United States v. Smith | Geofence Warrants & Fourth Amendment

Executive Summary

The Case in One Paragraph

Federal investigators used geofence warrants during an investigation into the armed robbery of a postal employee. Instead of identifying a known suspect and seeking that person's location records, investigators identified geographic areas surrounding relevant locations and required Google to search its Location History database for devices present within those boundaries during specified time periods. The multi-step process initially returned anonymous device information, which investigators narrowed before Google disclosed identifying account information. The Fifth Circuit concluded that this investigative method violated the Fourth Amendment. The court reasoned that a geofence warrant required Google to search location data associated with a vast universe of users before investigators knew whose information would prove relevant, creating the kind of exploratory search the Fourth Amendment's prohibition against general warrants was designed to prevent. Nevertheless, the court declined to suppress the evidence because officers had acted in objectively reasonable reliance on judicially issued warrants in an unsettled area of law.

Core Rule The Fifth Circuit held that the geofence warrants before it were unconstitutional because their reverse-search architecture functioned as general warrants, but suppression was unwarranted because investigators reasonably relied on judicial authorization before controlling law clearly prohibited the technique.

Key Holdings at a Glance

Geofence Warrants Were Searches Government-compelled access to stored Google location information implicated Fourth Amendment privacy interests.

Reverse Searching Was Central Investigators did not begin with an identified suspect. Google searched location records to determine who had been present in a defined place and time.

General-Warrant Concern Controlled The court viewed the compelled database-wide search as the modern analogue of exploratory rummaging prohibited by the Fourth Amendment.

Particularity Was Structurally Difficult Because investigators did not yet know the identities of the persons whose records would be searched, the warrant could not operate like a conventional suspect-focused warrant.

Good Faith Prevented Suppression The warrants had been approved by judges, and the constitutional status of geofence warrants was unsettled when investigators used them.

Circuit Conflict Emerged Smith expressly disagreed with the Fourth Circuit's treatment of geofence warrants in United States v. Chatrie.

The Postal-Robbery Investigation

The case arose from an armed robbery involving a United States Postal Service employee in Mississippi. Investigators lacked complete information identifying the persons responsible and sought digital location evidence that might reveal which devices had been present around relevant locations during the offense.

Rather than asking Google for records associated with an already identified suspect, investigators used geographic boundaries and time periods. Google was required to search stored Location History information to determine which devices fell within the requested areas.

The resulting data helped investigators identify persons associated with the robbery. Additional evidence ultimately led to prosecution and convictions.

Reverse Identification A conventional location warrant typically begins with a known person, device, or account and asks where that target was located. A geofence warrant reverses that sequence: investigators begin with the place and ask the provider to identify devices that were there.

How the Geofence Warrant Process Worked

Google's Location History system stored location information associated with users who had enabled the relevant account feature. The government sought records through a staged process designed to move from unidentified devices toward possible suspects.

Step One: Search the Geographic Boundary

Google searched stored location records to identify devices that fell within the geographic and temporal parameters contained in the warrant. Investigators initially received anonymized identifiers rather than subscriber names.

Step Two: Additional Location Information

Investigators could request additional information about selected anonymous devices in an effort to determine whether a particular device's movements were relevant to the investigation.

Step Three: Account Identification

After narrowing the list, investigators could request identifying subscriber information associated with selected devices.

The Structural Problem The Fifth Circuit focused not merely on what investigators ultimately received, but on what Google first had to search. To identify devices inside the geofence, the provider had to compare the warrant criteria against a far broader repository of users' stored location information.

The Fourth Amendment Search

The court treated compelled government access to the location information as implicating the Fourth Amendment. Modern cellphone-location data can disclose movements, associations, habits, destinations, and visits to constitutionally sensitive places.

That privacy concern closely relates to the Supreme Court's reasoning in Carpenter v. United States, which recognized that historical cellphone location records can reveal an extensive chronicle of a person's physical movements.

Geofence warrants add a distinct feature: the government does not know which person's location history it wants until after the provider performs the search.

Reverse-Search Concern The fact that investigators ultimately receive only a subset of records does not eliminate the constitutional concern created when the search process begins by examining location information associated with a much larger population of users.

Why the Fifth Circuit Viewed the Warrants as General Warrants

The Fourth Amendment was adopted against the historical abuse of general warrants and writs of assistance—authorizations that permitted officials to conduct broad exploratory searches without identifying the particular persons, places, or things properly subject to search.

The Fifth Circuit saw a similar structural problem in the geofence process. Investigators defined a place and time, but they did not know whose records Google would have to examine to identify potentially relevant devices.

