How do state and local “sanctuary” policies affect ICE arrest and conviction statistics reported by DHS?
Executive summary
Sanctuary policies measurably reduce the number of people that ICE is able to arrest and remove, primarily by preventing local jails from honoring ICE detainers and thereby changing the composition of enforcement toward more community arrests [1] [2]. Multiple empirical studies find sanctuary laws lower overall removals without increasing local crime and do not substantially reduce deportations of people with violent convictions, while federal agencies frame headline arrest statistics to emphasize criminality—a framing that mixes convictions, pending charges, and reentry cases in ways that complicate comparison [1] [3] [4] [5].
1. How sanctuary rules change the raw numbers—fewer detainer-enabled deportations
When local jurisdictions adopt policies that refuse to honor ICE detainers or limit cooperation, researchers find a roughly one-third reduction in deportations in studied periods because jails no longer hold people for ICE pickup, and ICE therefore arrests and deports fewer people overall [1]. Independent analysts and advocacy groups corroborate that local noncooperation shifts the locus of enforcement away from jails and can cut deportations of people without criminal convictions by roughly half in some studies, altering DHS aggregate removal totals [3] [2].
2. Not all categories move the same—composition, not universal immunity
Sanctuary policies tend to change who is removed rather than create blanket protections: studies report little to no decline in deportations of people convicted of violent crimes because many sanctuary policies carve out exceptions for serious offenders and ICE policy prioritization has historically targeted serious convictions [1] [3]. At the same time, ICE arrest datasets and independent FOIA-derived compilations show that large shares of ICE arrests include people with no convictions or only pending/ minor charges, a fact that sanctuary policies most strongly affect [4] [2].
3. DHS statistics and the politics of classification
DHS and ICE frequently present arrest figures framed around “criminal arrests,” but those tallies commonly bundle convictions, pending charges, reentry after removal, and administrative immigration violations—categories that advocacy researchers argue overstate the share of people with proven violent convictions [5] [4]. The department’s public statements and press releases can be highly political—e.g., emphasizing detainer counts in a single city or asserting high percentages of arrestees with criminal histories—while not always clarifying how many arrests stem from local jail cooperation versus community apprehensions [6] [7].
4. ICE operational response—more community arrests and reliance on federal tools
Where jails will not hold people for ICE, the agency often adapts by conducting more “community arrests” outside jails and by leveraging border and reentry enforcement to meet removal targets, which can raise the visible number of arrests even as jail-facilitated removals decline; Bay Area reporting documented a rise in arrests where nearly half of those arrested had no criminal conviction [8] [2]. Academic and investigative reporting also documents ICE’s institutional dependence on local arrests and the significance of jail cooperation to sustain large-scale removals, so reduced cooperation constrains volumes and shifts operational tactics [2] [9].
5. Crime and public-safety outcomes—evidence against the “violent criminals” claim
Multiple peer-reviewed analyses find no detectable increase in local crime associated with sanctuary adoption and show sanctuary jurisdictions do not experience declines in removals of people with violent convictions; some county-level work even links noncooperation with equal or lower crime and better economic indicators, contradicting claims that sanctuary policies produce public-safety harms [1] [3] [9]. That counter-evidence raises questions about federal claims that sanctuary rules are directly responsible for dangerous people evading deportation, though those claims are advanced in DHS communications [6] [7].
6. Caveats, data limits, and political incentives
The empirical picture depends on definitions (conviction vs. pending charge vs. immigration violation), the time window examined, and the extent to which local policies include exceptions or informal cooperation—limitations that researchers and datasets explicitly acknowledge [1] [4] [10]. Readers should note the competing incentives: local jurisdictions emphasize community trust and costs of cooperation, advocacy researchers highlight reductions in mass deportation, and federal agencies emphasize criminality to justify enforcement—each framing shapes which ICE arrest and conviction statistics get reported and how they are interpreted [11] [6].