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Criminal Alien Statistics: Information on Incarcerations, Arrests, Convictions, Costs, and Removals

GAO-18-433 Published: Jul 17, 2018. Publicly Released: Aug 16, 2018.
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Highlights

What GAO Found

From fiscal years 2011 through 2016, the criminal alien proportion of the total estimated federal inmate population generally decreased, from about 25 percent to 21 percent (as shown in the figure below). During this period, the estimated number of criminal aliens incarcerated in federal prisons decreased from about 50,400 to about 39,500, or 22 percent. Ninety-one percent of these criminal aliens were citizens of one of six countries, including Mexico, Honduras, El Salvador, Dominican Republic, Colombia, and Guatemala.

Estimated Number of Individuals, by Citizenship, Incarcerated in Federal Prisons from Fiscal Years 2011 through 2016

HL_5 - 101021

Based on data from the Department of Justice's (DOJ) State Criminal Alien Assistance Program (SCAAP), which reimburses states and localities for a portion of criminal alien incarceration costs, the number of SCAAP criminal alien incarcerations in state prisons and local jails that received SCAAP reimbursements also decreased from about 282,300 in fiscal year 2010 to about 169,300 in fiscal year 2015, or 40 percent. The decrease can be attributed to (1) general declines in the number of SCAAP criminal alien incarcerations in each of the participating state prisons and local jails that participated in SCAAP, and (2) a reduction in the number of states and localities that participated in SCAAP. Seventy-six percent of SCAAP criminal alien incarcerations in fiscal year 2015 were born in one of six countries, including Mexico, El Salvador, Honduras, Guatemala, Cuba, and Germany.

Based on a random sample of criminal aliens incarcerated in federal prisons during fiscal years 2011 through 2016 and based on a random sample of SCAAP criminal aliens incarcerated in state prisons and local jails during fiscal years 2010 through 2015, GAO estimated the following:

  • The approximately 197,000 federal criminal aliens included in GAO's analysis were arrested/transferred about 1.4 million times for approximately 2 million offenses from over 43 years (from 1974 through 2017); 42 percent of the offenses that these criminal aliens were arrested for were related to immigration and 26 percent were related to drugs or traffic violations.

  • The approximately 533,000 SCAAP criminal aliens included in GAO's analysis were arrested/transferred about 3.5 million times for approximately 5.5 million offenses from over 53 years (from 1964 through 2017); 52 percent of the offenses that these SCAAP criminal aliens were arrested for were related to traffic violations, drug offenses, or immigration offenses.

An arrest does not necessarily result in prosecution or a conviction of all, or any, of the offenses for which an individual is arrested. GAO's analyses found that 92 percent of the criminal aliens incarcerated in federal prison from fiscal years 2011 through 2016 were convicted of primary offenses related to immigration or drugs—a primary offense is the one with the longest maximum sentence, as determined by the relevant agency. At the state level, SCAAP criminal aliens incarcerated in fiscal year 2015 in Arizona, California, Florida, New York, and Texas state prison systems were convicted of various primary offenses. While the most common primary offenses varied by each of the five states, they generally related to drug, homicide, or sex offenses.

GAO's analyses found that the total annual estimated federal costs to incarcerate criminal aliens decreased from about $1.56 billion to about $1.42 billion from fiscal years 2010 through 2015. These costs included federal prison costs and reimbursements to state prison and local jail systems for a portion of their costs. GAO's analyses also show that selected annual estimated operating costs of state prison systems to incarcerate SCAAP criminal aliens decreased from about $1.17 billion to about $1.11 billion from fiscal years 2010 through 2015. These selected costs included correctional officer salaries, medical care, food service, and utilities.

