How do local policies on jailholds and ICE notifications affect the composition of people ICE arrests in different counties?
Executive summary
Local policies that limit jailholds and restrict notifications to Immigration and Customs Enforcement (ICE) systematically reduce the number and change the makeup of people ICE arrests: counties that deny ICE access to booked detainees or refuse to honor administrative "detainers" see fewer arrests drawn from jail populations and a higher share of so‑called “at‑large” community arrests by ICE, while jurisdictions that allow ICE entry into jails or sign cooperative agreements become sources of a larger share of arrests of people already detained for low‑level offenses [1] [2] [3].
1. How jailhold and notification rules operate in practice
Many counties either have explicit policies that prohibit ICE from entering jails to arrest people without a criminal warrant, or they refuse to comply with ICE “detainers” — requests to hold someone beyond release so federal agents can take custody — and instead release people immediately unless under a valid criminal hold; conversely, jurisdictions that permit ICE access or informal collaboration facilitate direct federal apprehensions inside lockups, turning jails into de facto recruitment pools for ICE arrests [2] [4] [3].
2. The direct mechanism shaping arrest composition
When local jails honor ICE holds or allow on‑site arrests, a large share of ICE bookings come from people initially detained for traffic stops, misdemeanors or other low‑level contact with local law enforcement; Vera’s long‑range tally shows local jails are the most common facilities used by ICE, creating an incentive for jurisdictions to feed detainees into federal immigration processing [3] [5]. By contrast, in counties that bar jail access or refuse detainers, ICE must pursue community or “at‑large” operations — door knocks and workplace or street arrests — shifting the arrested population toward people not already in custody [1] [4].
3. Evidence from recent analyses and data patterns
State and county variation in ICE arrest counts aligns with local cooperation regimes: analyses note Northern California’s low ICE arrest rate is linked to California’s sanctuary law and local resistance, and nearly half of Bay Area arrests shifted toward people without convictions as ICE increased community apprehensions to meet enforcement targets [6]. National reporting documents that the recent federal shift away from jails toward at‑large apprehensions materially changed who is being arrested — increasing non‑custodial, community arrests — while prison‑policy counts and ICE’s own field office structure explain why places that partner with ICE register higher in‑custody arrest tallies [1] [2] [7].
4. Who is affected: criminal history and geography
Data show a substantial fraction of people ICE detains nationwide have no criminal convictions, and county jails disproportionately supply detainees to ICE when local cooperation exists; TRAC and other counts report large shares of detained people without convictions, underscoring that jail‑based access draws in many non‑serious offenders for immigration processing [8] [5]. Geographic idiosyncrasies matter too: ICE’s 25 ERO field offices and a handful of state‑level offices shape local partnerships, so statewide policies and the stance of local sheriffs can create sharp county‑to‑county differences in who is arrested [7] [2].
5. Incentives, political drivers, and alternate explanations
Scholars find that political alignment and state policy are strong predictors of where ICE arrests rise, suggesting motivations beyond crime control — enforcement priorities track rhetoric and intergovernmental cooperation choices — and critics warn that reliance on jail contracts creates perverse incentives for localities to expand capacity for federal dollars [9] [3] [5]. An alternative view is that ICE tactical shifts (from jails to street operations) reflect operational aims to increase deportations rapidly rather than local policy alone; both dynamics operate together, so county rules constrain one major pathway but do not eliminate arrests entirely [1] [7].
6. Consequences and accountability questions
The upshot is a territorial tug‑of‑war: counties that protect detainee release and bar detainers blunt ICE’s ability to pull people out of the criminal legal system, changing the arrested population’s composition and forcing ICE into riskier community tactics that raise civil‑liberties challenges; where cooperation exists, jails remain a steady pipeline of arrests, amplifying detention numbers and drawing in many without convictions, which raises oversight and public‑policy questions about incentives and human costs [3] [8] [4]. Reporting limitations prevent precise quantification of county‑level causal effects here without more granular, matched datasets of jail policies, detainer compliance, and ICE arrest logs [2] [7].