The Evidence on Illegal Immigration and Crime


Jonathan Haggerty
Former Resident Fellow, Criminal Justice & Civil Liberties

Key Points

Research suggests there is little connection between immigration and crime; and, to the extent any such relationship exists, immigration reduces crime rates. But there is less research specifically on illegal immigration and crime.

Recent research, however, shows that illegal immigrants are significantly less likely than native-born Americans to be arrested, convicted and incarcerated. Evidence also suggests illegal immigrants have a beneficial effect on crime as they tend to bring down crime rates in their communities.

Policymakers should rethink enforcement policies based on the misconception that illegal immigrants bring with them a wave of violent crime. Instead, they should implement policies that allow law enforcement the discretion to pursue the most dangerous immigration violators, and provide avenues for law-abiding and hardworking immigrants to earn or regain legal status.

Press Release

Ignore What You’ve Heard, Immigration Actually Improves Crime Rates


Research suggests there is little connection between immigration and crime; and, to the extent any such relationship exists, immigration reduces crime rates. One frequently cited example—an analysis of 51 studies on immigration and crime conducted between 1994 and 2014—showed that the relationship between immigration and crime is either nonexistent or negative, which means that immigration appears to reduce crime rates. Nonetheless, immigration and crime—specifically related to Latin American gang members—was a major theme of the 2016 presidential election, as opposition to immigration was fundamental to then-candidate Donald Trump’s campaign.

Because much of the opposition to immigration stems from a conviction that immigrants are uniquely prone to crime, it is important to review the current evidence. This paper looks specifically at the evidence on illegal immigration and crime, as many supporters of President Trump claim to only oppose illegal immigration, and not immigration itself. There is limited research on the crime rates of illegal immigrants due to data restrictions; however, much of the current, impressive body of evidence that suggests immigrants commit crime at lower rates than native-born Americans combines data on legal and illegal immigrant populations.

The most frequently cited studies specifically on illegal immigration can be divided into two categories: those looking at institutionalization rates—the rate at which a given population is arrested or incarcerated—and experimental studies measuring illegal immigration’s impact on crime rates in particular geographic areas. Both categories suggest that illegal immigrants commit crimes at lower rates than native-born citizens. Of the nineteen studies examined in this policy brief, only one suggested a higher crime rate for illegal immigrants, while the rest suggested that illegal immigrants commit fewer crimes than native-born Americans, that they have no effect on crime rates or that they decrease crime rates in areas where they settle. These findings are largely consistent with the overall empirical evidence on immigration and crime.

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