No Unsupported Facts: Seventh Circuit Clarifies Standing, Government Proof Duties, and the Scope of Supervised‑Release Searches in United States v. Dixon

Introduction

In United States v. Marcus T. Dixon, No. 23-2427 (7th Cir. May 7, 2025), the Seventh Circuit affirmed the denial of a motion to suppress evidence obtained during a succession of warrantless searches executed by probation officers under a supervised-release search condition. The decision, authored by Judge Hamilton and joined by Judges Easterbrook and Maldonado, addresses three interlocking issues:

Fourth Amendment “standing” and the defendant’s burden to establish a personal, legitimate expectation of privacy in places and things searched;
The impropriety of district courts relying on unsupported attorney factual assertions in resolving suppression motions, and the related allocation of proof when the government justifies warrantless searches; and
The scope and triggering standards for supervised‑release search conditions, including how certain officers must be that the property searched is the supervisee’s, and whether “and/or” language requires reasonable suspicion of a violation, evidence, both, or either.

Although the panel criticized a local practice (reported at oral argument) of resolving suppression motions on unsupported factual statements, it ultimately affirmed. The outcome turned on Dixon’s failure to prove standing and, alternatively, the reasonableness of the searches of the Pontiac and cellphone under his search condition, based on trial evidence the appellate court permissibly considered.

Summary of the Opinion

Standing: The defendant bears the burden to show a legitimate expectation of privacy in the areas searched. Dixon offered no affidavit, testimony, or record evidence to establish such an interest in the Pontiac, cellphone, Silvis residence, Audi, or duffel bag. He could not rely on the government’s litigation positions to fill that gap. Result: no standing to challenge any of the December 18 searches.
District court’s reliance on unsupported facts: The district court erred by relying on the government’s unsupported factual assertions (e.g., supposed disclaimers by Dixon). Unsupported attorney assertions are not evidence. The error was harmless because Dixon independently failed to prove standing.
Reasonableness (alternative ground): Using trial evidence (consistent with Seventh Circuit precedent allowing appellate consideration of trial records), the court held the Pontiac and cellphone searches were reasonable. The supervised‑release condition authorized searches upon reasonable suspicion of a violation, and officers were sufficiently certain those items were Dixon’s. The panel did not definitively resolve the searches of the Silvis home, Audi, and duffel bag because Dixon lacked standing.
Evidentiary hearing: Denial affirmed. A hearing is required only where a substantial claim presents disputed material facts. Dixon conceded there might not be significant factual disputes and did not offer a competing factual account.

Factual and Procedural Background

Following an October 20, 2019 hit‑and‑run involving a gray Mitsubishi, officers recovered guns, ammunition, suspected crack cocaine, a scale, cannabis, an Audi key, a rental agreement in Dixon’s mother’s name, and a photo of Dixon. A trooper identified Dixon as the driver. The probation office obtained an arrest warrant and a petition to revoke supervised release.

On December 18, 2019, officers arrested Dixon at a probation appointment after observing him arrive in a purple Pontiac. He had a key ring with an Audi fob. Invoking his supervised‑release search condition, officers:

Searched the Pontiac and found a locked cellphone, a marijuana cigarette, and a small scale;
Guessed the phone’s passcode and found texts referencing cannabis distribution and directing recipients to an address in Silvis, Illinois, plus images of Dixon with cannabis and a white Audi with a specific license plate;
Searched the East Moline residence Dixon had reported (not challenged on appeal);
Went to the Silvis house mentioned in texts, used Dixon’s keys to enter, and found a white Audi parked behind (within the curtilage), which they unlocked with the Audi fob;
Recovered from a duffel bag in the Audi two vacuum‑sealed cannabis packages, a handgun, and ammunition.

A federal jury convicted Dixon on six counts; only counts 4–6 (stemming from December 18) were challenged on appeal via the denied suppression motion.

