United States v. Blasdel: Tenth Circuit Clarifies Four-Corners Exclusivity and Denies Good-Faith Reliance for Affidavits Tainted by Pre‑Warrant Searches

Introduction

In United States v. Blasdel (10th Cir. Sept. 2, 2025) (published), the Tenth Circuit reversed a district court’s denial of a motion to suppress, vacated the defendant’s convictions and sentence, and remanded. The case arises out of a warrantless “peek” and entry into a rented storage unit by police, followed by two search warrants: one for the storage unit and another for the defendant’s home. The core issues were:

Whether officers’ pre-warrant actions inside a storage unit violated the Fourth Amendment;
Whether, after excising information derived from those unlawful entries, the affidavit still established probable cause under the four-corners rule;
Whether the Leon good-faith exception could save the storage-unit warrant; and
Whether the subsequent home warrant and search were fruit of the poisonous tree.

The panel held that the pre-warrant “peek” and entry were unconstitutional searches. Once the tainted material was excised, the storage-unit affidavit did not supply probable cause. The affidavit was also so facially deficient that the good-faith exception did not apply. Because the home warrant relied on the fruits of the first unlawful search, the home search evidence was also suppressed under the Tenth Circuit’s categorical rule that good faith does not apply to a warrant affidavit predicated on tainted evidence.

Summary of the Judgment

The Tenth Circuit (Judge Seymour) ruled:

Police officers violated the Fourth Amendment by physically intruding into a rented storage unit before obtaining a warrant—one officer “peeked” his head inside to view the four corners; another entered and opened a drawer. See United States v. Jones, 565 U.S. 400 (2012).
Applying the excision doctrine, the court removed the officers’ observations gleaned from the unlawful entry and then evaluated the four corners of the remaining affidavit. See United States v. Bullcoming, 22 F.4th 883 (10th Cir. 2022); United States v. Sims, 428 F.3d 945 (10th Cir. 2005).
After excision, the affidavit’s vague and ambiguous references to an “employee” allegedly seeing “illegal narcotics” failed to establish probable cause within the four corners. See United States v. Cotto, 995 F.3d 786 (10th Cir. 2021); United States v. Knox, 883 F.3d 1262 (10th Cir. 2018); Hackney, Inc. v. McLaughlin, 895 F.2d 1298 (10th Cir. 1990).
The Leon good-faith exception did not apply because the affidavit was “so facially deficient” that no reasonable officer could rely on it, particularly where the specificity came only from the officer’s own illegal observations. See United States v. Gaye, 130 F.4th 865 (10th Cir. 2025); Knox, 883 F.3d at 1272.
The home warrant, grounded on what had been recovered from the unlawful storage-unit search, was fruit of the poisonous tree. The Tenth Circuit reiterated that good faith categorically does not apply when an affidavit is based on tainted evidence from a prior unlawful search. See United States v. Loera, 923 F.3d 907, 926 (10th Cir. 2019); United States v. Mora, 989 F.3d 794 (10th Cir. 2021).

Result: Suppression of evidence from both the storage unit and the home; convictions vacated; case remanded.

Factual Background in Brief

Storage-facility employees (private actors) entered a unit with its door slightly open under their rental agreement and observed a gun, baggies, a money counter, scales, and apparent contraband. They called police.
Officer Doyle arrived and “peeked” his head inside the unit to see the four corners and observed suspected methamphetamine and other items.
Officer Lemmons arrived, peered in, then entered the unit and opened a drawer, at the district attorney’s request to “have eyes on” suspected methamphetamine. He later drafted a warrant affidavit for the unit describing seeing “a white crystalline substance,” baggies, scales, a firearm, and a currency counter.
A judge issued the storage-unit warrant; officers seized roughly four pounds of methamphetamine and firearms.
Based on that discovery, Lemmons then obtained a warrant for the defendant’s residence, citing the drugs and guns recovered and the risk of destruction; that search yielded additional drugs and firearms.
The district court denied a motion to suppress; the defendant entered a conditional guilty plea reserving the suppression issue for appeal.

