State v. Ellis: Open-Driveway Encounters—No Search When Evidence Is Voluntarily Produced, and Miranda Not Required During Noncustodial Driveway Questioning

Introduction

In State v. Z. Ellis, 2025 MT 253, the Supreme Court of Montana affirmed a DUI conviction arising from an unusual set of facts: a single-vehicle crash, eyewitness reports that the driver “passed out,” and the driver’s admission that he had “huffed” a can of Dust-Off (difluoroethane, or DFE). The case presented five issues: (1) whether officers had particularized suspicion to investigate for DUI; (2) whether the investigation involved an unlawful search or seizure; (3) whether statements were obtained in violation of Miranda; (4) whether an evidentiary foundation challenge to blood-test results was preserved for appeal; and (5) whether the evidence was sufficient to support the conviction.

The Court’s opinion clarifies several recurring points in Montana criminal procedure and search-and-seizure law:

The “escalating encounter” doctrine permits officers to expand a crash investigation into a DUI investigation when new facts arise during the stop.
Open, publicly accessible driveways generally do not afford a reasonable expectation of privacy; officers who lawfully approach may look into a vehicle’s window from such a location.
No Fourth Amendment or Article II, Section 11 “search” occurs when a suspect voluntarily retrieves and hands evidence to officers.
Brief, noncoercive questioning at the edge of a driveway in public view during an investigatory stop is not “custodial interrogation,” and Miranda warnings are not required prior to arrest.
Appellants must preserve issues through the intermediate appeal (from justice court to district court) or they are waived for Supreme Court review.

Summary of the Opinion

The Court affirmed the Justice Court’s denial of Ellis’s suppression motions and the District Court’s intermediate appellate affirmance. On particularized suspicion, the Court held officers lawfully expanded a crash investigation into a DUI investigation based on 911 reports, physical damage, and Ellis’s demeanor and admissions. On the search-and-seizure claim, the Court concluded there was no objectively reasonable expectation of privacy in an open, publicly accessible driveway and that Ellis voluntarily produced the Dust-Off can—so no “search” occurred. On Miranda, the Court held that the driveway questioning was an on-the-scene investigatory encounter, not custodial interrogation. On evidentiary foundation, the Court declined review because Ellis did not raise the issue in the intermediate appeal. Finally, considering the evidence in the light most favorable to the State, the Court held that Ellis’s admissions, the crash evidence, and the toxicology report detecting DFE provided sufficient evidence of DUI.

Detailed Analysis

1) Precedents Cited and How They Shaped the Decision

Particularized Suspicion and the Escalating Encounter

State v. Gopher, 193 Mont. 189, 631 P.2d 293 (1981): The classic two-part test for particularized suspicion—(1) objective data from which an experienced officer can make certain inferences; and (2) a resulting suspicion of wrongdoing. The Court applied Gopher to conclude that the crash, eyewitness reports, physical evidence, Ellis’s demeanor, and his admissions together provided objective data supporting reasonable inferences of DUI (¶¶ 18–21).
Hulse v. State, 1998 MT 108, 289 Mont. 1, 961 P.2d 75: Erratic driving can provide particularized suspicion and illustrates “an escalating situation” in which officers may administer SFSTs. The Court expressly invoked Hulse’s “escalating situation” characterization (¶ 21), emphasizing that new facts gleaned from the encounter justified expanding the scope.
State v. Stanley, 2024 MT 271, 419 Mont. 61, 558 P.3d 1147: Officers may expand the scope of an investigative stop beyond its initial purpose based on additional information (¶ 20). Stanley underpins the move from crash-response to DUI investigation.
State v. Harning, 2022 MT 61, 408 Mont. 140, 507 P.3d 145; State v. Wilson, 2018 MT 268, 393 Mont. 238, 430 P.3d 77: Officers need not be certain—or even correct—about criminal activity to have particularized suspicion (¶ 20).
State v. Zietlow, 2017 MT 148, 388 Mont. 26, 396 P.3d 740; State v. Gill, 2012 MT 36, 364 Mont. 182, 272 P.3d 60: Particularized suspicion is assessed under the totality of the circumstances (¶ 20).

