This study examines academic and government research on the question of immigrant crime. New government data indicate that immigrants have high rates of criminality, while older academic research found low rates. The overall picture of immigrants and crime remains confused due to a lack of good data and contrary information. However, the newer government data indicate that there are legitimate public safety reasons for local law enforcement to work with federal immigration authorities.

Among the findings:

• 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.