An ICE detainer (Form I‑247/I‑247A) is an administrative request from ICE asking a jail or police agency to: (a) notify ICE before an individual in custody is released and/or (b) hold that person for up to 48 hours beyond the time they would otherwise be released so ICE can assume custody. It is not itself a federal arrest warrant; it is issued under 8 C.F.R. §287.7 and is legally a request rather than a compulsory order. Jurisdictions can decline to honor detainers (many do) because holding someone solely on a detainer can raise Fourth Amendment and liability concerns; ICE policy also says detainers should not change local custody decisions like bail, classification, or parole.
New York City: Local law limits honoring ICE detainers without a judicial warrant and requires service of any detainer on the subject; NYC policy generally bars the NYPD and DOC from holding people beyond release solely on civil immigration requests unless there is a signed judicial warrant. New York State: currently prohibits state and local agencies from using state resources to carry out most civil immigration enforcement and, in proposed/advocated legislation (e.g., "New York For All"), would bar deputization and require judicial warrants for transfers to ICE; practices vary by county. Exact scope depends on the particular local rule or state statute/policy in force.
A federal arrest warrant from the U.S. District Court (SDNY) is a judicially issued warrant that authorizes federal officers to arrest the named person anywhere in the United States; local police may rely on and execute federal warrants and typically must comply with them. A federal criminal warrant carries more legal authority to detain than an ICE administrative detainer because it is issued by a judge based on probable cause.
A “final order of removal” is a judicial or administrative determination that an individual is removable from the U.S. (final Decision of an Immigration Judge or Board of Immigration Appeals) and triggers ICE authority to detain and remove the person. After issuance the government typically schedules and carries out physical removal (deportation), may seek to detain the person pending removal, and can use that final order as the statutory basis for future detainers and admission bars.
Reentry after removal commonly occurs when someone crosses the border illegally or with fraudulent documents, or when identity/authentication gaps prevent detection; contributing gaps include limited border resources, falsified or stolen travel documents, lack of biometrics linkage in databases, and variations in record-sharing between agencies and countries. Smugglers also help people avoid detection; reentry after removal is a criminal offense (illegal reentry) but is still relatively common.
DHS/ICE press releases and related DHS materials state the counts (e.g., 6,947 released since Jan. 20; 7,113 with active detainers) come from ICE/ERO operational databases and local custody reporting; however the DHS release does not publish the underlying dataset or methodology in detail. Independent verification requires access to ICE ERO detention/detainer records or state/local jail booking data; DHS did not in the press release provide a line‑by‑line methodology or public dataset, so external verification is limited.
Manhattan Central Booking is New York City’s central intake/processing facility for people arrested by the NYPD; it handles classification, fingerprints, booking records and holds pretrial detainees before arraignment. When ICE submits a detainer or federal warrant, Central Booking is where the detainer/warrant is presented, copies served, and (if honored) ICE can assume custody there; it’s also where the question of holding someone for up to 48 hours would be operationalized.