Analysis

Precedents Cited and Their Influence

United States v. Jones, 565 U.S. 400 (2012): The Court invoked Jones to anchor the conclusion that physically intruding into a constitutionally protected space (here, the interior of a storage unit) is a “search.” The officers’ head-and-shoulders intrusion and drawer opening crossed the threshold and thus required a warrant or exception.
United States v. Lowe, 117 F.4th 1253 (10th Cir. 2024): Cited for the proposition that people generally have a legitimate expectation of privacy in storage units. This confirmed that a renter (or someone paying for and associated with the unit) enjoys Fourth Amendment protection.
United States v. Muhtorov, 20 F.4th 558 (10th Cir. 2021) and United States v. Santiago, 135 F.4th 1235 (10th Cir. 2025): Standards of review—clear error for factual findings, de novo for legal conclusions.
United States v. Bullcoming, 22 F.4th 883 (10th Cir. 2022) and United States v. Sims, 428 F.3d 945 (10th Cir. 2005): The “excision” rule. When a warrant affidavit contains unconstitutionally obtained information, courts remove that material and evaluate whether the remaining content establishes probable cause. This framework controlled the storage-unit warrant analysis.
United States v. Cotto, 995 F.3d 786 (10th Cir. 2021) and United States v. Knox, 883 F.3d 1262 (10th Cir. 2018): Articulate the “fair probability” standard and the critical “four-corners” limitation—probable cause must be assessed based on what the issuing judge was told in the affidavit (and any sworn statements made to the judge pre-issuance), not what is later developed at a suppression hearing.
Hackney, Inc. v. McLaughlin, 895 F.2d 1298 (10th Cir. 1990): Reinforces the four-corners doctrine. The government cannot retrofit an inadequate affidavit with testimony elicited later.
United States v. Gaye, 130 F.4th 865 (10th Cir. 2025): Clarifies the Leon good-faith presumption and its limits. The presumption is lost when the affidavit is so facially deficient that no officer could reasonably rely on it. The court applied Gaye to find the storage-unit affidavit facially deficient due to vagueness and reliance on unlawful observations.
United States v. Mora, 989 F.3d 794 (10th Cir. 2021): Affidavits for subsequent warrants must be cleansed of tainted material; otherwise, they lack probable cause.
United States v. Loera, 923 F.3d 907, 926 (10th Cir. 2019): The Tenth Circuit’s categorical rule that the Leon good-faith exception does not apply when a warrant affidavit is based on tainted evidence from a prior unlawful search. This foreclosed the government’s good-faith argument as to the home warrant.

Legal Reasoning

Fourth Amendment violation in the storage unit:
- The court accepted that private storage employees’ entry did not trigger the Fourth Amendment. But to the extent police also entered or intruded across the threshold before a warrant, that conduct was judged by constitutional standards.
- Officer Doyle’s head across the threshold to view the four corners, and Officer Lemmons’s entry and opening of a drawer, were searches without a warrant or exception and thus unreasonable under Jones.
Excision and the four-corners review of the storage-unit affidavit:
- The affidavit contained two types of content:
  - Vague statements that an “employee” believed items in plain view were illegal narcotics, with no specific description of the items, who saw them, or the basis of that belief.
  - Precise descriptions of a “white crystalline substance,” scales, baggies, a firearm, and a currency counter—but those specific observations came from the officers’ unlawful entry and had to be excised.
- After excising the officers’ observations, the remaining affidavit—shorn of detail—failed to give the issuing judge a concrete factual basis to find a fair probability of contraband. The court emphasized that later testimony at the suppression hearing could not cure the affidavit’s vagueness because of the four-corners rule.
Good-faith exception as to the storage-unit warrant:
- Although Leon ordinarily presumes good-faith reliance on a judge-issued warrant, that presumption disappears when the affidavit is “so facially deficient” that reliance is unreasonable.
- Here, the only specificity came from unlawfully obtained observations. The affidavit’s remaining vagueness about an “employee” belief, without identifying the observer, describing the items, or providing a basis for the belief, was facially deficient. Officers could not reasonably rely on such an affidavit.
- Critically, the good-faith assessment is also limited to the four corners (and any sworn pre-issuance input to the issuing judge). Post hoc elaboration at a suppression hearing is irrelevant to the Leon analysis.
The home warrant and fruit of the poisonous tree:
- The home-affidavit’s nexus rested on what had been seized from the storage unit (several pounds of methamphetamine, firearms) and the inference that more evidence might be at the residence.
- Once the storage-unit discovery is excised as tainted, the home affidavit provides no reason to believe evidence would be at the residence beyond the defendant’s status as a felon who knew police were at the unit. That is insufficient for probable cause.
- Under Loera, the good-faith exception does not apply when a warrant affidavit is tainted by an earlier unlawful search. Suppression of the home search evidence was therefore required.

Impact and Significance

Blasdel has immediate and practical consequences for Fourth Amendment practice in the Tenth Circuit:

Four-corners rigor reinforced: Affiants must provide concrete, source-specific facts. Ambiguous attributions (“an employee believed…”) with no details will not satisfy probable cause—especially where precise facts in the affidavit trace to unlawful observations.
No “confirmatory” pre-warrant searches: The opinion explicitly rejects the practice of entering or peering inside to “confirm” civilian tips before seeking a warrant. Such confirmatory steps taint the affidavit and risk suppression.
Leon’s limits sharpened: Where an affidavit’s adequacy depends on illegal observations, and the remaining content is vague or conclusory, the good-faith exception will not save the warrant. Officers and prosecutors cannot rely on post hoc testimony to shore up the affidavit.
Cascading suppression: The court’s reliance on Loera makes clear that secondary warrants relying on tainted fruits are not salvageable via good-faith in this circuit. This can unwind entire investigations if the first step is constitutionally flawed.
Storage-unit jurisprudence: The Tenth Circuit affirms a robust expectation of privacy in storage units (Lowe). Even where a facility’s staff may enter under a contract, that does not create a police license to do so. Crossing the threshold is constitutionally significant.

