Center for Immigration studies 2009
* The Department of Homeland Security (DHS) estimates that immigrants (legal and illegal) comprise 20 percent of inmates in prisons and jails. The foreign-born are 15.4 percent of the nation’s adult population. However, DHS has not provided a detailed explanation of how the estimates were generated.
* Under contract to DHS in 2004, Fentress, Inc., reviewed 8.1 million inmate records from state prison systems and 45 large county jails. They found that 22 percent of inmates were foreign-born. But the report did not cover all of the nation’s jails.
* The 287(g) program and related efforts have found high rates of illegal alien incarceration in some communities. But it is unclear if the communities are representative of the country:
\* Maricopa County, Ariz.: 22 percent of felons are illegal aliens; \* Lake County, Ill.: 19 percent of jail inmates are illegal aliens; \* Collier County, Fla.: 20 to 22 percent of jail inmates and arrestees are illegal aliens; \* Weld County, Colo.: 12.8 to 15.2 percent of those jailed are illegal aliens.
* DHS states that it has identified 221,000 non-citizens in the nation’s jails. This equals 11 to 15 percent of the jail population. Non-citizens comprise only 8.6 percent of the nation’s total adult population.
* The Federal Bureau of Prisons reports that 26.4 percent of inmates in federal prisons are non-U.S. citizens. Non-citizens are 8.6 percent of the nation’s adult population. However, federal prisons are not representative of prisons generally or local jails.
* A Pew Hispanic Center study found that, of those sentenced for federal crimes in 2007, non-citizen Hispanics were 74 percent of immigration offenders, 25 percent of drug offenders, 8 percent of white collar offenders, and 6 percent of firearms offenders. Non-citizen Hispanics are 5.1 percent of the nation’s adult population. However, the report does not provide information for other crimes or for non-Hispanic immigrants.
* Recent reports by the Public Policy Institute of California (PPIC) and Immigration Policy Center (IPC) showing low rates of immigrant incarceration highlight the data problems in many studies. The 2000 Census data they used are not reliable.
* An analysis of the data used in the PPIC and IPC studies by the National Research Council found that 53 percent of the time the Census Bureaus had to make an educated guess whether a prisoner was an immigrant. The studies are essentially measuring these guesses, not actual immigrant incarceration.
* The poor quality of data used in the PPIC and IPC studies is illustrated by wild and implausible swings. It shows a 28 percent decline in incarcerated immigrants 1990 to 2000 — yet the overall immigrant population grew 59 percent. Newer Census data from 2007 show a 146 percent increase in immigrant incarceration 2000 to 2007 — yet, the overall immigrant population grew only 22 percent.
* The Survey of Inmates in State and Federal Correctional Facilities shows that 8.1 percent of prisoners in state prisons are immigrants (legal and illegal). However, the survey excludes jails and relies on inmate self-identification, which is likely to understate the number of immigrants.
* In 2009, 57 percent of the 76 fugitive murderers most wanted by the Federal Bureau of Investigation (FBI) were foreign-born. It is likely however that because immigrants can more readily flee to other countries, they comprise a disproportionate share of fugitives.
* Most studies comparing crime rates and immigration levels across cities show no clear correlation between the immigrant share of a city’s population and its level of crime. This is one of the strongest arguments that immigrants do not have high crime rates. However, such studies generally measure only overall crime, not crimes specifically committed by immigrants, so their value is limited. And a 2009 analysis by the Department of Homeland Security’s Office of Immigration Statistics found that crime rates were higher in metropolitan areas that received large numbers of legal immigrants, contradicting several older cross-city comparisons.
* From 1998 to 2007, 816,000 criminal aliens were removed from the United States because of a criminal charge or conviction. This is equal to about one-fifth of the nation’s total jail and prison population. These figures do not include those removed for the lesser offense of living or working in the country illegally. The removal and deportation of large numbers of criminal aliens may reduce immigrant incarceration rates because many will not return and re-offend, as is the case with many native-born criminals.
* Some have argued that the fall in national crime rates since the early 1990s is evidence that immigration may actually reduce crime. However, overall crime rates are affected by so many factors that it is a very poor way to examine a link between immigration and crime. The 1970s and 1980s saw crime rates rise along with immigration levels.