Geofence Warrants After Chatrie

Fourth Amendment Status of Geofence Warrants and Google Location History After Chatrie v. United States

The Supreme Court held that "[p]olice officers conducted a Fourth Amendment search when they acquired Chatrie’s location data from Google because an individual has a reasonable expectation of privacy in his cell-phone location information" Chatrie v. United States, 609 U.S. ___ (2026), decided June 29, 2026, vacating the Fourth Circuit’s en banc judgment and remanding. The Court refused to recognize any short-duration grace period for geofence data: "‘[E]ven short-term monitoring’ can provide ‘a wealth of detail about [a person’s] familial, political, professional, religious, and sexual associations,’" the Court explained, and it "has never understood Fourth Amendment protections as kicking in only once an intrusion ‘goes too far’" — "[w]here the Fourth Amendment applies, it applies regardless of ‘the quality or quantity of information’ the government obtains."

The holding builds directly on Carpenter v. United States, 585 U.S. 296 (2018), which held that "an individual maintains a legitimate expectation of privacy in the record of his physical movements as captured through CSLI" and that "the Government must generally obtain a warrant supported by probable cause before acquiring such records," because "[t]here is a world of difference between the limited types of personal information addressed in Smith and Miller and the exhaustive chronicle of location information casually collected by wireless carriers today." The Chatrie Court saw no basis to distinguish Google’s records: "Carpenter refused to apply the third-party doctrine to CSLI, and no good reason exists to reach a different result for Location History," which "is even more ‘revealing’ than CSLI and is ‘not truly shared’ in the normal sense of wanting a third party to see or use it." Accordingly, "a cell-phone user is not to be viewed as sharing private information with third parties—which then can be freely passed on to the government—just by doing the ordinary things cell-phone users do."

Chatrie resolves a split that had hardened in the courts of appeals. United States v. Smith, 110 F.4th 817 (5th Cir. 2024) held categorically that "geofence warrants are modern-day general warrants and are unconstitutional under the Fourth Amendment," reasoning that "the quintessential problem with these warrants is that they never include a specific user to be identified, only a temporal and geographic location where any given user may turn up post-search" — "the exact sort of ‘general, exploratory rummaging’ that the Fourth Amendment was designed to prevent." The en banc Fourth Circuit went the other way in United States v. Chatrie, 136 F.4th 100 (4th Cir. 2025) (en banc), affirming the denial of suppression solely on the good-faith exception without a majority on the search question; five judges would have held that "obtaining just two hours of location information that was voluntarily exposed is not a Fourth Amendment search and therefore doesn’t require a warrant at all" (Richardson, J., concurring) — the position the Supreme Court has now rejected.

With the search question settled, litigation shifts to the warrant requirements of U.S. Const. amend. IV: "no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized." The Supreme Court remanded Chatrie’s own particularity and probable-cause challenges to the Fourth Circuit, so the geofence-specific applications worked out below remain the operative guidance. United States v. Rhine, 652 F.Supp.3d 38 (D.D.C. 2023) upheld the January 6 Capitol geofence because "the fact of having entered the building during the geofence timeframe itself constitutes evidence of a crime," because "the relevant question is not how Google runs searches on its data, but what the warrant authorizes the Government to search and seize," and because "the terms of the initial warrant precluded disclosure of deanonymized device information except after separate order of the court based on a supplemental affidavit" — quoting the original Chatrie suppression ruling for the proposition that "where law enforcement establishes such narrow, particularized probable cause through a series of steps with a court’s authorization in between, a geofence warrant may be constitutional."

The good-faith exception remains the government’s backstop. The en banc Fourth Circuit declined suppression because "when law enforcement officials ‘act with an objectively reasonable good faith belief that their conduct is lawful,’" the "deterrence rationale loses much of its force, and exclusion cannot pay its way," and even the Fifth Circuit, after condemning geofence warrants categorically, admitted the evidence in United States v. Smith, 110 F.4th 817 (5th Cir. 2024) because "we cannot fault law enforcement’s actions considering the novelty of the technique and the dearth of court precedent to follow." After Chatrie, that novelty rationale has far less room to operate: acquiring Google Location History or geofence data is a Fourth Amendment search requiring a warrant regardless of the duration of data sought, the third-party doctrine supplies no exemption, and the validity of any particular geofence warrant turns on the particularity and probable-cause principles now to be developed on remand — with narrowly drawn geographic and temporal boundaries and court-supervised, step-by-step deanonymization as the features that have distinguished the warrants courts sustain from those they condemn.