Complex Concepts Simplified

Four-corners doctrine: When a judge decides whether to issue a warrant, the analysis is limited to the information within the four corners of the affidavit (and any sworn material presented to the judge before issuance). Later testimony at a suppression hearing cannot retroactively bolster probable cause.
Excision doctrine: If an affidavit includes facts obtained through an illegal search, courts “excise” (remove) those facts and then ask whether the remaining content establishes probable cause. If not, the warrant fails.
Probable cause: Requires a “fair probability” that evidence of a crime will be found in the place to be searched. Conclusory assertions or unspecified beliefs, without detailed supporting facts, generally do not meet this standard.
Good-faith exception (Leon): Evidence may be admissible if officers objectively and reasonably relied on a warrant, even if the warrant later proves defective. But good faith does not apply when the affidavit is facially deficient or when the warrant is based on tainted evidence from an earlier illegal search (in the Tenth Circuit).
Fruit of the poisonous tree: Evidence discovered as a direct or indirect result of an unconstitutional search is typically excluded. Exceptions (e.g., independent source, inevitable discovery, attenuation) were not at issue or applied here.
Plain view: For police, “plain view” requires a lawful vantage point. If the officer must unlawfully cross a threshold to see the item, the plain-view doctrine does not apply.

Practice-Focused Guidance

For law enforcement and affiants:

Do not cross thresholds or open containers/drawers pre-warrant. If private actors have already looked, document what they saw through interviews; do not “recreate” or exceed their view without a warrant.
Identify the source of information in the affidavit. If a private citizen observed contraband, say who, what they saw, when, where, and why they believed it was contraband. Avoid vague, conclusory phrasing.
Record any sworn oral testimony to the issuing judge. If additional facts are provided orally, ensure they are under oath and memorialized for later review.
Resist “confirmatory” intrusions at the request of supervisors or prosecutors. Institutional pressure to “have eyes on” is not a Fourth Amendment exception.

For prosecutors:

Train affiants to segregate and label lawful sources, and to exclude tainted observations. If tainted facts are necessary to the narrative, their excision will likely defeat probable cause and Leon.
Consider whether independent-source or inevitable-discovery theories are available and properly supported; absent that, derivative warrants are vulnerable in the Tenth Circuit due to Loera.

For defense counsel:

Scrutinize affidavits for ambiguous attributions and conclusory statements. Demand excision of tainted content and insist on four-corners review, not suppression-hearing embellishments.
Invoke Loera to challenge good-faith arguments for derivative warrants that rest on tainted information.

Notable Passages from the Opinion

“The affidavit cannot be supplemented, for purposes of a probable cause determination, by additional testimony at a hearing on a motion to suppress. The government cannot use such a hearing as a second chance to clarify what it meant to include or later realized it should have included in the original affidavit.”

“The affidavit’s phrasing is so facially deficient that Officer Lemmons could not reasonably have presumed it to be valid. We hold that the good faith exception does not apply in this case.”

“Tenth Circuit precedent dictates that the good faith exception does not apply at all when a warrant affidavit is based on tainted evidence from a prior, unlawful search.”

Conclusion

United States v. Blasdel is a forceful reaffirmation—and practical sharpening—of core Fourth Amendment protections in the Tenth Circuit. It clarifies that:

Even minimal pre-warrant threshold intrusions into private spaces like storage units are unconstitutional searches absent an exception;
Affidavits must stand or fall on the four corners and cannot be salvaged later with hearing testimony;
Vague references to civilian “beliefs” are insufficient to establish probable cause without factual specifics; and
Good-faith reliance will not rescue warrants that depend on tainted observations or that are facially deficient, and it categorically does not apply to derivative warrants relying on tainted fruits in this circuit.

The decision sends a clear institutional message: Do not “confirm” suspicions by entering before a warrant, and draft affidavits with source clarity and factual detail. Blasdel will likely influence how law enforcement approaches storage-unit investigations, how prosecutors coach affiants, and how district courts police the boundary between lawful reliance on civilian reports and improper, confirmatory police searches. It underscores that the constitutional remedy—exclusion—remains robust where officers cross the line and then obscure that crossing in the warrant process.