The court reasoned that the required provider search was therefore not limited at its inception to a known suspect or identified account. Instead, the process began with a broad search through location information associated with users who had not been suspected of wrongdoing.

Major Holding Smith characterized the geofence warrants before the court as modern general warrants and held their use unconstitutional under the Fourth Amendment.

The Particularity Problem

The Fourth Amendment requires warrants to particularly describe the place to be searched and the persons or things to be seized. Particularity limits officer discretion and prevents exploratory searches.

Geofence warrants create an unusual particularity problem because investigators cannot identify the accounts or persons whose information will be searched before the provider performs the reverse-location query.

Geographic and temporal boundaries may narrow the search, but the Fifth Circuit concluded that those limits did not cure the basic structural problem in the warrants before it.

Traditional Versus Reverse Warrant A traditional warrant usually identifies the target first and then authorizes a search for specified evidence. A geofence warrant uses the search itself to identify the target. Smith viewed that inversion as constitutionally significant.

Smith, Carpenter, and Location Privacy

Carpenter v. United States held that individuals generally maintain a reasonable expectation of privacy in qualifying historical cellphone location information despite the records being maintained by a third-party provider.

Smith operates in the same constitutional environment but addresses a different investigative architecture. Carpenter involved acquisition of historical records associated with an identified person. Smith involved a provider searching stored location information to discover which users should become investigative targets.

The combination of location sensitivity and reverse identification heightened the Fifth Circuit's concern.

Doctrinal Distinction Do not treat Carpenter and Smith as interchangeable. Carpenter principally addresses privacy in historical location information. Smith additionally addresses the particularity and general-warrant problem created when the government uses location data to identify an unknown suspect.

Why the Good-Faith Exception Still Applied

Although the Fifth Circuit found the geofence warrants unconstitutional, it did not suppress the resulting evidence.

Investigators had sought warrants from judges rather than accessing the information without judicial authorization. At the time, the constitutional status of geofence warrants was unsettled, and courts had not clearly established that this form of process was forbidden.

Under United States v. Leon, suppression ordinarily does not serve the exclusionary rule's deterrent purpose when officers objectively and reasonably rely on judicial authorization in an unsettled area of law.

Remedial Holding Smith invalidated the investigative process but preserved the evidence because the officers' reliance on the judicially approved warrants was objectively reasonable under the law existing at the time.

Future Reliance A good-faith ruling is time-sensitive. Once controlling precedent declares a technique unconstitutional, continued reliance on older practices becomes substantially harder to characterize as objectively reasonable.

What Smith Does—and Does Not—Establish

Smith is binding federal authority within the Fifth Circuit.
It does not automatically control agencies in other federal circuits.
The decision addresses the geofence process described in the case rather than every conceivable form of reverse-location investigation.
The court's constitutional holding and its suppression ruling are different. The search was unconstitutional, but the evidence was admitted through good faith.
Smith does not hold that all location warrants are unconstitutional. It focuses on reverse identification through provider-wide searching.
The ruling does not prevent investigators from using traditional warrants directed at identified accounts or devices when supported by probable cause and sufficient particularity.
State constitutions and statutes may impose greater restrictions even outside the Fifth Circuit.
Later Supreme Court authority may alter how Smith's reasoning should be applied.

Smith Compared with Major Geofence Decisions

Case	Approach	Central Rule
United States v. Smith	Fifth Circuit	Geofence warrants as described were unconstitutional general warrants; good faith prevented suppression.
United States v. Chatrie	Fourth Circuit / later Supreme Court review	Major federal geofence litigation concerning location privacy and reverse-location warrants.
People v. Meza	California Court of Appeal	Geofence warrant found overbroad and insufficiently particular; evidence nevertheless survived under good faith.
Price v. Superior Court	California Court of Appeal	More narrowly constructed geofence warrant upheld on the facts presented.
Carpenter v. United States	U.S. Supreme Court	Qualifying historical cellphone location information receives Fourth Amendment protection.
United States v. Leon	U.S. Supreme Court	Objectively reasonable reliance on a judicial warrant can prevent suppression despite a constitutional defect.

