Immigration Enforcement

Introduction

Immigration enforcement encompasses the laws, policies, and practices by which the United States controls its borders and enforces compliance with immigration laws within the interior. Enforcement is carried out primarily by the Department of Homeland Security (DHS), including Customs and Border Protection (CBP) at the border and Immigration and Customs Enforcement (ICE) in the interior. Immigration enforcement has become one of the most politically charged areas of American law, with ongoing debates about enforcement priorities, due process, and federalism.

Customs and Border Protection

Customs and Border Protection (CBP) is the largest federal law enforcement agency and is responsible for securing US borders. CBP inspects persons and goods entering the United States at ports of entry, patrols the borders between ports of entry, and enforces immigration and customs laws at the border. CBP officers have broad inspection authority, including the ability to search persons and property at the border under the border search exception to the Fourth Amendment.

The U.S. Border Patrol, a component of CBP, is responsible for enforcement between ports of entry. Border Patrol agents apprehend persons who enter the United States without inspection and interdict contraband. The legal framework for border enforcement includes both immigration law and criminal law, as illegal entry is a criminal offense under 8 USC § 1325.

Immigration and Customs Enforcement

Immigration and Customs Enforcement (ICE) is responsible for interior immigration enforcement. ICE identifies, arrests, and removes noncitizens who are subject to removal. ICE Enforcement and Removal Operations (ERO) execute removal orders and manage detention facilities. ICE Homeland Security Investigations (HSI) investigates immigration-related crime, including human trafficking and document fraud.

ICE enforcement priorities have varied significantly across administrations. The Priority Enforcement Program (PEP) and its predecessor Secure Communities involve information sharing between federal and state law enforcement agencies to identify removable noncitizens who are arrested by state and local police.

Section 287(g) Agreements

Section 287(g) of the INA authorizes DHS to enter into agreements with state and local law enforcement agencies to delegate immigration enforcement authority to trained officers. Under these agreements, state and local officers may perform immigration officer functions, including the service of warrants, the arrest of removable noncitizens, and the preparation of charging documents.

287(g) agreements have been controversial, with critics arguing that they undermine trust between immigrant communities and local police. The use of 287(g) agreements has fluctuated across administrations, with some jurisdictions entering into agreements and others declining to participate.

Sanctuary Cities

Sanctuary cities are jurisdictions that limit their cooperation with federal immigration enforcement. Sanctuary policies take various forms, including prohibitions on inquiring about immigration status, restrictions on honoring ICE detainer requests, and limitations on the use of local resources for immigration enforcement.

The legal authority of states and localities to adopt sanctuary policies has been contested. In City of Chicago v. Sessions (2018), the Seventh Circuit held that the Attorney General lacked authority to impose conditions on Byrne JAG grants that required cooperation with immigration enforcement. In United States v. California (2019), courts upheld California’s sanctuary laws against constitutional challenges.

ICE Detainers

An ICE detainer is a request that a state or local law enforcement agency hold a person for up to 48 hours after their release from custody to permit ICE to assume custody. Detainer requests are voluntary, and many jurisdictions limit compliance to situations where the person has been convicted of a serious crime.

The legal status of detainers raises constitutional questions under the Fourth Amendment and the Tenth Amendment. Courts have held that detaining a person solely based on an ICE detainer, without probable cause, violates the Fourth Amendment.

Detention and Alternatives

ICE operates the largest immigration detention system in the world, with an average daily population of approximately 30,000 detainees. Detention is used for persons in removal proceedings, particularly those subject to mandatory detention. ICE also operates alternatives to detention programs, including GPS monitoring, telephonic reporting, and case management.

Conclusion

Immigration enforcement is a complex and politically controversial area of law. The division of authority between CBP and ICE, the role of state and local law enforcement, and the legal framework for detention define the enforcement landscape. The tension between enforcement priorities and due process protections continues to shape immigration enforcement policy and litigation.