How do crime rates for undocumented immigrants vary by state or sanctuary city policies in 2025?

1. What the bulk of research reports: lower or comparable offending, not higher

Multiple peer-reviewed and policy‑research summaries conclude immigrants—including undocumented immigrants where research isolates them—tend to have lower criminal offending and arrest rates than U.S.-born citizens, and large-sample studies find no evidence that undocumented immigration increases violent crime at the state or national level ^{[1] [4] [7]}. Meta‑analyses and national‑level work cited by Migration Policy Institute and other analysts repeatedly report either comparable or lower rates of violent and property crime in places with higher immigrant concentrations ^{[1] [2]}.

2. Sanctuary policies: no detectable increase in crime; some studies find improvements

Multiple research reviews and legal‑policy organizations report that sanctuary policies do not lead to higher crime rates, and some studies even link welcoming policies to modest reductions in certain crimes and civic benefits like greater trust in policing ^{[2] [8] [3]}. The National Academy of Sciences analysis cited by the American Immigration Council found that sanctuary policies changed the composition of deportations but did not increase local crime rates or prevent deportations of people with violent convictions ^[9].

3. Why people see different pictures: data, definitions, and enforcement choices

Disagreement often stems from what is being measured—local arrests, federal convictions, or ICE detainers—and who is included in the denominator; federal press releases highlighting arrests or detainers can be presented as proof of immigrant crime waves even though local arrest records and federal conviction datasets are not identical measures of population crime rates ^{[5] [6]}. Researchers caution that rare but highly public violent incidents by undocumented individuals receive outsized media and political attention, skewing public perception relative to population‑level statistics ^[3].

4. State variation and political responses matter more than simple geography

Crime outcomes do vary across states and cities, but evidence does not show a consistent pattern that sanctuary jurisdictions are more dangerous; instead, differences in crime rates more closely track broader socioeconomic conditions, policing practices, and enforcement policies than sanctuary status per se ^{[10] [2]}. Political actors have used localized ICE enforcement counts to argue sanctuary jurisdictions attract people with criminal histories, while journalists and researchers note that ICE arrest totals reflect enforcement targeting and are spread nationally—not proof of sanctuary‑driven crime increases ^{[6] [5]}.

5. Practical conclusion and limits of the evidence for 2025

Based on peer‑reviewed studies and policy analyses up to and including 2025, the best available evidence is that undocumented immigrants do not raise crime rates and that sanctuary policies do not cause increased violent or property crime; some research even ties sanctuary approaches to improved public safety outcomes through stronger community‑police trust ^{[1] [3] [8]}. At the same time, measuring crime among undocumented populations remains methodologically tricky—metrics differ (arrests vs convictions), federal vs local datasets diverge, and rapid policy shifts or enforcement operations can change detection rates—so claims that sanctuary laws unequivocally “cause” higher crime are not supported by the cited empirical literature ^{[4] [5] [11]}.