An ICE detainer—or “immigration hold”—is one of the key tools U.S. Immigration and Customs Enforcement (ICE) uses to apprehend individuals who come in contact with local and state law enforcement agencies and put them into the federal deportation system. An ICE detainer is a written request that a local jail or other law enforcement agency detain an individual for an additional 48 hours (excluding weekends and holidays) after his or her release date in order to provide ICE agents extra time to decide whether to take the individual into federal custody for removal purposes.

ICE’s use of detainers to imprison people without due process and, in many cases, without any charges pending or probable cause of any violation has raised serious constitutional concerns. In November 2014, the Secretary of the Department of Homeland Security acknowledged “the increasing number of federal court decisions that hold that detainer-based detention by state and local law enforcement agencies violates the Fourth Amendment.” The secretary directed ICE to limit its use of detainers going forward, but serious questions remain about whether and how ICE’s practices will change on the ground.

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