Analysis

Precedents Cited and Their Influence

Standing and privacy interests: Rakas v. Illinois (Fourth Amendment rights are personal); United States v. Salvucci (no automatic standing; defendant must show own rights were violated); United States v. Carlisle; United States v. Mendoza, Meyer, Ruth (denials where defendants failed to produce evidence of a privacy interest). These cases anchored the court’s insistence that Dixon submit evidence of his subjective expectation of privacy and control.
Government assertions are not evidence: United States v. Diaz; Campania Management Co. v. Rooks, Pitts & Poust (lawyer assertions cannot support findings). Ninth and Eighth Circuit support: United States v. Zermeno; United States v. Maxwell; United States v. Long (defendants cannot rely on government pleadings to establish standing). The panel adopted this approach to reject Dixon’s reliance on the government’s positions and to admonish the district court’s acceptance of unsupported facts.
Use‑immunity for standing testimony: Simmons v. United States (testimony to establish standing cannot be used as direct evidence of guilt). The court flagged Simmons to explain why defendants can safely submit affidavits or testify solely to prove privacy interests.
Standard of review: Ornelas v. United States (de novo for probable cause/reasonable suspicion on settled facts); Bufkin v. Collins (2025) reaffirming that principle; U.S. Bank v. Village at Lakeridge (hybrids of fact/law). These framed the appellate lens.
Burden to justify warrantless searches: Coolidge v. New Hampshire; United States v. Longmire (government bears burden to show reasonableness when no warrant). The panel criticized the government’s failure to present evidence at the suppression stage.
Appellate use of trial evidence: United States v. Howell; Longmire (appellate courts may consider trial evidence to review suppression rulings, balancing risk of prejudice and avoiding windfalls). Here, trial evidence supported reasonableness without unfair prejudice to Dixon.
Supervised‑release/probation search doctrine: United States v. Knights (reasonable suspicion plus search condition suffices); Samson v. California (parolee searches; diminished privacy); United States v. White; United States v. Caya; United States v. McGill (applying Knights to federal supervised release). These authorities set the baseline balancing test and thresholds.
Scope: whose property may be searched: Eighth and Ninth Circuits require high certainty for residences: United States v. Thabit (probable cause a residence is the parolee’s before warrantless “residence” search); Motley v. Parks. For vehicles and items: United States v. Dixon (9th Cir. 2020) and United States v. Bolivar (reasonable suspicion regarding control of items). The Seventh Circuit signaled alignment in principle: the government must prove the property searched is sufficiently controlled by the supervisee to fall within the condition.
Curtilage and physical intrusion: Florida v. Jardines (entry into curtilage to gather information is a search); United States v. Jones (physical trespass theory). These underscore that entering a home’s curtilage to discover the Audi was itself a search needing justification.
“Fruit of the poisonous tree”: Utah v. Strieff; Segura v. United States. If entry onto the Silvis property was unlawful, derivative evidence from the Audi/duffel could be suppressible—though Dixon lacked standing to raise it.
Miscellaneous: Wyoming v. Houghton (reasonableness balancing); Illinois v. Gates (probable cause totality); United States v. Castetter and McMurtrey (warrant particularity/affidavit norms, used here for analogy); United States v. Gibbs (prosecutor statements aren’t substitutes for testimony); United States v. Simon; Florida v. Harris (probable cause’s “fair probability”); United States v. Wood (parolee exception applied to phone found in home); United States v. Berkowitz (home as core of Fourth Amendment protections); United States v. Jackson (others may have civil claims for unlawful entry); United States v. Harris, Edgeworth, Curlin, McGaughy (hearing standards); Byrd v. United States (standing not jurisdictional; order of operations flexible); Cellitti (government can concede standing); Stewart v. McGinnis (civil summary judgment analogy about evidentiary support for facts).

Legal Reasoning

1) Standing: A defendant’s evidentiary burden is real—and was unmet

The court reaffirmed that Fourth Amendment standing is part of the merits. The defendant must prove a personal privacy interest in both the item and the place where the item is found. Dixon offered only conclusory assertions with no affidavit, testimony, or other evidence—despite Simmons protection from the use of that testimony at trial. The panel stressed that defendants may not rely on the government’s pleadings or positions to establish standing. Because Dixon failed to establish a subjective expectation of privacy in the Pontiac, Silvis house, Audi, or duffel bag, he lacked standing to challenge searches of those areas or the items within them (including the phone and duffel).

