners per 100,000 inhabitants. The incarceration rate is a better measure to use when comparing countries than the total prison populations, which will naturally have the most populous countries topping the list.

As of December 2022, there was a total of 139,631 prisoners in the state of Texas, the most out of any state. California, Florida, Georgia, and Ohio rounded out the top five states with the most prisoners in the United States.

Context

In 1975, the United States set a new record with 240,593 prisoners incarcerated by state or federal agencies. The United States achieved new record totals during each of the next 34 years. Today, there are over 1,500,000 prisoners in the United States. Over one quarter of the world's entire population of prisoners is located in the United States.

The U.S. Education deparment reports state and local government expenditures on prisons (and jails - not reflected in this dataset) have increased about three times as fast as spending on elementary and secondary education during this time period. Does this significant investment into imprisonment improve public safety? This dataset brings together crime and incarceration statistics to help researchers explore this relationship.

Content

The Bureau of Justice Statistics administers the National Prisoners Statistics Program (NPS), an annual data collection effort that began in response to a 1926 congressional mandate. The population statistics reflect each state's prisoner population as of December 31 for the recorded year. Prisoners listed under federal jurisdiction are incarcerated by the U.S. Bureau of Prisons.

The Uniform Crime Report (UCR) has served as the FBI's primary national data collection tool since a 1930 congressional mandate directed the Attorney General to "acquire, collect, classify, and preserve identification, criminal identification, crime, and other records." The FBI collects this information voluntarily submitted by local, state, and fedral law enforcement agencies. Some U.S. municipalities choose not to participate fully in the program. The crimes_estimated field indicates cases where the FBI estimated state totals due to lack of participation by some municipalities within a state. The crime_reporting_change field reflects instances when states' reporting standards change. For more information on the responsible use of this dataset, please see Uniform Crime Reporting Statistics: Their Proper Use

Acknowledgements

State and Federal prisoner population figures published by Bureau of Justice Statistics.

State crime and population statistics published by the FBI Uniform Crime Reporting (UCR) Program. https://www.ucrdatatool.gov/Search/Crime/State/RunCrimeStatebyState.cfm

Banner Photo by Oscar Söderlund on Unsplash

Inspiration

What is the relationship between incarceration rates and crime rates? Does mass incarceration improve public safety? See below for some recent statements from U.S. politicians related to the relationship between crime and incarceration. Are the data consistent with any of these statements?

"There is no better way to reduce crime than to identify, target, and incapacitate those hardened criminals... we cannot incapacitate these criminals unless we build sufficient prison and jail space to house them. " - Nominee for 85th U.S. Attorney General William Barr, [October 28, 1992][13]

"Violent crime has declined since the 1980s because mandatory minimums adopted then locked up violent criminals." - Senator Tom Cotton, August 15, 2018

"You may assume mass incarceration exists because people are committing more crimes. But that is not true... The incredibly costly reality is that prisons in our nation continue to grow irrespective of crime rates. It is a bureaucracy that has been expanding independent of our security or safety." - Senator Cory Booker, Apr 28, 2015

"It is far from clear whether this dramatic increase in incarceration for drug crimes has had enough of an effect on property and violent crime rates to justify the human toll of more incarceration." - Senator Ted Cruz, Apr 27, 2015

"For several decades, tough laws and long sentences have created the illusion that public safety is best served when we treat all offenders the same way: arrest, convict, incarcerate..." - Senator Kamala Harris, [Apr 27, 2015][11]

"We've got some space to put some people! We need to reverse a trend that suggested that criminals won't be confronted seriously with their crimes" - 84th U.S. Attorney General Jeff Sessions, [March 15, 2018][12]

...

There were about 87,784 female prisoners under the jurisdiction of state or federal correctional authorities in the United States as of December 2022. This is an increase from the previous year, when there were 83,651 female prisoners in the country.

