“Evasive-Driving Particularized Suspicion”: The Montana Supreme Court’s Refinement of Reasonable Suspicion in State v. Halie Maria Herzog

1. Introduction

On 17 June 2025 the Supreme Court of Montana decided State v. H. Herzog, 2025 MT 123, affirming a district court’s denial of a suppression motion that challenged a roadside stop which ultimately uncovered methamphetamine. The case arose after Detective Brandon Holzer, a member of the Northwest Drug Task Force, stopped a yellow Volkswagen GTI whose driver exhibited a pattern of apparently evasive maneuvers in rural Lincoln County at 2:30 a.m. The dispositive appellate question was whether the district court relied on clearly erroneous findings of fact when it concluded that Holzer possessed “particularized suspicion” sufficient to justify a temporary investigative stop under Terry v. Ohio and § 46-5-401(1), MCA. The Montana Supreme Court held that it did not, thereby clarifying the scope of lawful investigative detentions premised on a driver’s non-traffic-violation behavior and contextual cues.

2. Summary of the Judgment

• Issue Restated: Did the district court rely upon clearly erroneous factual findings when holding that Detective Holzer had particularized suspicion to stop the Volkswagen?
• Holding: No. The court found substantial evidence supporting the district court’s findings; under the totality of circumstances—evasive route changes, irregular parking in roadside brush, and the observation of a lighter flash at night—Holzer had a particularized, articulable suspicion that the vehicle’s occupants were engaged in drug activity.
• Disposition: District court order denying the motion to suppress AFFIRMED.
• Concurring Opinion (Bidegaray, J.): Joined by Gustafson and McKinnon, emphasized the need for caution in relying on ambiguous conduct (e.g., a “lighter spark”) so as not to erode Article II, § 11 privacy protections.

3. Analytical Commentary

3.1 Precedents Cited and Applied

• Terry v. Ohio, 392 U.S. 1 (1968) – bedrock authority allowing temporary investigative stops on reasonable articulable suspicion.
• State v. Gopher, 193 Mont. 189 (1981) – Montana’s early adoption of the Terry framework.
• State v. Van Kirk, 2001 MT 184 – held that a driver’s attempt to avoid law enforcement may factor into reasonable suspicion.
• State v. Zeimer, 2022 MT 96 – irregular, non-illegal parking can contribute to suspicion of impairment.
• State v. Noli, 2023 MT 84 – articulated the State’s burden to demonstrate particularized suspicion through “specific and articulable objective facts.”
• State v. Hoover, 2017 MT 236, and City of Missoula v. Kroschel, 2018 MT 142 – reviewed for standards on findings of fact and seizure definitions.

The Court weaved these precedents into a cumulative standard: evasive driving (Van Kirk) + irregular parking (Zeimer) + other contextual cues (lighter flash, late-night setting, prior tip regarding same vehicle) suffice, when viewed together, to meet Terry’s “particularized suspicion” threshold.

3.2 The Court’s Legal Reasoning

1. Seizure Timing Immaterial: Whether the “seizure” occurred when Holzer activated grill lights or when he ordered the car to halt was deemed irrelevant because suspicion existed before either moment.
2. Totality-of-Circumstances Analysis: The Court reaffirmed that no single factor is dispositive; instead, objectively odd conduct compiled over roughly one hour created a mosaic of suspicion.
3. Objective Facts Relied Upon:
   • Multiple gas-station entries without fueling.
   • Series of purposeless directional changes and use of back roads slowing eastbound travel.
   • Parking partially concealed in roadside brush at 3 a.m.
   • Observation of a lighter flash in a remote, dark area—an event a trained narcotics officer could reasonably interpret as preparatory to drug use.
4. Clarity of Findings: Each factual finding had record support (testimony, affidavits). Consequently, the “clearly erroneous” standard was not met.

3.3 Potential Impact of the Decision

Herzog subtly but materially recalibrates Montana’s reasonable-suspicion jurisprudence in three ways:

1. Broader Acceptance of Evasive Conduct: The Court gives robust weight to non-statutory traffic behavior (e.g., legal but “odd” turns) as indicative of criminal intent.
2. Contextual Amplification: Otherwise innocuous cues (lighter flick, rural hour, prior BOLO on vehicle) can gain probative force when combined—a principle likely to influence law-enforcement training and lower-court determinations.
3. Cautionary Footnote: The concurrence signals judicial willingness to curb over-extension. Future litigants may cite Justice Bidegaray’s warning to challenge stops premised on de minimis conduct lacking corroboration.

4. Simplifying Key Legal Concepts

• Terry Stop: A brief, warrantless detention for investigative purposes based on reasonable suspicion (less demanding than probable cause).
• Particularized Suspicion: Specific, articulable facts that tie the suspected wrongdoing to the individual stopped, as opposed to a generalized hunch.
• Clearly Erroneous Standard: Appellate deference to a trial court’s fact-finding; reversal only if unsupported by substantial evidence or if the appellate court is left with a firm conviction of error.
• Totality of Circumstances: Holistic review of all facts and reasonable inferences rather than isolation of individual factors.
• Show of Authority: Police conduct—lights, commands, positioning—that would make a reasonable person feel not free to leave, thereby constituting a “seizure.”

5. Conclusion

State v. Herzog stands as a significant clarification of what may constitute “particularized suspicion” in Montana. By validating the investigative stop on cumulative yet individually innocent behaviors, the decision affords law enforcement broader discretion when driver behavior appears calculated to avoid detection. At the same time, the concurrence underscores the continued necessity of tethering suspicion to objective, corroborated facts to prevent erosion of constitutional safeguards. Practitioners should read Herzog as both opportunity and caution: opportunity for prosecutors to defend stops predicated on evasive driving patterns, and caution for defense counsel to scrutinize the quality and quantity of facts officers marshal to justify detention.