Search and Seizure; Privacy Expectations in Driveways

State v. Goetz, 2008 MT 296, 345 Mont. 421, 191 P.3d 489: Provides the three-part privacy analysis: (1) actual subjective expectation of privacy; (2) one society recognizes as objectively reasonable; and (3) nature of the State’s intrusion (¶ 24). The Court determined Ellis manifested no privacy expectation in an open driveway and that the setting was accessible to the public (¶¶ 29–31).
State v. Bullock, 272 Mont. 361, 901 P.2d 61 (1995): In Montana, privacy can be recognized beyond the curtilage if fencing, signs, or other means “unmistakably” indicate entry is not permitted (¶ 24–25). Bullock sets the high-water mark for Montana’s privacy protections and also highlights the importance of signage or other exclusionary indicators—which were absent here.
State v. Smith, 2021 MT 324, 407 Mont. 18, 501 P.3d 398: An open gate and absence of indicators barring entry undermined any objectively reasonable expectation of privacy in a driveway; however, when the occupant told the deputy he was trespassing and to leave if he had no warrant, that assertion crystallized a reasonable expectation. The Court found no similar assertion by Ellis (¶¶ 27, 29).
State v. Lanchantin, 2024 MT 129, 417 Mont. 27, 550 P.3d 790: A secluded driveway, reached by private easement and marked “No Trespassing,” carried an actual expectation of privacy (¶ 28). By contrast, Ellis’s suburban setting lacked comparable markers.
City of Whitefish v. Large, 2003 MT 322, 318 Mont. 310, 80 P.3d 427; State v. Ellinger, 223 Mont. 349, 725 P.2d 1201 (1986): Reinforce the reduced privacy expectation for exterior vehicle observations accessible to the public (¶ 30).

Miranda and Custodial Interrogation

Miranda v. Arizona, 384 U.S. 436 (1966) and its Montana application: No use of statements stemming from custodial interrogation without warnings. The Court applied the two-step inquiry—custody and interrogation—citing State v. Maile, 2017 MT 154, 388 Mont. 33, 396 P.3d 1270 (¶ 33).
State v. Labbe, 2012 MT 76, 364 Mont. 415, 276 P.3d 848: Six-factor framework to assess whether an interview is custodial: place, time, persons present, gratuitous Miranda warnings, length/mood, and arrest following the interview (¶ 36). Each factor pointed away from custody here (¶ 37).
State v. Peters, 2011 MT 274, 362 Mont. 389, 264 P.3d 1124; Maile: Temporary, public investigatory stops are generally noncustodial (¶ 34).
State v. Allen, 1998 MT 293, 292 Mont. 1, 970 P.2d 81; State v. Hurlbert, 2009 MT 221, 351 Mont. 316, 211 P.3d 869; State v. Bailey, 2021 MT 157, 404 Mont. 384, 489 P.3d 889; State v. Larson, 2010 MT 236, 358 Mont. 156, 243 P.3d 1130: No Miranda requirement during on-the-scene investigation where questioning remains within the scope of escalating suspicions and prior to formal arrest (¶¶ 35–35).
State v. Munson, 2007 MT 222, 339 Mont. 68, 169 P.3d 364: Distinguished. There, officers insisted on continuing in-apartment questioning in the face of nonconsent, creating a coercive, custodial atmosphere. By contrast, Ellis’s encounter was noncoercive and brief (¶¶ 38–39).
Ellinger: Mirrored facts—DUI questioning at residence—no Miranda violation where the defendant remained free to disengage prior to arrest (¶ 40).

Issue Preservation and Appellate Procedure

City of Bozeman v. McCarthy, 2019 MT 209, 397 Mont. 134, 447 P.3d 1048; State v. Akers, 2017 MT 311, 389 Mont. 531, 408 P.3d 142; State v. Homer, 2014 MT 57, 374 Mont. 157, 321 P.3d 77; State v. Lotter, 2013 MT 336, 372 Mont. 445, 313 P.3d 148: Issues not raised in the intermediate appeal from a court of record (justice court) to the district court are generally waived for Supreme Court review (¶¶ 41–44). Ellis’s chain-of-custody/foundation objection to the toxicology report was unpreserved at the Supreme Court level because it was not pursued in the district court appeal.