Private prisons, also referred to as for-profit prisons, have become a dominant sector of society in the United States and are now implemented in many states around the country. As of 2022, the state of Florida had the highest number of prisoners held in private prisons in the United States, with a total of ****** prisoners, followed by Texas, Arizona, and Georgia, and Tennessee. ** states did not have any prisoners held in private prisoners in that year. Private prisons in the U.S. The United States is home to the highest prison population per capita of all OECD countries, resulting in a consistent overcrowding of prisons which has negatively affected the criminal justice system for decades. The privatization of prison facilities was initially proposed as a solution to a lack of funding and an increasing demand for more jail space, leading to around *** percent of the U.S. prison population currently behind bars in private prisons. In 2021, ****** prisoners were held in in-state private prison facilities in the United States, compared to ****** prisoners held in out-of-state private prisons. Arguments on private prisons Advocates of private prisons proposed that privatization could lead to cost reductions, suggesting that allowing the private industry to operate prison facilities would save taxpayers money. However, the increasing reliance on private prison facilities has been criticized politically in the U.S. for catering to profit-seeking corporations as well as for the tendency to hold people in immigrant detention in these privately run facilities. In 2021, the highest share of revenue reported by the two largest for-profit prison companies in the U.S. was from U.S. Immigration and Customs Enforcement. In addition, Republican Senator Marco Rubio from Florida, who is well-known for his positive stance on strengthening border security, was also found to receive the most money from the private prison industry than any other federal politician in the 2022 election cycle.

The prison boundary feature class contains secure detention facilities. These facilities range in jurisdiction from federal (excluding military) to local governments. Polygon geometry is used to describe the extent of where the incarcerated population is located (fence lines or building footprints). This feature class’s attribution describes many physical and social characteristics of detention facilities in the United States and some of its territories.

Original Data

Acknowlegement

Foto von Milad Fakurian auf Unsplash

This study assessed the effects of male inmate religiosity on post-release community adjustment and investigated the circumstances under which these effects were most likely to take place. The researcher carried out this study by adding Federal Bureau of Investigation criminal history information to an existing database (Clear et al.) that studied the relationship between an inmate's religiousness and his adjustment to the correctional setting. Four types of information were used in this study. The first three types were obtained by the original research team and included an inmate values and religiousness instrument, a pre-release questionnaire, and a three-month post-release follow-up phone survey. The fourth type of information, official criminal history reports, was later added to the original dataset by the principal investigator for this study. The prisoner values survey collected information on what the respondent would do if a friend sold drugs from the cell or if inmates of his race attacked others. Respondents were also asked if they thought God was revealed in the scriptures, if they shared their faith with others, and if they took active part in religious services. Information collected from the pre-release questionnaire included whether the respondent attended group therapy, religious groups with whom he would live, types of treatment programs he would participate in after prison, employment plans, how often he would go to church, whether he would be angry more in prison or in the free world, and whether he would be more afraid of being attacked in prison or in the free world. Each inmate also described his criminal history and indicated whether he thought he was able to do things as well as most others, whether he was satisfied with himself on the whole or felt that he was a failure, whether religion was talked about in the home, how often he attended religious services, whether he had friends who were religious while growing up, whether he had friends who were religious while in prison, and how often he participated in religious inmate counseling, religious services, in-prison religious seminars, and community service projects. The three-month post-release follow-up phone survey collected information on whether the respondent was involved with a church group, if the respondent was working for pay, if the respondent and his household received public assistance, if he attended religious services since his release, with whom the respondent was living, and types of treatment programs attended. Official post-release criminal records include information on the offenses the respondent was arrested and incarcerated for, prior arrests and incarcerations, rearrests, outcomes of offenses of rearrests, follow-up period to first rearrest, prison adjustment indicator, self-esteem indicator, time served, and measurements of the respondent's level of religious belief and personal identity. Demographic variables include respondent's faith, race, marital status, education, age at first arrest and incarceration, and age at incarceration for rearrest.

In 2022, 0.2 percent of female prisoners in the United States were aged between 18 and 19 years old. In that year, 16.1 percent of male prisoners in the U.S. were between the ages of 30 and 34 years old.

This survey provides nationally representative data on inmates held in state prisons and federally-owned and operated prisons. Through personal interviews conducted from October 2003 through May 2004, inmates in both state and federal prisons provided information about their current offense and sentence, criminal history, family background and personal characteristics, prior drug and alcohol use and treatment programs, gun possession and use, and prison activities, programs, and services. Prior surveys of State prison inmates were conducted in 1974, 1979, 1986, 1991, and 1997. Sentenced federal prison inmates were interviewed in the 1991 and 1997 surveys.

