How do ICE detainers and 287(g) agreements differ in practice and legal effect?
Executive summary
ICE detainers are administrative requests that ask local jails to hold people beyond their release time so federal authorities can take custody, while §287(g) agreements deputize state or local officers to perform certain federal immigration functions under ICE supervision; the former is a unilateral administrative instrument and the latter is a formal delegated-authority program with training, oversight, and written memoranda [1] [2] [3]. In practice the two overlap—287(g) officers frequently prepare or issue detainers and exercise arrest/detention powers in jails—but they differ sharply in who exercises immigration authority, the contractual and statutory basis for action, and the downstream legal liability and political consequences for localities [4] [2] [3].
1. What an ICE detainer actually is, versus what 287(g) delegates
An ICE detainer is an administrative request asking a local law‑enforcement agency to hold an individual for up to 48 hours beyond the time they would otherwise be released so ICE can assume custody, and it is issued by ICE immigration officers or agents [1] [3]. By contrast, §287(g) is a statutory program created by the INA that allows ICE to enter Memoranda of Agreement with local or state agencies to delegate specified immigration officer functions—after a training and certification process—so designated local officers can interview, issue detainers, and prepare immigration paperwork themselves under ICE oversight [2] [4].
2. How they operate in the field: information, interrogation, and detention
In jurisdictions with 287(g), deputized jail or patrol officers may interrogate arrestees about immigration status, screen bookings against DHS databases, and issue detainers or even arrest and removal paperwork directly—turning routine local contacts into immigration enforcement moments—whereas in non‑287(g) places ICE may still place detainers based on federal investigation or database matches without delegating authority to local officers [3] [2] [5]. Secure Communities and other information‑sharing systems also allow local agencies to send biometric and booking data to ICE, prompting detainers even where no 287(g) agreement exists, so detainers can be a product of information flows as well as deputized action [5] [6].
3. Legal effect and liability: arrest power, custody, and constitutional risks
A detainer itself is an administrative request—not a federal warrant—and courts have found that holding someone beyond their lawful release on a detainer can be an unlawful arrest exposing localities to liability and settlements, so jurisdictions that comply run legal risk if they detain beyond the 48‑hour guidance or on faulty matches [1] [6]. §287(g) agreements, by contrast, formally authorize designated local officers to perform certain immigration functions, but DOJ and civil‑rights probes have found that some 287(g) implementations led to racial profiling and unconstitutional detentions, and ICE retains the authority to suspend MOAs for noncompliance—so deputization does not insulate agencies from constitutional or oversight consequences [7] [2] [3].
4. Costs, incentives, and the political economy
Local governments often absorb the financial and operational costs tied to both practices—detention bed time, staff, and transport—and advocates say 287(g) can effectively socialize deportation infrastructure onto county budgets while enabling contracts that rent jail space to ICE, a feature opponents argue creates perverse incentives to detain [8] [9]. Proponents frame 287(g) as a way to prioritize public‑safety removals, while critics point to evidence that many detainers and 287(g) actions involve misdemeanors or traffic offenses rather than serious crimes, highlighting a divergence between stated aims and outcomes [3] [10].
5. Policy debate, alternatives, and hidden agendas
Supporters of expanding 287(g) or encouraging detainer compliance often emphasize immigration control and local‑federal partnership, whereas civil‑rights groups, immigrant advocates, and some courts emphasize community trust harms, racial‑profiling findings, and legal exposure for localities; some states have explicitly barred or limited local cooperation to preserve public safety and avoid those harms, revealing a concurrent legal and political pushback to federal delegation efforts [8] [7] [5]. Behind the public arguments, incentives such as federal funding, detention‑bed contracts, and political pressure to appear “tough on immigration” shape why jurisdictions sign MOAs or honor detainers even when advocates warn of costs and rights violations [11] [8] [9].
6. Bottom line: overlapping tools, different mechanics and consequences
ICE detainers and §287(g) are distinct tools—one an administrative hold request, the other a delegated‑authority program—but in practice they reinforce one another: 287(g) deputization creates local actors who can generate and act on detainers, while detainer regimes and data‑sharing enable ICE to exercise control even without local deputization; both raise constitutional, financial, and community‑trust questions that have produced lawsuits, state restrictions, and ongoing policy fights [1] [2] [3] [8].