What peer-reviewed studies compare homicide rates between undocumented immigrants and U.S.-born residents?
Executive summary
The strongest peer-reviewed comparison comes from a 2020 paper in the Proceedings of the National Academy of Sciences that used Texas arrest records to compare criminality across undocumented immigrants, legal immigrants, and U.S.-born residents and reported substantially lower homicide arrest rates for undocumented immigrants than for U.S.-born citizens [1] [2]. Other peer-reviewed work examines immigration and violent crime more broadly or looks at foreign-born victimization rather than perpetration; methodological limits—most importantly the use of arrest or conviction records as proxies for actual offending and the uniqueness of Texas data—shape what can be concluded from the literature [3] [4] [5].
1. The PNAS Texas study: the central peer‑reviewed comparison
The PNAS study “Comparing crime rates between undocumented immigrants, legal immigrants, and native‑born US citizens in Texas” analyzed Texas Department of Public Safety arrest data from 2012–2018, used Center for Migration Studies population estimates for undocumented counts, and found that undocumented immigrants had a lower homicide arrest rate (roughly 1.9 per 100,000) than U.S.-born citizens (about 4.8 per 100,000) over that period, a gap of more than half in favor of lower rates among the undocumented population [1] [2] [6]. The National Institute of Justice summarized these results, noting undocumented arrest rates were less than half for violent crimes overall and specifically highlighted the homicide findings while cautioning homicide rates fluctuate because murders are relatively rare [3].
2. Broader peer‑reviewed research on immigration and violent crime
Peer‑reviewed studies that take a national or multi‑city view generally find no clear link between increased undocumented immigration and rising violent crime and at times find immigrant presence is associated with lower violence; for example, work using survey and administrative data to examine whether undocumented immigration increases violent crime concludes null or negative associations, and these studies discuss measurement concerns such as nonresponse and the residual methods for estimating undocumented populations [4] [7]. Migration Policy Institute and other syntheses cite a growing body of research showing immigrants commit crimes at lower rates than the U.S.-born, though many of those syntheses aggregate across documented and undocumented groups rather than isolating undocumented offenders [7].
3. Studies of foreign‑born homicide victimization — a different angle
Several peer‑reviewed articles use the National Violent Death Reporting System to characterize homicide victims who are foreign‑born, finding, for instance, that roughly 8% of homicide victims in a 2017 multi‑state NVDRS sample were foreign‑born and that victimization patterns differ in ways that merit attention, but these studies address victim risk and circumstances rather than directly measuring undocumented perpetrators’ homicide rates [5] [8]. These victim‑focused analyses underscore an important analytic distinction: research on victims illuminates immigrant exposure to violence but does not substitute for population‑based comparisons of offending by legal status.
4. Methodological caveats and contested, non‑peer‑reviewed findings
The Texas PNAS result depends on a distinctive data environment—Texas collects biometric indicators linked to immigration status for arrestees—and on population estimates (CMS residual method); authors and funders note arrests are an imperfect proxy for offending and that many homicides go unsolved, complicating rate comparisons [1] [3] [9]. Non‑peer‑reviewed analyses and think‑tank reports have reached different conclusions (for example, competing Cato Institute or Crime Prevention Research Center reports), and media fact checks have emphasized that peer‑reviewed academic work does not support claims that thousands of homicide victims annually are attributable to undocumented immigrants [6] [1]. These alternative sources often reflect ideological agendas—libertarian or pro‑restriction think tanks—that should be weighed against peer‑reviewed methods and transparency [1] [6].
5. What remains unanswered and where evidence is strongest
Peer‑reviewed evidence that directly compares homicide offending by undocumented versus U.S.-born residents is sparse beyond the Texas PNAS analysis, and national generalizations require caution because of data gaps, measurement choices, and the difference between arrests/convictions and true offending; syntheses and multiple peer‑reviewed studies converge, however, on the broader point that immigrants as a group are not associated with higher violent crime and often have lower arrest/incarceration rates than the U.S.-born [1] [7] [4]. Where the literature is strongest is in showing lower arrest and incarceration rates among immigrants overall and in providing a methodological roadmap—using administrative records plus careful population denominators—for future research that might replicate Texas‑style findings in other states [3] [2].