United States v. Thorne
The D.C. Circuit decision applying good faith to a cell-site-simulator warrant challenged under Rule 41(b)’s territorial venue limits.
Executive Summary
After searching Linwood Thorne’s suspected D.C. residence and Maryland business, officers obtained an arrest warrant and sought to locate him through two associated cellphones. A D.C. magistrate judge issued GPS-ping and cell-site-simulator warrants for both numbers. Provider ping data placed Thorne’s 202-area-code phone in Baltimore, and a simulator deployed in Maryland pinpointed it at an apartment where officers arrested him. Thorne argued that the simulator warrant violated Federal Rule of Criminal Procedure 41(b) because the affidavit did not establish that the phone was within the District of Columbia when the D.C. judge issued the warrant. The D.C. Circuit affirmed denial of suppression without deciding what level of certainty Rule 41(b) requires or whether the warrant was valid. It held that the officers reasonably relied on the judicial warrant, adequately presented the venue issue, and engaged in no deliberate, reckless, or grossly negligent conduct. The opinion suggested—but expressly did not decide—that probable cause may be the proper Rule 41(b) standard and explained that probable cause can exist simultaneously in more than one adjoining district.
Key Holdings at a Glance
Interstate Drug and Firearms Investigation
In 2018, the FBI, ATF, and Metropolitan Police Department investigated Omar Elbakkoush for drug and firearms trafficking across D.C., Maryland, and Virginia. Controlled purchases led agents to suspect Thorne was Elbakkoush’s heroin supplier.
Surveillance indicated that Thorne likely lived with his girlfriend at a Foote Street home in northeast D.C. and owned an auto body shop, Dou’ Perfect, in Clinton, Maryland. Search warrants executed at both locations produced large quantities of marijuana, heroin, fentanyl, firearms, drug equipment, and documents associated with Thorne.
After Thorne was indicted and an arrest warrant issued, officers attempted to locate him. Negotiations for voluntary surrender through attorneys did not succeed, so the Marshals Service, ATF, and FBI turned to his cellular devices.
The Maryland and D.C. Phone Numbers
Agents associated two numbers with Thorne. A 301-area-code number was tied to his Maryland auto body shop and confirmed by his girlfriend. A 202-area-code number came to investigators through an attorney attempting to arrange Thorne’s surrender.
Officers applied for a GPS-ping warrant and a cell-site-simulator warrant for each number. The Maryland-area-code phone was turned off and did not produce useful location results. The 202 number remained active.
GPS Pings and Cell-Site-Simulator Precision
The opinion carefully distinguished the two methods. A GPS-ping warrant directs the carrier to cause the phone to report coordinates and transmit the result to law enforcement. In the court’s description, pinging provided a location within roughly 500 to 1,000 meters.
A cell-site simulator mimics a tower, induces nearby devices to connect, receives identifying and directional information, and can be focused on the target phone. Continuous signal-strength and direction analysis can come close to the device’s exact location.
Ping results placed Thorne’s 202 phone in Baltimore. Officers then deployed the simulator in Maryland and pinpointed the phone at a Linden Avenue apartment, where they arrested him.
| Method | Operator | Function in Thorne |
|---|---|---|
| GPS ping | Carrier acting under warrant | Placed phone in a broader Baltimore area |
| Cell-site simulator | Law enforcement equipment | Pinpointed the target apartment |
| Arrest warrant | Executing officers | Authorized Thorne’s apprehension |
| Phone-content warrant | Later forensic search | Authorized review of seized phone contents |
Rule 41(b)’s Territorial Limits
Rule 41(b)(1) generally authorizes a magistrate judge to issue a warrant for a person or property located within the district. Rule 41(b)(2) also permits a warrant for property that is within the district when issued but may move outside the district before execution.
The D.C. application stated there was reason to believe the target phone was currently somewhere in the District because Thorne lived at the Foote Street address and continued using the device. It expressly invoked Rule 41(b)(2) for later location outside D.C.