The district court’s separate finding that Dixon disclaimed connections to the searched property was unsupported by evidence. While such disclaimers can defeat standing, the government failed to present proof of them. The error in relying on unsupported assertions was harmless because the absence of any defense evidence on standing independently doomed the motion.

2) The government’s burden to justify warrantless searches and the problem of unsupported factual assertions

Warrantless searches invert the usual presumption; the government must prove reasonableness. The panel criticized the government’s reliance on attorney assertions rather than officer affidavits or testimony, and admonished the district court for accepting such assertions. The court underscored the constitutional preference for warrants and insisted that when a warrant is absent, the government must supply evidence comparable in reliability to what a warrant would have required (e.g., sworn affidavits). Nevertheless, the panel reviewed trial evidence (consistent with Howell and Longmire) to avoid a windfall reversal, determining there was no unfair prejudice to Dixon and no materially new facts introduced at trial beyond those flagged pretrial.

3) Scope and triggers of the supervised‑release search condition

Dixon’s condition authorized searches of “his person, property, residence, adjacent structures, office, vehicle, papers, computers … and other electronic communications or data storage devices or media” when “reasonable suspicion exists that the defendant has violated a condition of his release and/or that the area(s) or item(s) to be searched contain evidence of this violation or contain contraband.”

Disjunctive trigger confirmed: The court read “and/or” to permit a search based on reasonable suspicion of a violation alone. Knights supports this reading: when an officer has reasonable suspicion that a supervisee subject to a search condition is engaged in criminal activity, the supervisee’s diminished privacy interests render a search reasonable.
Whose property may be searched: The condition reaches only the supervisee’s property and cannot authorize searches of third-party property without consent or independent justification. The Seventh Circuit held the government must show the areas or items are “sufficiently controlled by or connected to the defendant” to fall within the condition. The court left “the contours” for future cases but suggested higher certainty is required for homes, aligning with the Eighth and Ninth Circuits’ residence-focused standards. Applying any plausible standard, officers were sufficiently certain the Pontiac and cellphone were Dixon’s (he drove the Pontiac alone; the phone was unlocked using knowledge unique to Dixon; he had no other phone on his person). By contrast, the Silvis home presented a closer question: Dixon’s reported residence was elsewhere, and the linkage to Silvis arose only from texts. Because Dixon lacked standing, the panel did not resolve whether the Silvis search, entry onto curtilage, and subsequent Audi/duffel search were authorized.
Reasonable suspicion existed: Independent of the above, officers had reasonable suspicion of violations (and indeed probable cause) arising from the October hit‑and‑run investigation: guns, ammunition, distribution‑scale drug quantities in the Mitsubishi, the Audi key, the trooper’s identification of Dixon, and a judicial probable‑cause finding supporting an arrest warrant.

4) Evidentiary hearing

A hearing is required only where a substantial claim presents disputed issues of material fact. Dixon conceded there may not be significant factual disputes and did not proffer a competing factual narrative. Identifying gaps in the government’s proof is not the same as framing specific, material factual disputes. Denial of a hearing was within the district court’s discretion.

Impact

A. District court practice: Unsupported factual “statements” cannot do the work of evidence

The Seventh Circuit’s explicit criticism will likely reshape suppression practice in the Central District of Illinois and beyond. Absent a clear stipulation, courts must base findings on record evidence—affidavits, testimony, exhibits—not lawyer assertions. Expect more frequent requirements that parties file evidentiary submissions with suppression briefs and clearer local procedures to ensure an adequate pretrial record.

B. Defense strategy: Prove standing or lose

The opinion is a cautionary tale: without an affidavit or testimony establishing a privacy interest and control, suppression challenges fail at the threshold. Simmons protects a defendant’s standing testimony from use as direct evidence of guilt. Counsel should:

File targeted affidavits establishing possessory interests, control, access, and right to exclude;
Request a Simmons hearing if needed;
Propose stipulations where feasible; and
Identify specific, material factual disputes to secure an evidentiary hearing.