Of the approximately 165,700 criminal aliens who completed a term of incarceration in federal prison from fiscal years 2011 through 2016, about 157,400 or 95 percent were subsequently removed from the United States by the Department of Homeland Security (DHS). The majority (about 146,500) of the criminal aliens who completed a term of federal prison incarceration did not have a subsequent reincarceration in a federal prison. However, about 19,300 were subsequently reincarcerated in a federal prison at least once and about 5,500 were reincarcerated in a state prison or local jail system that received SCAAP funding. These experiences after federal prison incarceration are not mutually exclusive. For example, criminal aliens could have been removed from the United States by DHS after their incarceration in federal prison, then reentered the United States and subsequently become reincarcerated in either a federal or state prison or local jail.

Federal Prison Reincarcerations of Criminal Aliens, Fiscal Years 2011 through 2016

Number of federal prison reincarcerations

Number of criminal aliens

Percent

0

146,500

88.4

1

16,700

10.1

2

2,200

1.3

3

300

0.2

4 or more

100

0.1

Totala

165,700

100

Why GAO Did This Study 

As of 2014, DHS estimated the total alien—a person who is not a citizen or national of the United States—population in the United States was about 27.1 million. Members of the alien population that have been arrested and convicted of crimes in the United States are referred to as criminal aliens. The costs associated with incarcerating criminal aliens are borne by the federal government, states, and localities. GAO was asked to update its March 2011 report on criminal alien statistics.
 
This report addresses, among other things, the (1) number and nationality of incarcerated criminal aliens, (2) number of criminal alien arrests and convictions, (3) estimated costs associated with incarcerating criminal aliens, and (4) experiences of criminal aliens after incarceration in federal prison.
 
GAO analyzed the most recent data available on criminal aliens, generally from fiscal years 2010 through 2016. Specifically, GAO analyzed data for criminal aliens incarcerated in federal prisons from fiscal years 2011 through 2016, and this group is the federal criminal alien population studied for this report. GAO also analyzed data for certain criminal aliens incarcerated in state prisons and local jails that received SCAAP funding from fiscal years 2010 through 2015, and this group is referred to as the state and local study population reviewed for this report. SCAAP data represents a portion of all criminal aliens incarcerated in state prisons and local jails. GAO used SCAAP data because there are no reliable data available on all criminal aliens incarcerated in every U.S. state prison and local jail.
 
GAO analyzed (a) DOJ data on criminal alien incarcerations, arrests, convictions, and costs; (b) conviction data from the five state prison systems with the largest number of SCAAP criminal alien incarcerations in fiscal year 2015; and (c) DHS data on removals.
 
For its arrest analyses, GAO selected generalizable random samples of (1) 500 criminal aliens from about 197,000 that were incarcerated in federal prisons from fiscal years 2011 through 2016 and (2) 500 SCAAP criminal aliens from about 533,000 that were incarcerated in state prisons and local jails from fiscal years 2010 through 2015. These samples included only those criminal aliens who had a Federal Bureau of Investigation (FBI) number—a unique identifier. This unique identifier allowed GAO to obtain arrest/transfer histories for these criminal aliens from FBI’s database, which includes data from law enforcement agencies across the nation.
 
While the samples selected for the arrest analyses allowed GAO to estimate and provide insights about the arrest history of the criminal aliens in the study populations, these findings are not generalizable to the arrest history of criminal aliens not included in these populations. These data did not allow GAO to distinguish between a new arrest and a transfer from one agency to another; therefore, these are collectively referred to as “arrests/transfers.” An arrest/transfer can be for multiple offenses. GAO’s arrest analyses have a margin of error of plus or minus 7 percentage points or fewer.
 
For GAO’s analyses of state conviction data, information obtained from the selected state prison systems is not generalizable to all state prison systems, but provides useful insights on why criminal aliens were incarcerated.
 
For more information, contact Gretta L. Goodwin at (202) 512-8777 or goodwing@gao.gov.
 

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Topics

ArrestsCitizenshipConvictionsCorrectional facilitiesImmigration enforcementCriminal investigationsFederal prisonsFederal spendingImmigrantsImmigrationImprisonmentLaw enforcementSentencingState prisons