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

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

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

Why GAO Did This Study