C. Government obligations in supervised‑release searches

When invoking a supervised‑release condition to justify a warrantless search, the government must be prepared to prove:

Control/connection: The searched area or item was sufficiently controlled by the supervisee to fall within the condition (especially stringent for residences);
Trigger: Reasonable suspicion of a violation (or evidence/contraband in the area, per the condition’s disjunctive phrasing); and
Reasonableness: Under the totality, balancing diminished privacy expectations and strong supervisory interests.

For residences not known to be the supervisee’s, the panel signaled agreement with requiring heightened certainty (possibly probable cause) that the dwelling is indeed the supervisee’s. Curtilage entries remain Fourth Amendment “searches” and must be justified. Officers should anticipate suppression challenges by documenting ownership, control, keys, registration, admissions, or other reliable indicia linking the property to the supervisee.

D. Smartphones under supervision

Ordinarily, a cellphone search requires a warrant (Riley v. California). But for supervisees, diminished privacy expectations coupled with a search condition and reasonable suspicion can justify warrantless searching of a phone that is the supervisee’s. The panel’s application to the phone found in the Pontiac—unlocked using Dixon-specific information—reinforces that nexus and suspicion matter. Officers should still carefully chronicle how they concluded the device belonged to the supervisee.

E. Curtilage and third-party rights

The panel highlighted that entry onto the Silvis home’s curtilage to locate and search the Audi was a search (Jardines/Jones). Even if a supervisee cannot contest it for lack of standing, non‑supervisee owners or residents might pursue civil remedies (Jackson). This dual track—suppression unavailing for the defendant but potential civil liability for officers—will influence supervisory practices at multi-occupant locations.

Complex Concepts Simplified

Fourth Amendment “standing”: A shorthand for a merits requirement: only someone whose own privacy rights were violated may suppress evidence. To show this, the defendant must prove a legitimate (societally recognized) expectation of privacy in the place searched and the item seized.
Reasonable suspicion vs. probable cause: Reasonable suspicion is a lower standard—specific, articulable facts suggesting wrongdoing, viewed in the totality. Probable cause is a fair probability that evidence of a crime will be found in a place or that a person committed a crime.
Supervised‑release search condition: A court‑imposed term that reduces a supervisee’s privacy expectations and permits warrantless searches under specified triggers (e.g., reasonable suspicion of violations). The Seventh Circuit treated “and/or” language as disjunctive: reasonable suspicion of a violation alone can trigger a search.
Control/ownership nexus: For officers to rely on a supervisee’s search condition, the searched area or item must be sufficiently connected to the supervisee (e.g., the person’s car, phone, bedroom, or bag). Third‑party property lies outside the condition absent consent or other lawful basis.
Curtilage: The area immediately surrounding a home that receives the same core protections as the home itself. Physically entering curtilage to gather information is a search requiring justification.
Fruit of the poisonous tree: Evidence derived from an unlawful search or seizure may be excluded unless an exception applies.
Simmons immunity: A defendant’s testimony given to establish a privacy interest for suppression cannot be used as direct proof of guilt at trial.

Conclusion

United States v. Dixon sets out a clear, disciplined framework for suppression litigation in supervised‑release cases. The Seventh Circuit:

Emphatically rejected reliance on unsupported attorney assertions to resolve suppression motions;
Reaffirmed the defendant’s burden to prove a personal privacy interest and refused to treat government positions as evidence;
Clarified that supervised‑release search conditions apply only to the supervisee’s property, requiring the government to prove a sufficient control/connection, with special caution around residences;
Interpreted “and/or” search triggers disjunctively: reasonable suspicion of a violation by a supervisee suffices to authorize a search under Knights; and
Permitted use of trial evidence on appeal to support suppression rulings when doing so avoids a windfall reversal without prejudicing the defendant.

For police, probation, and prosecutors, Dixon demands evidentiary rigor—affidavits and testimony, not advocacy, to justify warrantless searches. For defense counsel, it reinforces that standing is an evidentiary hurdle that must be cleared with proof, safeguarded by Simmons. For district courts, it counsels against expedient reliance on unproven factual narratives. Substantively, the opinion both hews to the established Knights/Samson line and signals a maturing Seventh Circuit approach to the “whose property” question in supervision searches—likely requiring greater certainty, especially for homes. The decision thus offers both caution and clarity for future Fourth Amendment litigation at the intersection of supervision and search.