Good-Faith Exception Denied When Agents Knowingly Search a Different Device Than the Warrant Specifies

1. Introduction

In United States v. Gonzalez-Arocho (1st Cir. July 9, 2026), the First Circuit addressed whether the good faith exception to the exclusionary rule can save evidence obtained when federal agents execute a search warrant for a specifically described iPhone (by model and IMEI), but knowingly seize and search a different iPhone.

Homeland Security Investigations (HSI) obtained a warrant authorizing the search of an Apple iPhone 6S 64GB with a specific IMEI ending in -1711 and a phone number ending in -7611. When executing the warrant, agents seized from Miguel González-Arocho an iPhone 13 Pro Max associated with the same phone number, searched it immediately, and later found over 100 child-pornography files. González was indicted under 18 U.S.C. § 2252(a)(4)(B) and § 2252(a)(2) and moved to suppress the phone evidence.

The government ultimately conceded on appeal that the iPhone 13 search exceeded the warrant’s scope; the sole question became whether suppression was nonetheless unwarranted under the good faith exception.

2. Summary of the Opinion

The First Circuit affirmed the suppression order. It held the government did not carry its “heavy burden” to show objective good faith where:

  • the warrant unambiguously authorized a search of a specific device (iPhone 6s) identified by IMEI; and
  • agents immediately recognized they had seized a different model iPhone yet made no effort to resolve the discrepancy (e.g., by asking about the iPhone 6s or obtaining a new warrant) before searching the iPhone 13.

The court also clarified that lack of exigency is not an automatic bar or trigger for good faith; it matters only insofar as it bears on whether an officer’s understanding of the warrant’s scope at execution was objectively reasonable.

3. Analysis

3.1. Precedents Cited

  • United States v. Vick and United States v. Rivera: The court reiterated the mixed standard of review for suppression decisions (facts for clear error, law de novo) and the requirement to view facts in the light most favorable to the district court’s ruling.
  • United States v. Sheehan: Used for the principle that an appellate court may affirm a suppression ruling on any ground “made manifest in the record.”
  • United States v. Woodbury: Cited both for de novo review of the good faith exception and as a contrast: good faith applied there because police refrained from searching the wrong apartment after learning it was wrong—illustrating that diligence and course-correction support good faith, while pressing ahead despite red flags does not.
  • United States v. Medina (quoting United States v. Wright): Framed the posture: once a Fourth Amendment violation is assumed, “the sole question” becomes whether suppression is required. Also emphasized that even “unintentional mistakes” can defeat good faith if exclusion would deter the conduct.
  • United States v. Gonzalez and United States v. Wurie: Supplied the “heavy burden” formulation for the government and reinforced strict scrutiny of smartphone searches in the suppression context.
  • Herring v. United States: Central to the opinion’s framework: exclusion’s purpose is deterrence of deliberate, reckless, or grossly negligent conduct; the good-faith inquiry asks whether a reasonably well-trained officer would have known the search was illegal in light of all circumstances, including officer knowledge and experience.
  • United States v. Levin and United States v. Leon: Provided the modern articulation of the good faith exception and the idea that exclusion is inappropriate where officers act in objective good faith or the transgression is minor—while also anchoring the “reasonably well trained officer” standard.
  • United States v. Pimentel and United States v. Brunette: Pimentel supplied the “no bright-line test” approach and the focus on warrant language plus attendant circumstances. The government relied heavily on Pimentel to argue that minor descriptive errors can be cured by reasonable on-scene inference; the court distinguished Pimentel because the warrant here was not ambiguous and agents did not verify facts before searching.
  • Riley v. California: Used to underscore the heightened privacy stakes in smartphone searches—making careful adherence to warrant limits especially important.
  • United States v. Underwood: Cited for the proposition that correct physical details in a phone warrant help ensure officers search the correct phone—supporting the First Circuit’s insistence that device descriptors (like IMEI) matter.
  • United States v. Moss: Addressed by the court largely to reject the government’s analogy: Moss concerned particularity and a clerical mismatch where a unique tracking number and officer familiarity cured the problem; here, by contrast, the unique identifier (IMEI) pointed away from the iPhone 13 and agents knew the device differed.
  • Maryland v. Garrison: Quoted for the duty to make a “reasonable effort to ascertain and identify the [place] intended to be searched”—adapted here to the duty to ascertain and identify the correct device when executing a device-specific warrant.
  • United States v. Giambro: Used by analogy for a broader reasonableness principle: officers may not ignore obvious and available options for gathering facts before acting.
  • United States v. Lickers: Cited for the idea that Leon encourages “responsible and diligent police work,” supporting deterrence-based suppression where diligence was lacking.

3.2. Legal Reasoning

The court’s reasoning is organized around two pillars: (1) the warrant’s unambiguous scope and (2) the officers’ objectively unreasonable execution.