Sufficiency of the Evidence; Inhalant DUI

State v. Pinder, 2015 MT 157, 379 Mont. 357, 350 P.3d 377: DFE is a “drug” within § 61-8-1002(1)(a), MCA (¶ 45). This establishes the legal basis for DUI convictions based on inhalants.
Standard of review cases: State v. Trujillo, 2008 MT 101; State v. Weitzel, 2006 MT 167; State v. Price, 2002 MT 150; State v. Merrick, 2000 MT 124. The Court reviewed evidence in the light most favorable to the prosecution and asked whether a rational trier of fact could find the elements beyond a reasonable doubt (¶ 15).

2) The Court’s Legal Reasoning

Particularized Suspicion to Investigate DUI

The Court endorsed the officers’ move from crash-response to DUI investigation as justified by accumulating facts: two independent 911 calls, physical signs of a crash, the Jeep’s damage matching roadside damage, Ellis’s dazed condition and watery, bloodshot eyes, and—critically—his admissions that he had purchased and “huffed” Dust-Off and had “passed out” while driving (¶¶ 21, 6–9). Under Gopher and Hulse, this “escalating situation” supplied particularized suspicion, permitting field sobriety testing and further DUI investigation (¶¶ 20–22).

No Unlawful Search or Seizure

Applying Goetz’s privacy framework, the Court concluded Ellis neither manifested an actual expectation of privacy nor had an objectively reasonable expectation in the open, publicly accessible driveway. There were no “No Trespassing” signs, fencing, or other means unmistakably signaling exclusion (contrasting Bullock and Lanchantin), and Ellis did not ask officers to leave (contrasting Smith). Officers merely stood where any member of the public could approach and, from that lawful vantage point, looked into the window of a sedan without entry (¶¶ 29–31). Most importantly, Ellis himself retrieved the Dust-Off can and handed it to law enforcement, eliminating any “search” of the vehicle or “seizure” by officers (¶ 31). The exterior of the Jeep, parked on a public street, likewise offered no reasonable privacy expectation (¶ 30).

No Miranda Violation

The driveway encounter was a temporary, public, and noncoercive investigation: brief questioning in daylight at the edge of the driveway; two officers present; Ellis’s wife nearby; no physical restraint; and a conversational tone (¶ 37). Applying Labbe’s six-factor test, the Court found neither custody nor interrogation in the Miranda sense. It distinguished Munson’s in-home, persistent, nonconsensual engagement. Because the encounter remained within the scope of an escalating investigatory stop and Ellis was not in custody until his arrest, Miranda warnings were not required (¶¶ 34–40).

Issue Preservation

Although Ellis objected at trial to admission of the toxicology report based on foundation/chain-of-custody (the phlebotomist did not testify), he did not raise that ruling in the intermediate appeal to the district court. Under McCarthy and Akers, that omission waived the argument for Supreme Court review (¶¶ 41–44). The Court therefore declined to consider it.

Sufficiency of the Evidence

The State needed to prove that Ellis was in actual physical control of a vehicle on public roads while under the influence of alcohol or “any drug” (§ 61-8-1002(1)(a), MCA). Pinder confirms DFE is a qualifying “drug.” The Court emphasized Ellis’s admissions that he huffed Dust-Off and “passed out,” eyewitness observations, physical crash evidence, and the toxicology detection of DFE. Even though the SFST performance was only “mediocre,” expert testimony explained that DFE impairment is short-lived, which can blunt SFST indicators relative to alcohol. Viewed in the light most favorable to the State, a rational factfinder could find all elements beyond a reasonable doubt (¶¶ 45–47).

3) Impact and Future Significance

Search and Seizure in Residential Settings

Open Driveways: This case reinforces that, absent clear exclusionary measures (e.g., “No Trespassing” signs, fencing, closed gates, explicit direction to leave), a typical suburban driveway offers limited privacy protection under Article II, Section 11. Officers may conduct on-the-scene inquiries and make plain-view observations from such locations without effectuating a “search.”
Voluntary Production of Evidence: When a suspect retrieves and hands over evidence, that act will usually defeat a claim of unlawful search or seizure. Defense claims premised on officer “seizure” of items from a vehicle will face an evidentiary hurdle if the record shows the defendant voluntarily produced the item.
Reconciling Bullock/Smith/Lanchantin: Ellis harmonizes Montana’s robust privacy jurisprudence: strong protections are available when occupants unmistakably assert their privacy (signage, gating, explicit instructions to leave). Where occupants do not do so, or where the driveway is plainly open to public approach, privacy claims will be difficult to sustain.

