
U.S. Immigration and Customs Enforcement (ICE) operates as the primary agency for immigration enforcement within the nation's interior, a role distinct from border security. A key instrument in its operations is the immigration detainer, a formal request sent to federal, state, and local law enforcement agencies to hold individuals for up to 48 hours beyond their scheduled release time. This procedure is intended to provide ICE agents with a window to assume custody of noncitizens believed to be subject to removal.
According to official ICE guidance on immigration detainers, these requests are issued for individuals arrested on criminal charges who ICE has probable cause to believe are removable from the United States. The process typically begins after an individual's fingerprints are shared with federal databases upon a local arrest, flagging them for potential immigration enforcement action. The detainer, formally known as Form I-247A, asks the holding agency to notify ICE of the impending release and to maintain custody of the individual for the additional two-day period.
However, the use of detainers is a focal point of legal and political controversy. Civil rights organizations and legal experts argue that honoring these requests without a judicial warrant can lead to violations of the Fourth Amendment, which protects against unreasonable seizures. Multiple federal courts have affirmed that detainers are voluntary requests, not mandatory orders. This has led to a patchwork of policies nationwide, with hundreds of counties and cities adopting policies that limit or deny cooperation with ICE detainer requests, as highlighted in various legal analyses of immigration detainers.
The friction between federal objectives and local autonomy underscores the complexities of interior immigration enforcement. Advocacy groups report instances of individuals with protected status or valid legal claims being targeted, which they argue erodes trust between immigrant communities and local police. These enforcement actions are seen by critics as overly broad, creating a climate of fear that may deter individuals from reporting crimes. The ongoing debate reflects a fundamental tension between federal immigration priorities and the constitutional rights and public safety concerns managed by local jurisdictions.



