The “Perry Rule” – Odor-Based Probable Cause Survives Marijuana Decriminalization in New Mexico

Introduction

The Supreme Court of New Mexico’s decision in State v. Perry, No. S-1-SC-40187 (July 9, 2025) confronts a narrow but consequential question: does the long-standing doctrine that “the smell of marijuana alone provides probable cause for a warrantless vehicle search” remain valid during the brief window (2019-2021) when New Mexico had decriminalised— but not yet legalised—possession of small amounts of cannabis?

The Court answers “Yes”, thereby creating what practitioners will now call the Perry Rule: Decriminalisation does not, without more, extinguish probable cause flowing from the odor of contraband; until full legalisation, marijuana remained “contraband” and its smell alone justified a vehicle search.

The ruling affects dozens of pending suppression disputes from the 2019-2021 “in-between” period, clarifies analytic methodology when legislation downgrades a crime to a civil infraction, and signals how New Mexico may treat analogous scenarios involving other substances (e-g., psilocybin) should partial reforms emerge.

Summary of the Judgment

• A police officer stopped Sandra Perry for traffic violations in November 2020.
• The officer smelled marijuana emanating from the truck and, relying chiefly on that odor, obtained Perry’s consent to search. The search uncovered a non-criminal amount of marijuana, methamphetamine, and paraphernalia.
• Perry moved to suppress, arguing that after decriminalisation the odor no longer created probable cause to think a crime was afoot.
• The District Court denied suppression; the Court of Appeals certified the discrete legal question to the Supreme Court.
• The Supreme Court held that State v. Capps (1982)—odor alone equals probable cause— survived the 2019 decriminalisation amendments.
• Key rationales: (1) decriminalisation ≠ legalisation; possession of any amount remained illegal and marijuana thus remained contraband; (2) probable cause may rest on reasonable grounds to believe contraband or evidence of a violation is present, not solely a criminal offence; (3) persuasive alignment with Maryland’s Robinson decision; and (4) Nyce’s treatment of “ordinary, innocent facts” is inapposite because marijuana possession was not innocent.
• Certified question answered in the affirmative; case remanded to the Court of Appeals for full suppression analysis (state constitutional issues left open).

Analysis

3.1 Precedents Cited and Their Influence

State v. Capps, 97 N.M. 453 (1982)
– Established New Mexico’s odor-alone doctrine for vehicle searches.
– Perry reaffirms Capps, extending its vitality into the decriminalised era.
State v. Nyce, 139 N.M. 647 (2006)
– Held that suspicion of non-criminal, innocent acts cannot create probable cause.
– Perry distinguishes Nyce: cannabis possession in 2020 was not an innocent act; odor is inherently incriminating.
State v. Williamson, 146 N.M. 488 (2009) & State v. Ochoa, 135 N.M. 781 (2004)
– Frame probable cause in terms of “contraband or evidence of a crime.”
– Court leverages this disjunctive phrasing to reason that civil-penalty contraband still suffices.
Robinson v. State, 152 A.3d 661 (Md. 2017)
– Comprehensive treatment of odor-based probable cause after Maryland’s partial decriminalisation.
– Adopted verbatim by Perry for its “decriminalisation is not legalisation” logic and dictionary-based definition of “contraband.”
Secondary citations: Sanchez (2015-NMCA-084) and Anderson (1988-NMCA-033) used by the defendant; Court finds them inapposite.

3.2 The Court’s Legal Reasoning

Statutory Landscape – 2019 amendment reclassified ≤½-oz possession as a civil infraction. The 2021 Cannabis Regulation Act later fully legalised adult possession, but Perry’s stop occurred in the interim.
Contraband vs. Crime – The Court decouples “illegality” from “criminality.” Even where conduct is non-criminal, the item can remain legally forbidden to possess, ergo “contraband.”
Probable Cause Standard – Citing Nyce & Williamson, the Court reiterates that probable cause asks whether officers reasonably believe they will uncover evidence of wrongdoing or contraband, not necessarily a jailable offence.
Analogy to Robinson – By adopting Maryland’s reasoning, the Court fortifies its stance with an external persuasive authority confronting identical statutory changes.
Certification Posture – The Court confines itself to the certified federal issue, refusing to expand into broader state-constitutional proportionality—leaving the Court of Appeals leeway.

3.3 Potential Impact of the Decision

Window Cases (2019-2021) – Suppression motions premised on the “odor-alone invalid” theory are now foreclosed; convictions based on odor-originated searches remain intact.
Guidance for Partial Decriminalisation of Other Substances – The reasoning signals that until the Legislature fully normalises possession, odor or other obvious indicators of possession will suffice for probable cause.
Federal-State Harmony – Retains parallelism with numerous federal circuits that still treat marijuana odor as PC notwithstanding varied state reforms.
Unanswered Questions – After 2021 full legalisation, odor-alone PC almost certainly fails; Perry does not speak to the post-legalisation era. Courts will need new metrics (e.g., impairment, quantity, packaging).
Civil Liberties Litigation – Encourages defendants to shift focus from Fourth-Amendment scent arguments to state-law limitations on search scope or voluntariness of consent.

Complex Concepts Simplified

Decriminalisation vs. Legalisation
– Decriminalisation: Conduct is still illegal but punishable only by a civil fine (no jail, no criminal record).
– Legalisation: Conduct becomes lawful under specified conditions.
Contraband
– Any item whose mere possession is forbidden by law. Contraband need not relate to a criminal offence (example: untaxed cigarettes, some fireworks).
Probable Cause (PC)
– A fluid, commonsense standard demanding “reasonable grounds” to think evidence of wrongdoing or contraband is present. Requires more than a hunch, less than proof beyond a reasonable doubt.
Certified Question
– A procedure where an intermediate appellate court asks a state’s highest court to resolve a determinative legal issue on which binding precedent is uncertain.
Odor-Based PC
– Doctrine that certain smells (marijuana, alcohol, chemicals for explosives) can, standing alone, meet the PC threshold for searching vehicles because scents indicate the likely presence of contraband.

Conclusion

State v. Perry reaffirms New Mexico’s commitment to the odor-based probable cause doctrine during periods where an item remains contraband notwithstanding downgrading of criminal penalties. By adopting the “contraband–evidence” framework and the persuasive reasoning of Maryland’s Robinson, the Court solidifies analytical tools for future statutory transitions, clarifies the limits of Nyce, and underscores a judiciary reluctant to dilute long-standing search principles absent explicit legislative or constitutional command.

Practitioners must note: (1) For incidents between July 1, 2019 and June 28, 2021, marijuana odor still justifies vehicular searches; (2) After full legalisation, new probable-cause paradigms will be required; (3) Challenges may pivot to state constitutional grounds or the voluntariness of consent rather than the existence of probable cause itself.

Ultimately, the “Perry Rule” serves as a cautionary tale: incremental legislative reforms create liminal periods in which traditional search doctrines can and often do endure. Courts, law enforcement, and defendants alike must tread mindfully through these transitional landscapes.