To reduce respondent burden for the 2013 collection, the Census of Jails was combined with the Deaths in Custody Reporting Program (DCRP). The census provides the sampling frame for the nationwide Survey of Inmates in Local Jails (SILJ) and the Annual Survey of Jails (ASJ). Previous jail enumerations were conducted in 1970 (ICPSR 7641), 1972 (ICPSR 7638), 1978 (ICPSR 7737), 1983 (ICPSR 8203), 1988 (ICPSR 9256), 1993 (ICPSR 6648), 1999 (ICPSR 3318), 2005 (ICPSR 20367), and 2006 (ICPSR 26602). The RTI International collected the data for the Bureau of Justice Statistics in 2013. The United States Census Bureau was the collection agent from 1970-2006. The 2013 Census of Jails gathered data from all jail detention facilities holding inmates beyond arraignment, a period normally exceeding 72 hours. Jail facilities were operated by cities and counties, by private entities under contract to correctional authorities, and by the Federal Bureau of Prisons (BOP). Excluded from the census were physically separate temporary holding facilities such as drunk tanks and police lockups that do not hold persons after being formally charged in court. Also excluded were state-operated facilities in Connecticut, Delaware, Hawaii, Rhode Island, Vermont, and Alaska, which have combined jail-prison systems. Fifteen independently operated jails in Alaska were included in the Census. The 2013 census collected facility-level information on the number of confined and nonconfined inmates, number of inmates participating in weekend programs, number of confined non-U.S. citizens, number of confined inmates by sex and adult or juvenile status, number of juveniles held as adults, conviction and sentencing status, offense type, number of inmates held by race or Hispanic origin, number of inmates held for other jurisdictions or authorities, average daily population, rated capacity, number of admissions and releases, program participation for nonconfined inmates, operating expenditures, and staff by occupational category.

These data are part of NACJD's Fast Track Release and are distributed as they were received from the data depositor. The files have been zipped by NACJD for release, but not checked or processed except for the removal of direct identifiers. Users should refer to the accompanying readme file for a brief description of the files available with this collection and consult the investigator(s) if further information is needed.The data were obtained from one state prison system that was characterized by a diverse and rising prison population. This prison system housed more than 30,000 inmates across 15 institutions (14 men's facilities; 1 women's facility). The data contain information on inmates' placements into different housing units across all 15 state prison complexes, including designated maximum security, restrictive housing units. Inmates placed in restrictive housing were in lockdown the majority of the day, had limited work opportunities, and were closely monitored. These inmates were also escorted in full restraints within the institution. They experienced little recreational time, visitation and phone privileges, and few interactions with other inmates. The data contain information on inmates' housing placements, institutional misconduct, risk factors, demographic characteristics, criminal history, and offense information. These data provide information on every housing placement for each inmate, including the time spent in each placement, and the reasons documented by correctional staff for placing inmates in each housing unit. Demographic information includes inmate sex, race/ethnicity, and age. The collection contains 1 Stata data file "Inmate-Housing-Placements-Data.dta" with 16 variables and 124,942 cases.

This data collection provides information about topics and issues of concern in research and policy within the field of corrections. Chief among these are the characteristics of persons confined to state prisons, their current and past offenses, and the circumstances or conditions of their confinement. Also included is extensive information on inmates' drug and alcohol use, program participation, and the victims of the inmates' most recent offenses. This information, which is not available on a national basis from any other source, is intended to assist the criminal justice community and other researchers in analysis and evaluation of correctional issues.

In 2022, the incarceration rate of African Americans in local jails in the United States was *** incarcerations per 100,000 of the population -- the highest rate of any race or ethnicity. The second-highest incarceration rate was among American Indians/Alaska Natives, at *** incarcerations per 100,000 of the population.

This census provides information on county and municipal jails facilities in the United States and their administration. For all jails, the data include number of prisoners and their reason for being held, age and sex of prisoners, maximum sentence that could be served in the facility, facility capacity and age, types of security available, and operating expenditures. For jails in counties and municipalities with populations of 25,000 or more, data are supplied on quarterly jail population, age of cells, and availability of service facilities and programs for inmates.

