*Philip Glaser
I. Introduction
Following the January 6, 2021 incursion on the U.S. Capitol, law enforcement faced a challenge: how could they identify the hundreds of people who entered the Capitol Building in violation of federal law?[1] To put names to faces, the FBI solicited tips,[2] scoured social media,[3] and enlisted assistance from Google.[4] In United States v. Rhine, the U.S. District Court for the District of Columbia reveals in detail how law enforcement pursued a “geofence” warrant, prompting Google to turn over the identities of account holders whose devices were present inside the Capitol in the critical hours of that afternoon.[5] The use of such warrants is not just limited to events of grand historical importance, however. In United States v. Chatrie, the Court of Appeals for the Fourth Circuit will provide the first federal appellate court guidance on the issue of geofence searches more generally, as it addresses whether a bank robbery suspect’s Google Location History should be suppressed on Fourth Amendment grounds.[6] The contrasting analyses of the geofence warrants in Chatrie and Rhine reveal an emerging federal jurisprudence of intense scrutiny that may deter these searches for all but the most extraordinary of circumstances.
II. The Warrant Requirement and Its Exceptions
The Fourth Amendment protects the people “against unreasonable searches and seizures.”[7] However, it does permit such intrusions if they are executed under a warrant based on probable cause “particularly describing the place to be searched, and the person or things to be seized.”[8] To deter infractions of the warrant requirement, the Supreme Court applies the exclusionary rule, which bars the government from using evidence at trial that was seized through a defective warrant.[9] Acknowledging that there are occasions in which the exclusionary rule does not actually serve as a deterrent, the Court also recognizes a good-faith exception: when an officer reasonably relies on a defective warrant, evidence seized under its authority may still be used at trial.[10] By another exception, the third party doctrine, the Court relieves the government of the warrant requirement in instances where the government seeks information from a third party, reasoning that by sharing the sought information with the third party, the defendant can have no legitimate expectation of privacy.[11] As increasingly invasive investigatory methods emerge, enabled by ever-growing amounts of collected user data, the Supreme Court relies on a traditional framework to uphold the Fourth Amendment while recognizing modern manifestations of doctrinal exceptions.[12]
III. The “quagmire of geofence search warrants”[13]
- Chatrie Illustrates Fourth Amendment Limits on Geofence Searches
With no federal appellate authority on the matter,[14] the trial judge in Chatrie endeavored to apply Fourth Amendment doctrine to the “previously unimaginable investigatory method” of the geofence search.[15] There, the suspect robbed a bank of $195,000 during business hours.[16] With no leads on the suspect’s identity, law enforcement leveraged the suspect’s observed cell phone use to get a geofence warrant.[17] The warrant compelled Google to reveal location information of all users within a 150-meter radius of the bank in an hour window around the time of the robbery.[18] The trial judge determined that the search warrant was deficient, citing the Fourth Circuit’s rule that warrants “that authorize the search of every person within a particular area must establish probable cause to search every one of those persons.”[19]
Though the broad search did capture the location history of the robbery suspect, it also included others for whom there was no probable cause to search.[20] The court also highlighted that law enforcement improperly sidestepped judicial discretion by failing to follow the multistep process of narrowing down suspect Google accounts described in the warrant.[21] Nevertheless, because the officer who procured the warrant reasonably relied on prior similar warrants, the prosecutor, and the magistrate, the court allowed the government to use the fruits of the defective geofence warrant under the good-faith exception.[22]
B. Rhine Exhibits a Geofence Warrant with Properly Implemented Restraints
In contrast with Chatrie, the trial judge in Rhine found that the January 6th Google geofence search satisfied the warrant requirement due to narrowing measures taken by the government.[23] The government only sought location history for users whose devices were within a geofence area drawn to closely match the interior footprint of the Capitol during the incursion.[24] To filter out devices belonging to those authorized to be in the Capitol, the government also requested control data from times before and after the event, when the building was known to be secure.[25] In addition, the government limited its request to location data points for which the entire error radius[26] fell within the geofence, further decreasing the chance of false positives.[27] The nature of the suspected crime—unauthorized presence—made any match to the above criteria itself evidence of a crime, strongly supporting probable cause for the search.[28] In the end, the government’s narrowing measures reduced a return of 5,723 devices down to 1,535.[29] The court also credited the government’s self-imposed prohibition on requesting deanonymized information from Google without an additional court order, another stark contrast with the process in Chatrie.[30]
V. Conclusion
In its review of the warrant in Chatrie, the Fourth Circuit will have an opportunity to weigh in on what makes a proper geofence warrant, likely taking notes from the Rhine decision. More importantly, however, it will be able to clarify whether individuals have a reasonable expectation of privacy in data obtained by such searches, a matter the trial judges in Rhine and Chatrie declined to decide.[31] Geofence searches represent “‘an almost unlimited pool from which to seek location data,’ such that ‘police need not even know in advance whether they want to follow a particular individual, or when.’”[32] As law enforcement leans more heavily on this unprecedented power, and the excuses for poorly planned and executed warrants afforded by the good-faith exception wear thin, the courts must return to the roots of the Fourth Amendment and extend its protections to the age of surveillance.
