What specific sections of the Immigration and Nationality Act authorize ICE warrantless arrests, and how have courts interpreted them?

1. The statutory text that ICE points to: 8 U.S.C. § 1357

Congress gave immigration officers express warrantless powers in 8 U.S.C. § 1357, including authority “without warrant” to interrogate any person believed to be an alien and to arrest an alien who is in the United States if the officer “has reason to believe” that the person is present unlawfully or likely to escape before a warrant can be obtained, and to execute administrative orders and warrants issued under immigration law ^[1].

2. How courts translate “reason to believe”: probable cause under the Fourth Amendment

Federal courts, and treatises relied on by Congress’s research service, have interpreted the statute’s “reason to believe” language to be equivalent to the Fourth Amendment probable-cause standard; under that construction, an immigration officer must have sufficient, articulable facts that would lead a reasonable person to conclude the individual violated immigration law and poses an escape risk before making a warrantless arrest ^{[2] [3] [6]}.

3. Limits when ICE acts in private spaces: judicial warrants and recent rulings

Although §1357 authorizes certain warrantless interior arrests, the breadth of that authority is constrained when enforcement intrudes into homes and other private spaces; courts have long held that the Fourth Amendment generally bars warrantless entries into a residence, and recent district rulings have found that agents violated the Constitution when entering homes without a judge-signed warrant—even as ICE has asserted administrative warrants suffice—creating active litigation over that boundary ^{[7] [4] [5]}.

4. Administrative warrants vs. judicial warrants: agency posture and legal pushback

ICE routinely uses administrative warrants (internal agency documents like Form I‑205) to authorize arrests; those documents are not signed by independent magistrates and traditionally have not been understood to authorize forcible home entry, but a 2025 ICE memo asserted such administrative warrants could be used for residential arrests, prompting legal challenges and criticism from civil liberties scholars who say that conflicts with established Fourth Amendment doctrine ^{[5] [7] [8]}.

5. Implementation rules, documentation, and procedural constraints

DHS/ICE guidance and settlement agreements require officers who make warrantless arrests under §1357(a) to document particularized facts—such as the specific circumstances supporting an officer’s belief that the person would escape before a warrant could be obtained—and ICE policy historically limited arrests at “sensitive locations” absent exigent circumstances ^{[9] [2]}.

6. Diverging judicial outcomes and areas of dispute

Courts have not been monolithic: some have upheld warrantless interior arrests where probable cause and exigency were properly documented, while others—especially in cases involving residential entry—have rejected agency arguments that administrative warrants alone permit forced home entry; federal judges have issued local limits (for example in D.C.) reiterating that warrantless arrests require probable cause that the person is unlawfully present and an escape risk ^{[10] [4] [11]}.

7. Competing narratives and what remains unsettled

ICE and DHS maintain statutory and regulatory bases for warrantless arrests under 8 U.S.C. § 1357 and for using administrative warrants in many circumstances, a position reflected in recent internal memos ^{[8] [1]}. Civil liberties groups, some federal judges, and legal commentators argue that constitutional limits mean administrative warrants cannot, by themselves, justify forcible home entry and that courts should enforce the probable-cause/exigency standard strictly; the tension between agency policy and constitutional doctrine is currently playing out in litigation ^{[7] [4] [10]}.