Agency Operations Checklist

Identify whether the investigation is target-first or location-first. Reverse identification creates constitutional issues distinct from conventional warrants for known accounts.
Describe exactly what the provider must search. Do not focus only on the records ultimately returned to investigators.
Define the smallest defensible geography. Tie boundaries to the offense location and investigative facts.
Use the shortest defensible time period. Avoid broad windows unsupported by the known timing of the offense.
Explain expected innocent-user exposure. Consider residences, businesses, roadways, churches, medical facilities, schools, and high-traffic areas within the boundary.
Provide probable cause for the reverse-search methodology. Explain why the perpetrator likely possessed a relevant device and why the requested provider records are likely to identify evidence.
Address controlling case law directly. Warrant applications should acknowledge material precedent rather than assuming geofence process is constitutionally routine.
Consult prosecutors or agency counsel. Reverse-location investigations remain legally sensitive and jurisdiction-dependent.
Preserve every stage of provider disclosure. Maintain anonymous identifiers, narrowing decisions, supplemental requests, subscriber disclosures, and investigator notes.
Build independent corroboration. Do not treat presence inside a geofence as proof that the device owner committed the offense.

Litigation and Review Checklist

Determine the exact geographic boundary and time period authorized.
Identify how many user accounts or devices were searched at the provider level.
Identify how many anonymous devices were initially disclosed.
Document the criteria investigators used to narrow the device list.
Determine whether additional historical movements were disclosed during later stages.
Identify when subscriber information was first revealed.
Analyze probable cause separately from particularity.
Evaluate whether the warrant required exploratory searching of information belonging to unidentified nonsuspects.
Compare the process to current controlling circuit and Supreme Court precedent.
Analyze good faith separately from the underlying constitutional violation.
Determine whether later evidence rested independently on surveillance, interviews, conventional warrants, or other sources.

Frequently Asked Questions

What is a geofence warrant?

A geofence warrant requires a provider to identify devices located within a defined geographic area during a defined time period, even though investigators do not initially know the identities of the device users.

Did Smith hold geofence warrants unconstitutional?

Yes. The Fifth Circuit held that the geofence warrants before it violated the Fourth Amendment and characterized their reverse-search structure as a form of prohibited general warrant.

Was the evidence suppressed?

No. The court applied the good-faith exception because investigators had obtained judicial warrants in an unsettled area of constitutional law.

Why did the court consider the warrants “general”?

Because the process required Google to search a much broader universe of users' stored location information before investigators knew which accounts were connected to the offense.

Does Smith apply nationwide?

It is binding federal appellate authority within the Fifth Circuit. Other jurisdictions must follow their own controlling authority, although Smith remains significant persuasive authority elsewhere.

Does Smith prohibit ordinary warrants for cellphone location records?

No. The central issue was the reverse-identification architecture of geofence warrants, not conventional warrants directed at a known person, device, or account.

Can geographic and temporal limits cure every geofence warrant?

Not under Smith's reasoning. Although narrow boundaries reduce intrusiveness, the Fifth Circuit concluded that the deeper constitutional problem was the requirement that the provider search records belonging to unidentified users in order to discover the target.

Why does Leon matter?

Leon explains why evidence may remain admissible when officers reasonably relied on a judge's warrant before the constitutional defect was clearly established.

Primary Authorities and Related Law

United States v. Smith, 110 F.4th 817 (5th Cir. 2024)
Published Fifth Circuit decision holding the geofence warrants at issue unconstitutional while applying the good-faith exception.
Read United States v. Smith

Carpenter v. United States, 585 U.S. 296 (2018)
Supreme Court decision recognizing Fourth Amendment protection for qualifying historical cellphone location information.
Read Carpenter v. United States

United States v. Leon, 468 U.S. 897 (1984)
Supreme Court decision establishing the good-faith exception for objectively reasonable reliance on a judicial warrant.
Read United States v. Leon

United States v. Chatrie
Major federal geofence-warrant litigation addressing reverse-location identification and cellphone location privacy.
Read the Fourth Circuit decision

Final Assessment

United States v. Smith is one of the strongest appellate warnings against reverse-location warrants. The Fifth Circuit's concern was not simply that cellphone location information is sensitive. It was that the investigative process required a provider to search across a broad population of users before the government knew whose information it had probable cause to seek.

That structure led the court back to one of the Fourth Amendment's oldest principles: government searches should be particularized rather than exploratory. A geographic boundary and time limit may reduce the number of people affected, but Smith concluded that the reverse-identification architecture still resembled the general warrants the Fourth Amendment was designed to eliminate.

The decision's good-faith ruling is equally important. Officers sought judicial authorization at a time when courts were still developing the governing rules. Suppression therefore was not warranted. But that remedial conclusion should not be confused with approval of the investigative technique itself.

Shield Practice Rule Treat reverse-location warrants as a distinct and high-risk form of digital search. Analyze not only what records investigators ultimately receive, but whose data the provider must search to identify the target; use the narrowest defensible geography and time period; address controlling precedent directly; and never assume judicial approval alone resolves the general-warrant problem.