(a) The warrant was device-specific and unambiguous

The warrant did not merely authorize a search for evidence associated with a phone number. It defined “the DEVICE” as an Apple iPhone 6S 64GB and identified it by a unique IMEI. The warrant repeatedly referenced that defined “DEVICE,” making clear that the authorized forensic search was constrained to that particular hardware.

The government argued that the phone number was the true “focus,” rendering the model/IMEI nonessential. The court rejected this as inconsistent with both the warrant’s text and the affiant’s theory of probable cause: evidence would be stored “within” the phone’s hardware and memory, so the described device was integral to the authorization.

The court also highlighted the modern reality—echoing Riley v. California—that smartphones contain vast private information and are akin to “minicomputers,” so courts must be cautious about expanding a warrant beyond its terms.

(b) Objective good faith failed because agents knew they had the wrong device and did not reconcile the mismatch

The decisive facts were practical and contemporaneous. The executing agent testified he could recognize iPhone models and admitted that he knew “by seeing it” that the seized phone was an iPhone 13, not an iPhone 6s. He recorded the iPhone 13 on the inventory form the same day—supporting the district court’s finding that the mismatch was understood immediately.

From there, the court faulted the execution in three related ways:

  • Omission of limiting warrant details during explanation: When speaking to González, agents described the warrant as covering “an Apple iPhone” tied to the phone number, but did not mention the iPhone 6s model or the IMEI. The court treated this as undermining any claim that agents reasonably believed they were within the warrant’s bounds.
  • No meaningful opportunity for the target to identify the mismatch: Although agents handed González a copy of the warrant, it was in English while the interaction and Miranda advisement were in Spanish. The court emphasized they never confirmed he understood English—so the paper handoff did not cure the agents’ narrowing omissions.
  • Failure to take “obvious and available” steps to verify authorization: Even if it was plausible that González had upgraded phones, the agents never asked whether he still possessed the iPhone 6s, whether data had been transferred, or where the iPhone 6s was located. Under Maryland v. Garrison and the reasonableness logic echoed in United States v. Giambro, the court treated this failure to inquire as incompatible with “objective good faith.”

Importantly, the First Circuit agreed that lack of exigency is not itself dispositive. It matters only as part of “all of the circumstances” bearing on what a reasonably trained officer would understand at the moment of execution. Here, those circumstances made the illegality apparent enough that proceeding without clarification (or a new warrant) was objectively unreasonable.

3.3. Impact

The decision strengthens a clear operational rule for digital searches in the First Circuit: when a warrant is device-particularized (especially by unique identifiers like IMEI), officers cannot rely on good faith to justify searching a different device merely because it shares an associated phone number or seems like an “upgrade.”

Likely downstream effects include:

  • Execution protocols: Investigators will need checklists and training emphasizing verification of device identifiers at the scene (model/IMEI/serial), and documenting steps taken to resolve discrepancies.
  • Warrant drafting: Agents and prosecutors may seek warrants that anticipate replacement/upgrade scenarios (e.g., authorizing search of a described device and any replacement device associated with the same subscriber/number, supported by probable cause and particularity) to reduce mismatch risk.
  • Suppression litigation: The opinion provides a roadmap for defendants to challenge searches where officers recognize, or should recognize, a mismatch but proceed anyway. The government will face a steep burden to show “objective good faith” without evidence of immediate verification efforts.

4. Complex Concepts Simplified

  • Exclusionary rule: A court-made rule that can bar evidence obtained through unconstitutional searches/seizures, primarily to deter police misconduct.
  • Good faith exception: Even if a search is unconstitutional, evidence may still be admitted if officers acted reasonably—i.e., a well-trained officer would not have known the search was illegal in light of the circumstances.
  • Objective good faith: Not about an officer’s sincere belief; it asks whether the belief was reasonable from the standpoint of a trained officer.
  • Particularity: The Fourth Amendment requires warrants to describe with specificity what may be searched and seized. For devices, unique identifiers (like IMEI) help ensure the correct phone is searched.
  • IMEI: A unique identifier for a cellular device—functionally akin to a serial number used to distinguish one phone from another.
  • Exigency: Emergency circumstances that can justify acting without a warrant (e.g., imminent destruction of evidence). Here, the point was not that exigency was required for good faith, but that absent exigency, it was more reasonable to expect agents to pause and clarify/seek a new warrant.

5. Conclusion

United States v. Gonzalez-Arocho establishes a practical and protective rule for digital-search execution: when a warrant authorizes a search of a specifically identified device (by model and IMEI), and agents recognize they have seized a different device, the government cannot invoke the good faith exception unless officers take reasonable steps to reconcile the mismatch. The opinion reinforces heightened care for smartphone searches under Riley v. California and aligns the good-faith doctrine with its deterrence purpose under Herring v. United States and United States v. Leon.