The North Carolina Supreme Court is preparing to hear arguments in a case that could fundamentally reshape how law enforcement conducts searches based on the smell of cannabis in the state. With hemp legal in the state, the question before the justices centers on whether officers can still claim they smell the difference between legal hemp and illegal marijuana—a distinction which is scientifically impossible.
The case shows growing tension between cannabis prohibition and the reality of hemp legalization. Hemp and marijuana are the same plant, Cannabis sativa, with identical appearance and aroma.
The only difference lies in their THC content: hemp contains less than 0.3% delta-9-THC as defined by the 2018 Farm Bill, while marijuana exceeds that threshold.
Yet North Carolina courts have continued allowing police to use “marijuana odor” as probable cause for searches, even when the substance in question could be perfectly legal hemp.
The Science Behind the Smell
Distinguishing between hemp and marijuana by smell alone is impossible. The aromatic compounds responsible for cannabis’s distinctive scent—called terpenes—are identical in both hemp and marijuana plants. Some of these terpenes include myrcene, limonene, and pinene, which create the characteristic earthy, citrusy, or piney aromas that cannabis users know well.
Cannabis researchers have extensively studied terpene profiles across different cannabis varieties, finding that hemp and marijuana can share identical aromatic signatures. Some hemp strains actually produce stronger odors than certain marijuana varieties, making smell-based identification even less reliable.
The North Carolina State Bureau of Investigation recognized this scientific reality in a 2019 memo, warning lawmakers that hemp legalization would make smell-based searches problematic. The memo stated that “marijuana will be legalized in NC because law enforcement cannot distinguish between hemp and marijuana and prosecutors could not prove the difference in court.”
Three cases now before the Supreme Court—State v. Schiene, State v. Dobson, and State v. Rowdy—challenge the continued use of smell as probable cause. These cases argue that because hemp and marijuana are indistinguishable by scent, officers cannot reasonably claim to smell specifically illegal marijuana.
The Court of Appeals has consistently ruled in favor of law enforcement, maintaining that probable cause requires only that an officer reasonably believes they smell marijuana, regardless of whether such identification is actually possible. This standard has created what critics call a legal fiction—allowing searches based on a sensory distinction that doesn’t exist.
The Testing Gap
North Carolina‘s legal system faces a significant obstacle: the State Crime Lab cannot definitively distinguish between hemp and marijuana, reports The Assembly. The lab can detect THC presence but cannot measure precise concentrations needed to determine legality. Local law enforcement agencies lack field testing capabilities entirely.
This testing gap creates an absurd situation where people can be arrested and charged based on substances that may be completely legal. The burden then falls on defendants to prove their innocence, reversing the traditional presumption of innocence until proven guilty.
Rod Kight, a hemp industry attorney, via the Assembly called the state’s failure to upgrade testing capabilities “absurd” after nearly a decade of hemp legalization. The General Assembly has not provided funding for equipment that could resolve these identification issues, leaving the criminal justice system to operate on scientifically unsupported assumptions.
Civil rights advocates argue that smell-based searches violate Fourth Amendment protections against unreasonable search and seizure. When a legal substance is indistinguishable from an illegal one, using that substance’s alleged presence to justify searches effectively criminalizes lawful behavior.
Law Enforcement Perspective
Police organizations maintain that marijuana odor remains valid probable cause, even acknowledging that hemp and marijuana smell identical. The North Carolina Conference of District Attorneys, Association of Chiefs of Police, and Sheriffs’ Association filed joint briefs defending current practices.
Attorney for police organizations, argue that eliminating smell-based searches would prevent officers from investigating marijuana odor “even if other facts supporting probable cause were present.” They contend that smokable hemp remains a “niche market” and officers are usually correct when they believe they smell marijuana. However, if this claim is to hold up in a court of law, there should be a requirement for concrete proof.
Laboratory analysis remains the only reliable method for determining THC content. High-pressure liquid chromatography and gas chromatography can precisely measure cannabinoid concentrations, providing definitive legal classifications. These testing methods are standard in states with cannabis programs but remain unavailable for North Carolina law enforcement.
The absence of proper testing infrastructure forces the criminal justice system to rely on subjective human perception for objective legal determinations. This approach would be unacceptable in any other area of law requiring scientific precision.
Economic Impact on Defendants
Beyond constitutional concerns, smell-based searches impose significant economic burdens on defendants. Even when charges are eventually dismissed, people must hire attorneys, take time off work, arrange childcare for court appearances, and endure months of legal uncertainty.
These costs disproportionately affect low-income communities, who may lack resources for adequate legal representation. Many defendants accept plea bargains rather than fight charges, even when they possessed legal hemp products, because the cost of mounting a defense exceeds the penalties of conviction.
The economic inefficiency extends to the broader criminal justice system. Courts, prosecutors, and police waste resources prosecuting cases involving legal substances, diverting attention from genuine public safety concerns.
Looking Forward
The North Carolina Supreme Court’s decision in these cases could establish important precedent for cannabis-related searches nationwide. Other states grappling with similar hemp legalization issues are watching closely for guidance on balancing law enforcement needs with constitutional protections.
If the court rules that smell alone cannot establish probable cause, law enforcement agencies will need to develop new investigative techniques. This might include investing in proper field testing equipment, seeking additional evidence beyond smell, or focusing enforcement efforts on more serious drug crimes.
Alternatively, if the court maintains current practices, civil rights advocates predict increased federal litigation challenging North Carolina’s approach. The fundamental tension between legal hemp and prohibited marijuana will continue generating constitutional conflicts until resolved through legislative action or higher court intervention.
The cases before the Supreme Court represent more than technical legal questions about probable cause standards. They embody broader debates about criminal justice reform, racial equity, scientific evidence in legal proceedings, and the evolution of cannabis policy in America.
As North Carolina’s highest court prepares to rule, the decision will likely influence cannabis law enforcement across the region. The justices must balance public safety concerns with constitutional protections, scientific evidence with legal precedent, and traditional law enforcement practices with evolving social attitudes toward cannabis.
The outcome will determine whether North Carolina continues allowing searches based on sensory distinctions that science says don’t exist, or whether the state will require more rigorous standards for criminal investigations in the hemp era.
