Supreme Court of Michigan Finds the Odor of Marijuana, by Itself, Does Not Support a Warrantless Search for Illegal Contraband

In 2018, Michigan passed the Michigan Regulation and Taxation of Marihuana Act (MRTMA), which legalized recreational marijuana for people who are at least 21 years old. So, in the wake of MRTMA, does the odor of marijuana, by itself, support a warrantless search for illegal contraband? That was the question of first impression recently answered by the Supreme Court of Michigan in its recent opinion in People v. Armstrong, 2025 WL 994370 (Mich. 2025).

In Armstrong,

several police officers were conducting parole compliance checks in the city of Detroit. During those checks, Corporal Treva Eaton observed a Jeep Cherokee parked on the side of the street and allegedly smelled the scent of burnt marijuana coming from the vehicle as she drove by. Corporal Eaton parked her patrol vehicle and turned on her body camera. The video shows several uniformed police officers surround the vehicle and make contact with the vehicle's occupants. Defendant, Jeffery Armstrong, was seated in the front passenger's seat and a woman was seated in the driver's seat.

Corporal Eaton approached the passenger side and began speaking with defendant. She asked defendant which house he lived in. Defendant said that he was just visiting the area. Corporal Eaton asked defendant how long he had “been smoking weed in the car.” Defendant denied smoking marijuana in the car, stating that he had just got into the vehicle. Corporal Eaton also asked the driver if she was smoking marijuana in the car, which the driver denied. Corporal Eaton reiterated that she could smell marijuana. She asked defendant and the driver if they knew the man who was the subject of the officers’ compliance check. After they indicated they did not know the man, Corporal Eaton asked defendant where he lived, and defendant pointed down the street. At that point, Corporal Eaton asked defendant to step out of the vehicle. She patted him down and handcuffed him. Another police officer, Officer Hayley Genaw, stepped between the open door and the passenger compartment and looked inside the vehicle. According to her later written report, Officer Genaw recorded that she observed a black handgun under the front passenger seat as Corporal Eaton was removing defendant from the vehicle. Based on the body camera footage, however, the trial court determined that “the firearm was not visible until Armstrong had already been removed from the vehicle” and that Officer Genaw did not discover the gun until “she searched the vehicle, and under the front passenger seat.” (Emphasis added.)

In addressing Armstrong's ensuing appeal, the Supreme Court of Michigan reversed its prior precedent in People v Kazmierczak,  605 N.W.2d 667 (Mich. 2000), which had held that the odor of marijuana, by itself, supports a warrantless search for illegal contraband. According to the court in Armstrong,

A sea change regarding the legality of marijuana occurred in 2018 when Michigan voters passed the MRTMA. The general intent of the MRTMA is to decriminalize the use and possession of marijuana in the state of Michigan....Certain conduct is still prohibited, however, including “being in physical control of any motor vehicle...while under the influence of marihuana,” MCL 333.27954(1)(a), “consuming marihuana in a public place,” MCL 333.27954(1)(e), and “consuming marihuana while...being in physical control of any motor vehicle...or smoking marihuana within the passenger area of a vehicle upon a public way,” MCL 333.27954(1)(g).

This appeal is the first time that this Court has had the opportunity to consider the continuing viability of the Kazmierczak rule following the passage of the MRTMA. We agree with the Court of Appeals that in light of the voters’ intent to legalize marijuana usage and possession, the smell of marijuana, standing alone, no longer constitutes probable cause sufficient to support a search for contraband.

As noted, when Kazmierczak was decided, all possession, use, and transportation of marijuana was a crime in Michigan. Accordingly, the smell of marijuana indicated that the criminal possession, use, or transportation of marijuana had occurred at some point. In other words, simply smelling marijuana indicated a “substantial chance of criminal activity....”...In that context, a rule like the one announced in Kazmierczak was reasonable. But now that marijuana possession and use is generally legal, the odor of marijuana does not on its own supply a substantial basis for inferring a fair probability that contraband or evidence of illegal activity will be found in a particular place....Instead, post-MRTMA, the smell of marijuana might just as likely indicate that the person is in possession of a legal amount of marijuana, recently used marijuana legally, or was simply in the presence of someone else who used marijuana.

However, even under the MRTMA, marijuana possession and use are not legal for all people under all circumstances. For example, operating a motor vehicle under the influence of marijuana remains a crime, see MCL 333.27954(1) and MCL 257.625(1), and smoking marijuana in public is a civil infraction, MCL 333.27965(1). Thus, although the smell of marijuana is no longer sufficiently indicative of the presence of contraband or illegal activity, that does not mean that the smell of marijuana is irrelevant to developing probable cause concerning illegal activity....This general principle has already been recognized in cases such as Anthony and Moorman that considered the Kazmierczak rule after the MMMA was enacted. That is, these decisions already recognized that, given the legalization of marijuana under some circumstances, something more than the smell of marijuana alone is needed to support probable cause. This need for “something more” is now even more pronounced in light of the passage of the MRTMA.

We, therefore, agree with the Court of Appeals that “ ‘the smell of marijuana may be a factor, but not a stand-alone one, in determining whether the totality of the circumstances established probable cause to permit a police officer to conduct a warrantless search of a vehicle’ ....”...Other relevant inculpatory facts might include, for example, an officer's observation of evidence suggesting intoxication or the presence of smoke. This rule is consistent with rules crafted in other states where marijuana has been decriminalized or legalized....More importantly, this rule is consistent with the Fourth Amendment principle that “[w]here the standard is probable cause, a search or seizure of a person must be supported by probable cause particularized with respect to that person.”...The presence of other inculpatory facts that suggest not only the illegal use of marijuana but, importantly, the where, when, and who of that use, is critical to determining whether probable cause exists to support a search. We, therefore, hold that Kazmierczak’s rule that the smell of marijuana, standing alone, is sufficient to support a finding of probable cause under the automobile exception to the warrant requirement is no longer viable in light of the enactment of the MRTMA. As applied in the present case, because the alleged basis for the officers’ search of the automobile was the smell of marijuana standing alone, the search was not constitutional under the automobile exception to the warrant requirement.

-CM