What statutory language in INA §1357 has courts interpreted when assessing ICE’s warrantless arrest authority?

1. The core arrest clause courts read: “reason to believe” and flight risk

The linchpin of judicial interpretation is § 1357(a), which permits a warrantless arrest of “any alien in the United States, if he has reason to believe that the alien so arrested is in the United States in violation of any such law or regulation and is likely to escape before a warrant can be obtained for his arrest,” a dual textual requirement that courts have equated with the Fourth Amendment’s probable-cause standard and that also requires an assessment—express or implicit—of escape risk before relying on the warrantless route ^{[2] [3] [4]}.

2. Presence, duties, and scope: when an officer may rely on § 1357

Section 1357(a) begins by tying the power “without warrant” to “Any officer or employee of the Service authorized under regulations prescribed by the Attorney General,” and further cases and Department of Justice guidance emphasize that the officer must be “performing duties relating to the enforcement of the immigration laws” when exercising arrest authority, a contextual limitation courts and executive manuals use to cabin interior arrest power ^{[1] [2] [5]}.

3. Criminal-offense subsections and their narrower triggers

Beyond (a)’s civil-removal context, § 1357(a)– and related text authorize warrantless arrests for certain criminal offenses when the offense is committed in the officer’s presence or where the officer has reason to believe a felony has been committed and the suspect is likely to escape—language courts have interpreted as requiring the same probable-cause-level “reason to believe” and the same escape risk analysis before a warrantless arrest is lawful ^{[2] [6]}.

4. Constitutional overlay: Fourth Amendment constraints that courts apply

Although the statute grants “power without warrant,” courts have repeatedly read § 1357 through the Fourth Amendment lens; the “reason to believe” standard has been understood by multiple courts as equivalent to probable cause, and courts will invalidate actions that lack individualized probable cause or where the escape justification is treated as perfunctory rather than substantive ^{[3] [4] [5]}.

5. Operational limits, regulations, and special statutory restrictions

Congress and the Attorney General’s regulatory structure impose further limits—§ 1357 ties authority to officers “authorized under regulations prescribed by the Attorney General,” and other statutory text and administrative policies (and even settlement agreements) require documentation, flight-risk analyses, and bar certain warrantless entries (for example, farm-entry restrictions enacted in later amendments), showing courts consider not only the statute’s arrest language but also regulatory and statutory constraints on when and how arrest powers are used ^{[1] [7] [8] [9]}.

6. Interplay with state and local arrests, and contested boundaries

Judicial rulings and state opinions reveal a complex boundary between federal arrest authority and state/local actions: some courts and state opinions have upheld state and local officers’ ability to arrest for federal criminal immigration offenses under state law frameworks, while other decisions underline that § 1357’s warrantless civil-arrest provisions do not automatically authorize state-only civil removals and that coordination under § 1357(g) or other mechanisms is often necessary—an area where statutory text meets preemption, cooperation agreements, and divergent judicial readings ^{[10] [3] [11]}.

7. How courts use the statute in practice—and open questions

In practice courts focus on the statutory tripwire: whether the officer is authorized and acting in enforcement duties, whether there is “reason to believe” (probable cause) the person is removable or committed a qualifying crime, and whether the “likely to escape” condition is met and documented; settlement terms and agency manuals underscore that failures in any of these statutory predicates have produced litigation and corrective orders, but the sources do not resolve every close question about how granular an individualized escape analysis must be in every context ^{[9] [8] [4]}.