Miranda in Driveway and Roadside Encounters

Noncustodial Nature of Brief, On-Scene Questioning: The opinion confirms that driveway questioning during an investigatory stop generally tracks roadside-stop principles. Unless officers create a coercive, arrest-like atmosphere, Miranda warnings are not required before asking fact-gathering questions tied to escalating suspicions.
Practical Guidance for Officers: Maintain a noncoercive tone, limit the duration, and keep questioning tethered to the investigation’s evolution. These factors weigh heavily against a finding of custody before arrest.

DUI Enforcement Involving Inhalants

Proof Without Quantification: The Court signaled that DUI convictions premised on inhalants like DFE can rest on circumstantial evidence—admissions, driving behavior (e.g., passing out), crash evidence, and toxicology detection—even if the lab report lacks a numeric impairment threshold.
Short-Lived Impairment: Expert testimony that inhalant impairment dissipates quickly can explain limited SFST clues, reducing the defense’s ability to argue that mediocre SFST performance equals nonimpairment.

Appellate Practice and Preservation

Pipeline Preservation: Practitioners must preserve issues at the intermediate appellate stage (justice/municipal court to district court) or risk waiver at the Supreme Court. Ellis underscores the importance of fully briefing evidentiary objections (e.g., chain of custody) in the district court appeal.

Complex Concepts Simplified

Particularized Suspicion: A lower-than-probable-cause standard requiring specific, articulable facts that, viewed through an officer’s training and experience, reasonably suggest the person is engaged in wrongdoing. It allows brief investigative stops and can expand as new facts emerge.
Escalating Encounter: An investigation that begins for one purpose (e.g., crash response) and lawfully broadens (e.g., to DUI) as new information develops, permitting additional steps like SFSTs.
Expectation of Privacy: To claim a search violation, the person must (1) actually expect privacy and (2) have an expectation that society recognizes as reasonable in the context. Open, publicly accessible spaces like typical suburban driveways often provide limited protection unless exclusion is unmistakably asserted.
Voluntary Production: If a person freely hands over evidence, that is not a government “search” or “seizure” of that item. The person’s consent or voluntary action breaks the causal chain to a suppression remedy.
Custodial Interrogation and Miranda: Miranda warnings are required only if the suspect is in custody (freedom of movement curtailed to the degree of formal arrest) and is being interrogated. Temporary, public, investigatory questioning is typically noncustodial.
DFE (Difluoroethane): A propellant found in some aerosol products (e.g., Dust-Off). Inhaling DFE can rapidly impair motor function and consciousness. Montana law recognizes DFE as a “drug” for DUI purposes.

Conclusion

State v. Ellis is a comprehensive reaffirmation and clarification of Montana doctrine at the intersection of DUI enforcement, privacy in residential settings, and Miranda. The Court:

Approved the expansion of a crash response into a DUI investigation under the “escalating encounter” doctrine based on objective, compounding facts and Ellis’s admissions.
Clarified that open, publicly accessible driveways ordinarily do not confer a reasonable expectation of privacy and that voluntary production of an item to police is not a “search.”
Confirmed that brief, on-scene driveway questioning during an investigatory stop is generally noncustodial, and Miranda advisements are not required until arrest or custody equivalent.
Reinforced Montana’s preservation rules: issues not raised in the intermediate appeal are waived at the Supreme Court.
Affirmed that inhalant-based DUI convictions may rest on circumstantial and toxicology evidence—even absent quantitative impairment metrics—when combined with admissions and driving facts.

For law enforcement, Ellis provides a practical blueprint for handling unfolding DUI investigations in residential environments. For defense counsel, it highlights critical preservation requirements and the importance of asserting residential privacy rights clearly and early. In the broader legal landscape, Ellis thoughtfully harmonizes Montana’s robust privacy jurisprudence with on-the-ground realities of DUI enforcement involving rapidly metabolized inhalants like DFE.