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Montana Supreme Court: Odor of Marijuana by Itself Insufficient to Prolong Traffic Stop

by Anthony W. Accurso

The Supreme Court of Montana ruled a state trooper impermissibly extended a traffic stop to investigate a drug possession based solely on the odor of marijuana and undeveloped hunches.

William James Harning was driving a truck full of ceramics to an art show around 10:00 a.m. on March 1st, 2018, when he was pulled over for speeding — 74 mph in a 65-mph zone — near Billings, Montana, by Trooper Tyler DiGiovanna. As the trooper approached the truck, Harning rolled his window down about four inches. DiGiovanna asked him to roll it down completely, and Harning refused, saying he did not feel comfortable doing so.

Through the window, DiGiovanna smelled the odor of marijuana and began asking questions about Harning’s marijuana use. The trooper would later describe Harning’s responses by saying, “[h]e appeared as though he was trying to pick his words carefully, which is not normal of someone being honest.” Harning conveyed that he had smoked marijuana when he had stopped in Big Timber (80 miles away) but that he did not smoke in his vehicle — nor did he have any marijuana on his person.

Because Harning admitted to recently smoking marijuana, DiGiovanna informed Harning that he would perform a field sobriety test to assess whether he was driving under the influence (“DUI”). DiGiovanna performed a pat-search of Harning and located no contraband. Harning then completed the sobriety test in a way that demonstrated he was not intoxicated.

Though DiGiovanna would later testify that it was prior to the field sobriety test that he decided to perform a narcotics investigation, it was only after Harning passed the test that the trooper told him the truck would be detained pending a drug-detection dog sniff of the vehicle.

Another 17 minutes passed as the pair waited for the canine handler to arrive. The dog alerted on Harning’s truck, and a subsequent search of it revealed a glass marijuana pipe and a grinder. For these items and the residue on them, Harning was charged with criminal possession of marijuana and drug paraphernalia.

Harning filed a pretrial motion to suppress evidence obtained from the search of his vehicle on the ground that the trooper impermissibly extended the stop after completing the DUI investigation. The Justice Court denied the motion, finding the trooper had probable cause for the stop and reasonable suspicion to justify its transformation into a narcotics investigation.

Harning pleaded guilty to both counts but preserved his right to appeal the denial of the suppression motion.

The Court began its analysis by noting that both the Fourth Amendment to the U.S. Constitution and Article II, Section 11, of the Montana Constitution protect persons from unreasonable searches and seizures — including short investigatory stops like traffic stops. State v. Wilson, 430 P.3d 77 (Mont. 2018).

To initiate a lawful traffic stop, police must have a particularized suspicion that the occupant of the vehicle is or has been engaged in unlawful behavior. § 46-5-401(1), MCA. A traffic stop may not last any longer than necessary to resolve the initial purpose of the stop. § 46-5-403, MCA. Traffic stops “may be prolonged, and the scope of the investigation enlarged, provided the scope of the investigation remains within the limits created by the facts and suspicions from which they arose.” State v. Estes, 403 P.3d 1249 (Mont. 2017).

The parties agreed that it was reasonable for the trooper to initiate the traffic stop based on Harning exceeding the posted speed limit. They also agreed that the stop properly ripened into a DUI investigation.

The State claimed that Harning’s “evasive behavior,” the odor of marijuana, and Harning’s admission to having smoked earlier in the day were sufficient to give the trooper particularized suspicion that Harning possessed drugs and thereby justifying the dog sniff and subsequent search of his vehicle.

But the Court disagreed. To lawfully prolong the traffic stop and to conduct a canine sniff of the vehicle, the trooper was required to have particularized suspicion that there were drugs in the vehicle, the Court explained.

“A canine sniff of a vehicle constitutes a search under Article 2, Sections 10 and 11, of the Montana Constitution.” State v. Tackitt. 67 P.3d 295 (Mont. 2003). Consequently, police must have a particularized suspicion of wrongdoing to conduct a canine search of a vehicle. Id. The Court stated that particularized suspicion “requires objective data from which an experienced officer can make certain inferences and a resulting suspicion that the occupant of the vehicle is or has been engaged in wrongdoing.” Estes. Although police need not be certain or even correct that a person is engaged in criminal activity, “particularized suspicion requires more than mere generalized suspicion or an undeveloped hunch of criminal activity,” according to the Court. Wilson.

“[O]fficers may rely on a distinctive odor as a physical fact indicative of a possible crime; but its presence alone does not strip an individual of constitutional guarantees against unreasonable search.” Taylor v. United States, 286 U.S. 1 (1932) (finding the odor of whiskey during the Prohibition Era insufficient to justify a warrantless search).

The Court concluded that DiGiovanna lacked particularized suspicion to extend the traffic stop and DUI stop to conduct a drug investigation. It stated that DiGiovanna’s testimony that he decided to conduct a drug investigation after citing Harning for speeding guides its analysis. The Court stated that other than declining to roll his window down more than a few inches and allegedly “hemm[ing] and haw[ing],” DiGiovanna “did not articulate objective data indicating Harning’s vehicle likely contained drugs” at that point in time during the traffic stop.

The Court explained that “Trooper DiGiovanna never testified to any facts that were specific and particularized to Harning’s vehicle which would support a suspicion the vehicle itself contained illegal drugs.” In fact, Harning admitted to smoking approximately 80 miles from the location of the traffic stop — but not in his truck — and it is known that the smell of marijuana does not dissipate quickly. See State v. Schoendaller, 578 P.2d 730 (Mont. 1978) (“the mere odor of marijuana might linger in an automobile for more than a day”).

The Court further explained: “Importantly, although Harning was subjected to a traffic stop and DUI investigation, he retained a right of privacy in his vehicle which, absent particularized and articulable facts relating to his vehicle, could not be violated.”

Furthermore, the Court did not credit DiGiovanna’s description of Harning’s conduct. It said he “failed to articulate, beyond a circular definition of ‘just subtle kind of things’ about Harning’s ‘evasive’ behavior, how he came to suspect Harning had drugs in his vehicle.” Thus, the Court concluded that once DiGiovanna determined Harning was not impaired, “the stop should have terminated … [because] Trooper DiGiovanna possessed only an undeveloped generalized suspicion, based off the smell of marijuana, that Harning’s vehicle may have contained drugs.”

Accordingly, the Court reversed Harning’s conviction and remanded for proceedings consistent with its opinion. See State v. Harning, 507 P.3d 145 (Mont. 2022). 

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