Abstract (en): RECIDIVISM OF PRISONERS RELEASED IN 1994 is a database containing information on each of 38,624 sampled prisoners released from prisons in 15 states in 1994 and tracked for three years following their release. The majority of the database consists of information on each released prisoner's entire officially recorded criminal history (before and after the 1994 release). Sources for criminal history information are state and FBI automated RAP ("Records of Arrests and Prosecutions") sheets, which contain records of arrests, adjudications, and sentences. The study is the second major recidivism study conducted by the Bureau of Justice Statistics. The first study, RECIDIVISM AMONG RELEASED PRISONERS, 1983: UNITED STATES, tracked over 16,000 prisoners released in 11 states in 1983 for three years. These two studies are the closest approximation to "national" recidivism studies in the United States. They are distinguished by their large sample size (over 16,000 released prisoners in the first study, 38,624 in the second), geographic breadth of coverage (11 states in the first study, 15 in the second), length of prospective tracking (three years from date of release in both studies), ability to track the movement of released prisoners across state boundaries (both studies), and multiple measures of recidivism (both studies). Demographic data include race, ethnicity, sex, and date of birth. ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection: Created variable labels and/or value labels.; Standardized missing values.; Performed recodes and/or calculated derived variables.; Checked for undocumented or out-of-range codes.. Prisoners released during 1994 in the 15 states that the study covered. The 15 states account for about two-thirds of releases in the United States in a given year. Smallest Geographic Unit: state The following 15 state Departments of Corrections participated in the study: Arizona, California, Delaware, Florida, Illinois, Maryland, Michigan, Minnesota, New Jersey, New York, North Carolina, Ohio, Oregon, Texas, and Virginia. These departments supplied Bureau of Justice Statistics (BJS) with information on each person released from prison in the state in 1994 (Note: Illinois releases are for fiscal year 1994 rather than calendar year 1994). These 15 states were chosen as a purposive sample, based on willingness to participate, the state's relative contribution to the overall national prison population, and the state's inclusion in the earlier study of recidivism conducted by BJS in 1983 (see ICPSR 8875). The 15 states supplied BJS with release records on 302,309 prisoners released in 1994, approximately two-thirds of all prisoners released in the nation. Using these records, the researchers drew a representative sample from each state, totaling 38,624 out of the 302,309 released prisoners, stratified by most serious conviction offense. More detailed information regarding sampling procedures can be found in the codebook that accompanies this data collection. 2014-12-05 A minor change is made to the codebook.2012-01-12 For variable POTST, values for the state of New York were adjusted per the principal investigator.2011-03-08 All parts are being moved to restricted access and will be available only using the restricted access procedures.2009-02-09 Missing value codes were edited to correct for rounding and data entry errors.2007-03-02 The principal investigator revised the data so that there are 4,834 cases instead of 4,824 for values that are less than or equal to 90 for variable DCDV.2006-12-01 The principal investigator revised the description for variables RPRSD and RPRSITV in the codebook.2003-08-27 The principal investigator recoded some values in variables DCDV, RPRSD, RPRSITV, and RELTYP.2002-10-04 The principal investigator recoded some values (child victim age) in variable DCDV for 89 releases in the state of Virginia. Funding insitution(s): United States Department of Justice. Office of Justice Programs. Bureau of Justice Statistics.

The 2019 Census of State and Federal Adult Correctional Facilities (CCF) was the ninth enumeration of state institutions and the sixth enumeration of federal institutions sponsored by the Bureau of Justice Statistics and its predecessors. Earlier censuses were completed in 1979 (ICPSR 7852), 1984 (ICPSR 8444), 1990 (ICPSR 9908), 1995 (ICPSR 6953), 2000 (ICPSR 4021), 2005 (ICPSR 24642), and 2012 (ICPSR 37294). The 2019 CCF consisted of two data collection instruments - one for confinement facilities and one for community-based facilities. For each facility, information was provided on facility operator; sex of prisoners authorized to be housed by facility; facility functions; percentage of prisoners authorized to leave the facility; one-day counts of prisoners by sex, race/ethnicity, special populations, and holding authority; number of walkaways occurring over a one-year period; and educational and other special programs offered to prisoners. Additional information was collected from confinement facilities, including physical security level; housing for special populations; capacity; court orders for specific conditions; one-day count of correctional staff by payroll status and sex; one-day count of security staff by sex and race/ethnicity; assaults and incidents caused by prisoners; number of escapes occurring over a one-year period; and work assignments available to prisoners. Late in the data collection to avoid complete nonresponse from facilities, BJS offered the option of providing critical data elements from the two data collection instruments. These elements included facility operator; sex of prisoners authorized to be housed by facility; facility functions; percentage of prisoners authorized to leave the facility; one-day counts of prisoners by sex, and holding authority. Physical security level was an additional critical data element for confinement facilities. The census counted prisoners held in the facilities, a custody count. Some prisoners who are held in the custody of one jurisdiction may be under the authority of a different jurisdiction. The custody count is distinct from a count of prisoners under a correctional authority's jurisdiction, which includes all prisoners over whom a correctional authority exercises control, regardless of where the prisoner is housed. A jurisdictional count is more inclusive than a prison custody count and includes state and federal prisoners housed in local jails or other non-correctional facilities.