Thorne argued that the judge needed probable cause—not merely reason to believe—that the phone was inside D.C. at issuance. Because evidence also connected him to Maryland, he maintained that the D.C. judge lacked territorial authority and the warrant was void from the outset.
The District Court’s Reason-to-Believe Standard
The district court treated the Rule 41(b) issue as one of first impression and held that a “reason to believe” standard governed whether the phone was located within D.C. It found that Thorne’s D.C. residence and the phone’s 202 area code supplied that basis.
The district court rejected a probable-cause standard in part because evidence pointed toward both D.C. and Maryland. It feared that requiring probable cause would make a warrant unavailable in either jurisdiction when officers were trying to discover the phone’s location.
It also ruled alternatively that good faith would defeat suppression even if the warrant violated Rule 41(b). The D.C. Circuit affirmed solely on that alternative ground.
Why the Good-Faith Exception Applied
Under United States v. Leon, exclusion ordinarily does not deter police misconduct when officers objectively and reasonably rely on a warrant issued by a neutral judge.
The investigators did not conceal the venue problem. Their affidavit cited Rule 41(b)(2), stated why they believed the phone might be in D.C., explained Thorne’s D.C. residence, and noted his continued use of the device. The magistrate judge implicitly resolved her authority by issuing the warrant.
The appellate court found no deliberate, reckless, or grossly negligent conduct. The proper degree of certainty was novel and unsettled, and officers were entitled to submit that legal question to the magistrate judge. Any error was attributable to the issuing court, so suppression would add little deterrence.
Probable Cause Can Exist in More Than One District
Although it reserved the governing Rule 41(b) standard, the panel criticized part of the district court’s reasoning. Probable cause requires only a fair probability, is not a high bar, and demands less than 50-percent certainty.
Thus, the evidence could establish probable cause that the phone was in D.C. because Thorne resided there and also probable cause that it was in Maryland because he operated a business there. Those conclusions are not mathematically or legally inconsistent.
The court suggested there may be good reason to use the familiar, practical probable-cause standard for Rule 41(b), but explicitly left the question for another case.
Why the Warrant Was Not Facially Void
Thorne argued that a jurisdictionally defective warrant is void from the beginning and cannot support good faith. The court rejected that categorical argument.
Unlike warrants that openly targeted a fixed object or premises known to be outside the issuing district, this warrant concerned a mobile phone whose location was uncertain. The application offered facts supporting D.C. location and did not reveal an obvious territorial contradiction on its face.
Rule 41(b) also lacks the statutory suppression command found in some communications laws. The court held that good faith can apply to an alleged Rule 41(b) violation and joined the approach of other federal circuits.
The Court Did Not Decide Whether Simulator Use Is a Search
The government noted that the Fourth Amendment status of simulator use remained open in the circuit but did not argue that no warrant was required. The appellate court therefore did not decide the issue.
The case proceeded on an issued probable-cause simulator warrant. Its holding concerns venue and remedy—not whether investigators could have used the technique without judicial authorization.
Judge Rogers’s Separate Opinion
Senior Judge Rogers joined the holding that the good-faith exception required affirmance. She declined to join the panel’s additional discussion of the unresolved Rule 41(b) standard.
Her separate opinion reinforces the limited nature of the binding result: good faith disposed of the appeal, and extended commentary about venue probability was unnecessary to judgment.
Current Significance
Thorne is a current appellate reminder that sophisticated warrants have both substantive and territorial requirements. Probable cause connecting a suspect to a phone does not automatically establish which judge has authority to issue the warrant.
Investigations in metropolitan border areas must account for ordinary movement among districts. Agencies should consider parallel or coordinated applications, appropriate federal statutory authority, mobile-property provisions, and early consultation with prosecutors.
The opinion also confirms the importance of separating GPS-ping process, simulator authority, arrest authority, premises entry, seizure, and phone-content searches. Thorne’s investigators obtained distinct warrants for those stages.
Practical Guidance for Agencies
Territorial Simulator Warrant Checklist
- Identify the offense, target, phone, provider, and all known device identifiers.