*Philip Glaser is a second-year student at the University of Baltimore School of Law and a staff editor for Law Review. He came to law school after a decade-long career in education. In the summer of 2023, Philip worked as a judicial intern for Hon. Brendan A. Hurson at the U.S. District Court for the District of Maryland. In the fall, he is serving as a Law Scholar for Professor Dolin’s Torts class. Philip intends to practice at the intersection of criminal defense and civil rights.
[1] Spencer S. Hsu, Justice Dept. Calls Jan. 6 ‘Capitol Attack’ Probe One of Largest in U.S. History, Expects at Least 400 to Be Charged, Wash. Post (Mar. 12, 2021, 7:28 PM), https://www.washingtonpost.com/local/legal-issues/capitol-attack-investigation-largest/2021/03/12/5c07b46c-833d-11eb-9ca6-54e187ee4939_story.html.
[2] Kevin Collier, Selfies, Social Media Posts Making it Easier for FBI to Track Down Capitol Riot Suspects, NBC News (Jan. 16, 2021, 6:34 PM), https://www.nbcnews.com/tech/social-media/selfies-social-media-posts-making-it-easier-fbi-track-down-n1254522.
[3] Id.
[4] Mark Harris, How a Secret Google Geofence Warrant Helped Catch the Capitol Riot Mob,Wired(Sep. 30, 2021, 7:00 AM),https://www.wired.com/story/capitol-riot-google-geofence-warrant/.
[5] United States v. Rhine, No. 21-0687, 2023 WL 372044, at *1 (D.D.C. Jan. 24, 2023).
[6] United States v. Chatrie, 590 F.Supp.3d 901 (E.D. Va. 2022), appeal docketed, No. 22-04489 (4th Cir. Aug. 29, 2022).
[7] U.S. Const. amend. IV.
[8] Id.
[9] Weeks v. United States, 232 U.S. 383, 398 (1914);Mapp v. Ohio, 367 U.S. 643, 655 (1961).
[10] United States v. Leon, 468 U.S. 897, 922 (1984).
[11] Smith v. Maryland, 442 U.S. 735, 744–46 (1979).
[12] See, e.g., Katz v. United States, 389 U.S. 347 (1967); United States v. Jones, 565 U.S. 400 (2012); Carpenter v. United States, 138 S. Ct. 2206 (2018).
[13] United States v. Rhine, No. 21-0687, 2023 WL 372044, at *22 (D.D.C. Jan. 24, 2023) (quoting United States v. Davis, No. 21-101, 2022 WL 3009240, at *9 (M.D. Ala. Jul. 1, 2022)).
[14] See United States v. Chatrie, 590 F.Supp.3d 901, 906 (E.D. Va. 2022), appeal docketed, No. 22-04489 (4th Cir. Aug. 29, 2022) (noting a “dearth of case law addressing geofence warrants”).
[15] Id. at 905.
[16] Id. at 917.
[17] Id.
[18] Id. at 917–19.
[19] Id. at 927.
[20] Id.
[21] Id. at 927, 934 n.44 (“Det. Hylton returned the warrant before it was served, improperly requested Step 2 and 3 information simultaneously, failed at first to narrow his request at Step 2, and incorrectly tried to add a Step 4 to the process.”)
[22] Id. at 937–38.
[23] United States v. Rhine, No. 21-0687, 2023 WL 372044, at *27 (D.D.C. Jan. 24, 2023).
[24] Id. at *18, *29.
[25] Id. at *29.
[26] See id. at *18 (explaining that a location data point’s error radius describes a circle containing the user’s actual location with 68% certainty).
[27] Id. at *30.
[28] Id. at *29.
[29] Id. at *30.
[30] Id. at *32.
[31] Id. at *28; United States v. Chatrie, 590 F.Supp.3d 901, 925 (E.D. Va. 2022), appeal docketed, No. 22-04489 (4th Cir. Aug. 29, 2022).
[32] Id. at *22 (quoting Leaders of a Beautiful Struggle v. Balt. Police Dep’t, 2 F.4th 330, 342 (4th Cir. 2021) (en banc).
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