CAPITAL PUNISHMENT IN THE UNITED STATES, 1973-2018 provides annual data on prisoners under a sentence of death, as well as those who had their sentences commuted or vacated and prisoners who were executed. This study examines basic sociodemographic classifications including age, sex, race and ethnicity, marital status at time of imprisonment, level of education, and state and region of incarceration. Criminal history information includes prior felony convictions and prior convictions for criminal homicide and the legal status at the time of the capital offense. Additional information is provided on those inmates removed from death row by yearend 2018. The dataset consists of one part which contains 9,583 cases. The file provides information on inmates whose death sentences were removed in addition to information on those inmates who were executed. The file also gives information about inmates who received a second death sentence by yearend 2018 as well as inmates who were already on death row.

This is an Annotation for Transparent Inquiry (ATI) data project. The annotated article can be viewed on the publisher's website here. Project Summary Scholarship on human rights diplomacy (HRD)—efforts by government officials to engage publicly and privately with their foreign counterparts—often focuses on actions taken to “name and shame” target countries, because private diplomatic activities are unobservable. To understand how HRD works in practice, we explore a campaign coordinated by the US government to free twenty female political prisoners. We compare release rates of the featured women to two comparable groups: a longer list of women considered by the State Department for the campaign; and other women imprisoned simultaneously in countries targeted by the campaign. Both approaches suggest that the campaign was highly effective. We consider two possible mechanisms through which expressive public HRD works: by imposing reputational costs and by mobilizing foreign actors. However, in-depth interviews with US officials and an analysis of media coverage find little evidence of these mechanisms. Instead, we argue that public pressure resolved deadlock within the foreign policy bureaucracy, enabling private diplomacy and specific inducements to secure the release of political prisoners. Entrepreneurial bureaucrats leveraged the spotlight on human rights abuses to overcome competing equities that prevent government-led coercive diplomacy on these issues. Our research highlights the importance of understanding the intersection of public and private diplomacy before drawing inferences about the effectiveness of HRD. Data Generation We generated four sources of data for this project: 1. A dataset of political prisoners from 13 countries based on Amnesty International Urgent Action reports between 2000 and 2015. 2. Arrest and release information for a dataset of female political prisoners 3. A dataset on media attention based on both news articles from LexisNexis and online search trends from Google Trends 4. Interviews conducted with U.S. government officials and other human rights advocates involved in the #Freethe20 campaign to free political prisoners launched in September 2015 We used two sources of data for each of our two research questions. Our first research question was: Did the #Freethe20 campaign have an impact on the release rate of political prisoners? In an ideal world, we would have a comprehensive set of female political prisoners to compare with #Freethe20 prisoners. However, as we explain in the manuscript, in countries with more dire human rights situations, arrests often go unreported. In some cases, the sheer volume of political prisoners makes chronicling information about them challenging, if not impossible. Therefore, in order to construct a comparable set of cases, one strategy we used was to collect information from Amnesty International’s “Urgent Action” campaigns. To our knowledge, Amnesty International has the most comprehensive, publicly available list of contemporary political prisoners globally. Their records are public and searchable, which allowed us to construct a population of political prisoners from the countries targeted by the #Freethe20 campaign. We began our data collection with a base set of Urgent Actions metadata generated by Judith Kelley and Dan Nielson via webscraping from the Amnesty International website. Using a list of URLs that linked to each Urgent Action Report, we coded the name and sex of individuals featured in each Urgent Action Report from 2000 through September 2015 (the start of the #Freethe20 campaign) in the 13 countries featured in the campaign (Azerbaijan, Burma, China, Egypt, Ethiopia, Eritrea, Iran, North Korea, Russia, Syria, Uzbekistan, Venezuela, and Vietnam). Instructions about how we coded this information and sample documents are available in the QDR repository (QDR: MyrickWeinstein_codebook_urgentaction.pdf). After compiling a base dataset of individuals featured in Urgent Action reports, we identified the women in the dataset (~17% of entries) and conducted additional research about (1) whether these women could be classified as political prisoners, and (2) whether and when these women were released from prison, detention, or house arrest. Here, we relied on both follow-up reporting from Amnesty International as well as a variety of online news sources. We deposited the coding instructions for this process (MyrickWeinstein_codebook_releaseinfo.pdf) and also include documentation on additional online news sources that we used to make a judgment on a particular case. Our second question was: How and under what conditions did #Freethe20 affect the release rate of female political prisoners? To answer this question, we look at strategies of both public pressure and private, coercive diplomacy. For the former, we collected data on media attention and online search trends. We searched for newspapers and news articles that featured...