- Establish probable cause connecting the target to the device and investigative objective.
- State the issuing court’s territorial authority and governing provision.
- Provide current facts supporting the phone’s location when the warrant issues.
- Explain expected movement and authority for execution outside the district.
- Separate provider pinging from direct simulator operation.
- Define precision, duration, geography, deployment settings, and stopping events.
- Address homes, non-target devices, content limits, minimization, and deletion.
- Require logs and a return identifying where and how execution occurred.
- Seek renewed or parallel authority when material territorial facts change.
Cross-Border Operations Checklist
- Confirm issuance time, target identifiers, territorial basis, and expiration.
- Record the phone’s best-known location at the moment of issuance.
- Separate carrier ping results from simulator-derived information.
- Document each district entered and the legal basis for continued execution.
- Coordinate local agencies, prosecutors, supervisors, and technical operators.
- Pause before premises entry and confirm separate authority.
- Stop when the target is found, objective achieved, or authority ends.
- Preserve configuration, location, timing, readings, and operational decisions.
- Report deviations and obtain supplemental authority when required.
- Complete judicial returns, discovery, audit, and after-action review.
Litigation and Discovery Checklist
- Obtain every ping warrant, simulator warrant, affidavit, return, and arrest warrant.
- Build a time-and-location chronology from issuance through execution.
- Identify the precise territorial rule, statutory authority, and issuing judge’s jurisdiction.
- Test facts supporting device location at issuance—not only later ping results.
- Separate probable cause for the crime from probable cause or belief about venue.
- Determine whether the warrant was facially defective or presented an unsettled legal issue.
- Analyze the merits of any Rule 41 violation separately from good faith and prejudice.
- Distinguish binding holding from the panel’s reserved-standard discussion.
- Review protected-place entry, seizures, and later content warrants separately.
- Apply any superseding rule amendments and current circuit authority.
Frequently Asked Questions
What did United States v. Thorne hold?
The D.C. Circuit held that suppression was unwarranted because officers relied in good faith on a judicially issued cell-site-simulator warrant.
What was wrong with the warrant according to Thorne?
He argued that the D.C. magistrate lacked Rule 41(b) authority because the affidavit did not adequately establish that his phone was inside D.C. when the warrant issued.
Where was the phone ultimately located?
Provider pinging placed it in Baltimore, and a simulator pinpointed it at a Linden Avenue apartment.
Did the court decide the warrant was valid?
No. It assumed a possible Rule 41(b) error and resolved the appeal through good faith.
Did the court require probable cause for territorial location?
No definitive holding was issued. The panel suggested probable cause may be appropriate but reserved the question.
Can probable cause point to two districts?
Yes. The court explained that a fair probability can exist in more than one location because probable cause requires less than 50-percent certainty.
Did Thorne hold simulator use is not a search?
No. The government did not rely on that argument, and the court did not reach it.
Why did Judge Rogers write separately?
She agreed that good faith controlled but did not join the majority’s additional discussion of the unresolved Rule 41(b) standard.
Primary Authorities and Current Law
D.C. Circuit opinion affirming through good faith while reserving the Rule 41(b) standard.
Read United States v. Thorne
District-court opinion finding Rule 41 compliance and alternatively applying good faith.
Read the district-court decision
Federal warrant rule governing territorial authority and specified categories of searches.
Read Rule 41
Supreme Court decision establishing the objective good-faith exception.
Read United States v. Leon
D.C. Circuit decision applying good faith to an analogous alleged jurisdictional defect in cellular-location process.
Read United States v. Magruder
Final Assessment
United States v. Thorne is a good-faith decision with a forward-looking venue lesson. Investigators did many things correctly: they obtained simulator-specific warrants, identified the territorial issue, supplied current facts, and sought judicial resolution rather than acting unilaterally.
The opinion nevertheless leaves the governing Rule 41(b) standard open. Its observation that probable cause may exist simultaneously in D.C. and Maryland provides useful drafting guidance for mobile targets in adjoining jurisdictions, but it is not a definitive holding on the standard.