The Supreme Court's Fourth Amendment decisions this year produced mixed results: a unanimous win in Barnes v. Felix expanded judicial review of police use of force by rejecting a narrow "moment of threat" test, while an unsigned September emergency order in Noem v. Perdomo allowed contested immigration enforcement tactics to resume. The September order drew a 3‑justice dissent and a concurrence from Justice Kavanaugh defending stops that consider "apparent ethnicity." Reports that U.S. citizens were detained despite showing ID have intensified concerns about profiling and overreach. Civil‑liberties advocates will be watching how lower courts and the Supreme Court refine these limits going forward.
Uneven Year For The Fourth Amendment At The Supreme Court: Landmark Win And A Troubling Order
The Fourth Amendment's Erratic Year at the Supreme Court
The Supreme Court's Fourth Amendment docket produced sharply divergent outcomes this year: a unanimous decision that broadened judicial review of police use of force, followed by an emergency order that alarmed civil‑liberties advocates by allowing contested immigration enforcement tactics to resume.
Barnes v. Felix — A Clear Victory For Broader Fourth Amendment Review
In May, the Court issued a unanimous 9–0 opinion in Barnes v. Felix. Writing for the Court, Justice Elena Kagan rejected a restrictive "moment of threat" rule that told judges to assess an officer's use of force by looking only at the instant the officer perceived danger.
"To assess whether an officer acted reasonably in using force, a court must consider all the relevant circumstances, including facts and events leading up to the climactic moment," Kagan wrote, criticizing the prior test as improperly narrow.
By requiring courts to examine antecedent events — including whether an officer's own tactics contributed to the escalation — the ruling strengthens the Fourth Amendment inquiry into whether force was reasonable under the circumstances. Civil‑liberties advocates hailed the decision as a meaningful expansion of constitutional safeguards.
Noem v. Perdomo — An Emergency Order That Raised Alarm
In stark contrast, in September the Court lifted a lower‑court injunction in Noem v. Perdomo that had blocked certain Trump administration immigration enforcement tactics. The Ninth Circuit had found those tactics likely violated the Fourth Amendment because agents appeared to detain people based on such unlawful criteria as "apparent race or ethnicity" or speaking Spanish or English with an accent.
The Supreme Court's action came as an unsigned emergency order allowing the enforcement actions to resume; Justices Kagan, Sonia Sotomayor and Ketanji Brown Jackson dissented from that order.
Only one justice who supported the order—Justice Brett Kavanaugh—explained his reasoning in a concurrence. He argued that officers may consider "relevant factors" such as "apparent ethnicity" or the fact that people "gather in certain locations to seek daily work," and minimized the practical impact on citizens, suggesting questioning is "typically brief" and that lawful residents "may promptly go free."
Justice Kavanaugh: "As for stops of those individuals who are legally in the country, the questioning in those circumstances is typically brief..."
But reporting from outlets such as Reason undermines that characterization: Autumn Billings wrote about George Retes, an Iraq War veteran who alleges he was detained for three days despite saying he was a U.S. citizen and identifying where his ID was; C.J. Ciaramella reported on Leo Garcia, a construction worker who says he was detained twice during warrantless raids despite carrying valid identification.
Why These Rulings Matter
The contrasting decisions show how the Court can simultaneously expand and constrict Fourth Amendment protections. Barnes v. Felix strengthens courts' ability to evaluate the reasonableness of force by looking beyond the split‑second moment; Noem v. Perdomo nevertheless signals tolerance — at least for now — of aggressive immigration stops that critics say risk racial or linguistic profiling.
What To Watch Next
Expect litigation and lower‑court rulings to continue testing the boundaries set by these decisions. Advocates and scholars will watch whether future opinions clarify the permissible scope of immigration stops and how courts apply the broader Fourth Amendment framework endorsed in Barnes.
As the new term approaches, civil‑liberties defenders hope the Court will trend toward stronger, more consistent protection against unreasonable searches and seizures.
