Police have long utilized the scent of cannabis as a pretext for searching vehicles during traffic stops in areas where cannabis remains illegal. This practice enables them to confiscate cash and even the vehicles themselves. Once in possession of these assets, law enforcement agencies can employ civil forfeiture, a legal process allowing them to permanently keep the seized property. This practice, akin to legalized highway robbery, operates with court approval.
No arrest or conviction is necessary for civil forfeiture. Once the procedure concludes, participating agencies can divide the proceeds. From 2000 to 2019, state and federal forfeiture revenue in Michigan exceeded $439 million.
Civil forfeiture has become a lucrative enterprise, often initiated by the mere whiff of cannabis. However, Michigan's legalization of recreational cannabis in 2018 has complicated matters for the police. While consuming cannabis in a vehicle remains illegal, possessing it does not, thus eliminating the officers' primary justification for conducting warrantless searches.
The Detroit Police Department struggles to adapt to this new reality. On October 8th, 2020, five Detroit officers on their way to a compliance check stopped when one corporal claimed to smell cannabis emanating from a parked Jeep Cherokee. She then conducted a roadside interrogation of the driver and her passenger, Jeffery Scott Armstrong.
"How long you been smoking weed in the car?" the corporal demanded, according to a transcription of bodycam footage. "I can smell it from outside. Don't act shocked. I can smell it."
Prior to 2018, such an encounter would have been standard procedure. However, the mere smell of cannabis no longer constitutes a crime. The corporal should have continued on her way, but she opted to stop and search the vehicle, infringing on the occupants' Fourth Amendment rights against unreasonable search and seizure.
The officers discovered a firearm under Armstrong's seat and arrested him for being a felon in possession of a firearm, although no cannabis was found. This outcome is unsurprising, as cannabis odor can linger long after its legal use or exposure to others smoking it. Moreover, officers can be mistaken or dishonest. A study in Philadelphia revealed that contraband was found in fewer than 10% of the 3,300 cannabis odor-based vehicle searches conducted by police.
Despite their poor success rate, police remain confident in their olfactory abilities. In 2019, three Indiana officers even testified that they detected less than one gram of unlit cannabis in a closed container from a moving car over 100 yards away, despite a breeze cutting across traffic.
Drug-sniffing dogs also have a high error rate, often failing to differentiate between legal hemp and cannabis. These canines cannot specify whether they detect cannabis or other narcotics like cocaine, rendering them ineffective in states like Michigan where cannabis is legal.
Both human and canine cannabis sniffers need to adapt to the changing legal landscape. Armstrong's case provided Michigan courts with an opportunity to offer clarity when he filed a motion to suppress evidence from the 2020 search. A trial court granted his motion, and the Michigan Court of Appeals upheld the decision in 2022. Dissatisfied, the state petitioned the Michigan Supreme Court, which agreed to hear the case.
Our public interest law firm, the Institute for Justice, alongside the Cato Institute, submitted a friend-of-the-court brief supporting Armstrong. Our argument is straightforward: If a substance is legal, its odor should not constitute probable cause for a search.
Armstrong's case highlights the need for thorough judicial review of probable cause determinations made by officers in the field. Civil forfeiture can bias these decisions, fostering aggressive policing due to financial incentives.
Although Armstrong did not lose cash or his vehicle, many others are not as fortunate. Innocent property owners often suffer when officers exploit the scent of cannabis as a pretext for warrantless searches.
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