What federal laws and regulations authorize ICE to arrest and detain noncitizens?
Executive summary
ICE’s authority to arrest and detain noncitizens in the U.S. interior is grounded primarily in federal immigration statutes and implementing regulations — most centrally 8 U.S.C. § 1357 (authority to investigate, apprehend, and detain aliens) and provisions governing detention during removal proceedings such as 8 U.S.C. § 1226 — plus agency rules like 8 C.F.R. § 287.7 that authorize immigration detainers (multiple sources summarize this statutory framework) [1] [2] [3]. Courts and oversight reports repeatedly note that many ICE arrests are administrative (civil) arrests based on administrative warrants, not judicial warrants, and that enforcement practice is shaped by policies, intergovernmental agreements (e.g., 287(g)), and evolving DOJ/DHS guidance and court rulings [4] [5] [6].
1. The statutory skeleton: 8 U.S.C. § 1357 and related provisions
Congress gave immigration officers broad investigatory and arrest powers in the Immigration and Nationality Act. Analysts and legal primers identify 8 U.S.C. § 1357 as the primary source authorizing immigration officers to “investigate, apprehend, and detain” aliens for violations of immigration law; the CRS and other summaries treat this statute as central to interior enforcement [1] [2]. Section 1226 is repeatedly cited as the statutory basis for detaining noncitizens during removal proceedings and for setting bond and release procedures while those proceedings are pending [2].
2. Administrative warrants, not judicial warrants — how ICE’s arrests differ
ICE’s internal arrest practice relies largely on administrative arrest warrants issued within the agency rather than warrants signed by judges. Reporting and government analysis explain that ICE administrative warrants do not come from a magistrate; they are agency-issued upon a finding of probable cause that a person is removable [4] [2]. This distinction underlies ongoing legal debates and court scrutiny about the scope and constitutionality of warrantless or administrative arrests [4] [7].
3. Detainers and the regulatory hook: 8 C.F.R. § 287.7
When local jails or police have custody of someone, ICE often uses “immigration detainers” to request that those agencies hold the person for transfer to ICE. ICE says its authority to issue detainers comes from federal regulations at 8 C.F.R. § 287.7, which DHS ties to broader statutory powers under the INA [3]. Detainers are requests, not legal obligations for state or local agencies, and have been the focus of litigation and policy controversy [3].
4. State and local partnerships: 287(g), task forces, and delegation
Congress authorized delegation of some immigration functions to state and local officers under 8 U.S.C. § 1357(g). ICE’s 287(g) program trains and authorizes state/local personnel to perform certain immigration enforcement tasks — the program’s models include jail-based screening, task forces, and warrant service officers — and has been expanded sharply in recent years according to ICE and tracking reports [5] [8]. That delegation changes who may lawfully apprehend or hold a person for immigration purposes, and it has spurred political and legal controversy [5] [8].
5. Administrative discretion, detention standards, and bed space realities
ICE’s detention authority is coupled to prosecutorial and custody discretion. Migration Policy and other sources note ICE cannot detain all removable persons; detention practice is constrained by funding and bed capacity and supplemented by alternatives to detention such as supervised release programs [9]. ICE publishes detention standards and management rules (e.g., National Detention Standards, 6 C.F.R. Part 115) that govern conditions and oversight of facilities where noncitizens are held [10] [11] [12].
6. Legal limits, litigation, and court-imposed restrictions
Federal courts and consent decrees have limited aspects of ICE’s arrest powers where they found constitutional or legal violations. Reporting of recent rulings and settlements shows judges have required ICE to meet probable cause and flight-risk thresholds before warrantless interior arrests in some jurisdictions, and have ordered releases when policies were violated [7] [13] [14]. Such rulings demonstrate that statutory authority is practically constrained by Fourth Amendment and other legal protections as applied by courts [6] [7].
7. Points of disagreement and reporting gaps
Sources agree on the statutory anchors (§§ 1357, 1226 and regulatory provisions), but they differ on practice and emphasis: ICE presents arrests as statutory and mission-driven, emphasizing public-safety targets [15] [5], while legal scholars, nonprofits, and courts highlight limits on warrantless arrests and civil-rights risks [4] [7] [14]. Available sources do not mention a definitive single-page list of every statute and regulation authorizing every ICE action; rather, reporting points to a network of statutes, CFR provisions, internal policies, and delegated agreements that together authorize interior arrests and detention [1] [3] [2].
Limitations: this analysis uses only the supplied documents; for statutory text and the most recent judicial decisions, consult the cited agency pages, CRS primer, and court opinions referenced above [1] [2] [7].