Due to a hardening of penal sensibilities and more stringent sentencing practices (mainly as a result of the 2003 Criminal Justice Act), a growing number of prisoners are serving extremely long life sentences from an early age. The UK has more life-sentenced prisoners per 100,000 of population than any other country in Europe (including Russia), and a higher proportion of life sentenced prisoners within its total sentenced prison population (10%) than any other European country or the US. The average minimum sentence length for mandatory life sentences has risen significantly in recent years. By the end of December 2018, there were 3,624 prisoners serving life sentences with tariffs of 10-20 years, and 1,862 with tariffs of more than twenty years (Ministry of Justice, 2019).

These prisoners have to endure and adapt to periods inside prison that are often longer than their lives as free citizens, while maturing into adulthood in an environment that does not allow, or is hardly conducive to, normal adult experiences. Following on from an earlier study of long-term imprisonment (grant: ES/J007935/1), undertaken from 2011-2014, this research constituted an unprecedented opportunity to enhance our understanding of the dynamics and effects of long-term confinement. Its primary aims were, first, to meet Kazemian and Travis's (2015) call for longitudinal insight into the experience, dynamics and effects of long-term confinement, including the ways in which the lives, priorities and relationships of people serving life sentences change over time; second, to focus more closely on some of the key themes and findings from our original study, in particular, the ways in which individuals engage reflexively with their sentence, their index offence and their sense of self; and, third, to explore the concept of the 'depth of imprisonment' - put simply, the relationship and polarity between the prison and the outside world - that is of particular relevance for this group of prisoners.

Interviews were undertaken, and surveys re-administered, with as many of our original sample as possible. Overall, this amounted to 120 of 146 initial participants, 100 in prison (out of 110 still in custody when fieldwork began) and 20 (out of 29) who had been released into the community on life licence.

The research offers insight into the nature and impact of long-term imprisonment, at a time when practitioners, pressure groups and policymakers are particularly interested in the custodial and post-custodial experiences of this expanding group. It contributes significantly to a sparse and outdated research literature on the experiences of life-sentenced prisoners, serving extremely long sentences. In doing so, it addresses fundamental questions about identity, coping and humanity under intense duress, and about the lived outcomes of the most extreme form of state punishment.

Due to a hardening of penal sensibilities and more stringent sentencing practices (mainly as a result of the 2003 Criminal Justice Act), a growing number of prisoners are serving extremely long sentences from an early age. The UK has more life-sentenced prisoners per 100,000 of population than any other country in Europe (including Russia), and a higher proportion of life sentenced prisoners within its total sentenced prison population (10%) than any other European country or the US. The average minimum sentence length for mandatory life sentences has risen significantly in recent years. By the end of December 2018, there were 3,624 prisoners serving life sentences with tariffs of 10-20 years, and 1,862 with tariffs of more than twenty years (Ministry of Justice, 2019).

These prisoners have to endure and adapt to periods inside prison that are often longer than their lives as free citizens, while maturing into adulthood in an environment that does not allow, or is hardly conducive to, normal adult experiences. Following on from an earlier study of long-term imprisonment (grant: ES/J007935/1), undertaken from 2011-2014, this research constituted an unprecedented opportunity to very significantly enhance our understanding of the dynamics and effects of long-term confinement. Its primary aims were, first, to meet Kazemian and Travis's (2015) call for longitudinal insight into the experience, dynamics and effects of long-term confinement, including the ways in which the lives, priorities and relationships of people serving life sentences change over time; second, to focus more closely on some of the key themes and findings from our original study, in particular, the ways in which individuals engage reflexively with their sentence, their index offence and their sense of self; and, third, to explore the concept of the 'depth of imprisonment' - put simply, the relationship and polarity between the prison and the outside world - that is of particular relevance for this group of prisoners.

Interviews were undertaken, and surveys re-administered, with as many of our original sample as possible. Overall, this amounted to 120 of 146 initial participants, 100 in prison (out of 110 still in custody when fieldwork began) and 20 (out of 29) who had been released into the community on life licence.

The research offers insight into the nature and impact of long-term imprisonment, at a time when practitioners, pressure groups and policymakers are particularly interested in the custodial and post-custodial experiences of this expanding group. It contributes significantly to a sparse and outdated research literature on the experiences of life-sentenced prisoners, serving extremely long sentences. In doing so, it addresses fundamental questions about identity, coping and humanity under intense duress, and about the lived outcomes of the most extreme form of state punishment.