A major, large-scale study led by researchers at the University of California, Irvine has found no evidence that rising numbers of undocumented immigrants increase crime rates at the neighbourhood level. Instead, the analysis — spanning 10 years and some 11,500 neighbourhoods — shows declines in several crime categories where undocumented immigrant populations expanded most, while robberies increased.
Study design and headline findings
The research team examined crime statistics across a decade of data from 11,500 neighbourhoods to assess whether changes in the population of unauthorized immigrants were associated with criminal activity. The analysis is described by the authors as the first large-scale neighbourhood-level study of its kind.
Key findings included:
- No link between increases in undocumented immigrant populations and overall crime growth.
- Reductions in property crime and aggravated assaults in neighbourhoods that experienced the largest growth in undocumented residents.
- An observed increase in robberies in areas with growing undocumented populations; researchers say this likely reflects higher victimisation rather than greater offending by immigrants.
"Consistent with the research base more generally, unauthorized immigration doesn’t drive crime rates in U.S. neighborhoods," study author Charis E. Kubrin of UC Irvine said in a statement.
Context and implications
The findings add to a body of research dating back many decades that has repeatedly shown immigrants are not more likely to commit crime than native-born populations. The study’s authors cite historical work — notably a nearly century-old report from the Wickersham Commission — that previously concluded involvement in crime was lower among immigrants than among the native-born.
By drilling down to the neighbourhood level across a large sample, the study addresses claims often made in political and media debates that unauthorised immigration directly contributes to higher local crime rates. That argument was a prominent talking point in recent U.S. political discourse and featured among voters’ concerns during the 2024 presidential election.
Nuance on robberies
The increase in robberies in neighbourhoods with more undocumented immigrants introduces a nuanced element to the overall findings. The authors emphasise that the pattern does not necessarily indicate greater criminality among immigrants. Instead, they propose that undocumented immigrants may be disproportionately targeted as victims — a distinction with implications for policing strategies, community safety programs and social supports for vulnerable populations.
Explaining this nuance, the researchers wrote that an uptick in robberies ‘‘despite decreases in all other crime categories, would be consistent with the idea that undocumented immigrants are disproportionately likely to be targets of robbery given greater involvem[ent]’’ — an observation pointing to exposure and vulnerability rather than causation.
What the research does and does not say
The paper does not claim that all forms of crime fall uniformly where undocumented populations grow. Instead, it offers a differentiated view: several categories of crime declined while one category, robberies, rose. The study focuses on association at the neighbourhood level over time; it does not assert individual-level causation.
For policymakers and members of the public, the research suggests that immigration-related fears about rising crime lack empirical support at the community level for the majority of measured offences. It also highlights the importance of distinguishing between perpetrators and victims when crafting public safety responses and immigration policy.
| Crime category | Association with larger undocumented populations |
|---|---|
| Property crime | Decrease |
| Aggravated assault | Decrease |
| Robbery | Increase (likely reflecting victimisation) |
As with any large-scale empirical study, results should be interpreted alongside other research and local conditions. Nonetheless, the paper reinforces longstanding academic findings that immigration — including unauthorised immigration — is not a primary driver of elevated crime rates and underscores the need for targeted measures to protect vulnerable residents who may face heightened risk of victimisation.
