People v Wilkins: Automobile-Exception Probable Cause Must Target Evidence of a Crime, Not a Civil Infraction

Introduction

In People of Michigan v. Freddie Wilkins, III (Mich Sup Ct, July 22, 2026), the Michigan Supreme Court confronted a post-legalization search-and-seizure problem: whether the Fourth Amendment’s automobile exception permits a warrantless vehicle search when police have probable cause only to believe a civil infraction occurred—here, underage possession of a small amount of marijuana under the Michigan Regulation and Taxation of Marihuana Act (MRTMA), MCL 333.27951 et seq.

A trooper stopped Wilkins for speeding, smelled marijuana, learned both occupants were under 21, received an admission from the passenger that she had “shake,” and then searched the vehicle—finding a firearm (but no marijuana). Wilkins moved to suppress, arguing the search violated the Fourth Amendment. The circuit court denied suppression; the Court of Appeals affirmed; and the Michigan Supreme Court reversed.

The central issue became: Does probable cause to believe only a civil marijuana infraction occurred justify a warrantless automobile search?

Summary of the Opinion

The Court held the search unlawful. It announced a clear rule for Michigan: the automobile exception requires probable cause to believe that contraband or evidence of a crime will be found; probable cause that a person is responsible only for a civil infraction is insufficient. Because MRTMA makes first/second underage possession of ≤ 2.5 ounces a civil infraction, MCL 333.27965(3)(a) and (b), the trooper needed probable cause to believe a criminal amount of marijuana (or evidence of another crime) was present.

The Court further held that the smell of marijuana does not per se provide probable cause regarding possession of a criminal amount, and on these facts (odor + “shake” admission + no observable intoxication or smoking + no marijuana in plain view), probable cause of a criminal marijuana offense was not established.

Result: the Court of Appeals was reversed and the case remanded for further proceedings.

Analysis

Precedents Cited

The opinion is precedent-heavy, using historical Fourth Amendment cases to define the outer boundary of exceptions and modern cases to anchor the automobile exception’s elements.

  • People v Duff (514 Mich 617; 22 NW3d 476 (2024)) supplied the standard of review: factual findings reviewed for clear error; constitutional questions reviewed de novo.
  • People v Armstrong (___ Mich ___ (April 2, 2025)) framed marijuana odor after MRTMA: the smell of marijuana alone is not sufficient for probable cause. Wilkins extends the post-MRTMA logic by adding a new constraint: even if odor supports probable cause of marijuana presence, that probable cause must still be tied to criminal contraband/evidence to trigger the automobile exception.
  • People v Kazmierczak (461 Mich 411; 605 NW2d 667 (2000)) appeared primarily as an articulation of probable cause (fair probability that contraband or evidence of a crime will be found), while recognizing Armstrong’s limitation of the former “odor-alone” rule.
  • California v Carney (471 US 386 (1985)), Chambers v Maroney (399 US 42 (1970)), United States v Ross (456 US 798 (1982)), California v Acevedo (500 US 565 (1991)), Pennsylvania v Labron (518 US 938 (1996)), and Illinois v Gates (462 US 213 (1983)) were used to restate the automobile exception’s traditional justification (mobility + reduced vehicle privacy expectations) and scope (containers included), but always coupled to “contraband or evidence of a crime.”
  • Carroll v United States (267 US 132 (1925))—the automobile-exception origin case—was examined at length to argue that “contraband” in the automobile context historically meant goods whose possession/transport violated criminal law, and that Carroll did not decide searches based solely on civil wrongdoing.
  • The Court reinforced the “jealously and carefully drawn” nature of exceptions with Jones v United States (357 US 493 (1958)), and exclusionary principles with Wong Sun v United States (371 US 471 (1963)) and United States v Calandra (414 US 338 (1974)).
  • For Fourth Amendment history and the anti-general-warrant impulse, the Court relied on Boyd v United States (116 US 616 (1886)), Weeks v United States (232 US 383 (1914)), and Md Penitentiary Warden v Hayden (387 US 294 (1967)). These cases were not mere backdrop; they supported the Court’s normative claim that minor offenses should not readily justify intrusive, suspicion-driven searches.
  • The Court used “reasonableness balancing” authority—especially Delaware v Prouse (440 US 648 (1979)) and Lange v California (594 US 295 (2021))—to tie the automobile exception to proportionality: the smaller the governmental interest (civil infraction), the harder it is to justify bypassing a warrant.
  • Civil-versus-criminal proportionality also drew support from Welsh v Wisconsin (466 US 740 (1984)) (limits on warrantless home entry for lesser offenses) and state cases State v Holmes (569 NW2d 181 (Minn, 1997)) and State v Duncan (146 Wash 2d 166 (2002)) (skepticism of using Terry-type intrusion for civil infractions).
  • Michigan’s own privacy tradition was invoked via People v Marxhausen (204 Mich 559; 171 NW 557 (1919)).
  • The Court discussed Massachusetts marijuana cases—Commonwealth v Cruz (459 Mass 459 (2011)), Commonwealth v Rodriguez (472 Mass 767 (2015)), Commonwealth v Overmyer (469 Mass 16 (2014)), Commonwealth v Daniel (464 Mass 746 (2013)), and Commonwealth v Sheridan (470 Mass 752 (2015))—to support the proposition that odor and other ambiguous cues do not reliably map onto “criminal amount,” and thus cannot mechanically produce automobile-exception probable cause.
  • The dissent’s anchor precedent, Florida v White (526 US 559 (1999)), was distinguished by the majority as a forfeiture-and-seizure case tied to felony instrumentalities and public-place seizure principles, not a general license to treat civilly regulated items as “contraband” for automobile searches.
  • The Court noted (without deciding) related stop-prolongation concerns under Rodriguez v United States (575 US 348 (2015)) and recorded the prosecution’s concession that the person-search exceeded Terry v Ohio (392 US 1 (1968)).

Legal Reasoning

The opinion’s reasoning proceeds in three moves: (1) define the automobile exception as historically and doctrinally crime-focused, (2) treat civil infractions—especially MRTMA’s underage possession infraction—as reflecting a reduced governmental interest, and (3) require probable cause of a crime (or criminal contraband) to justify a warrantless automobile search.

1) Automobile exception = probable cause of “contraband or evidence of a crime”

The Court emphasized that Michigan and federal cases repeatedly formulate the automobile exception as requiring probable cause that “contraband or evidence of a crime” will be found (e.g., People v Keller quoting Illinois v Gates; and the Court’s own language in People v Armstrong). That formulation mattered because it allowed the Court to separate “violation of law” from “crime,” rejecting the notion that any enforceable civil violation can justify a warrantless evidentiary search of the entire vehicle.

2) “Contraband” does not automatically include civil-only prohibited substances

The Court confronted the prosecution’s attempt to broaden “contraband” to include marijuana possessed by under-21 persons even when the possession is only a civil infraction. It rejected definitional shortcuts (including a broad Black’s Law Dictionary sense of “unlawful”) and instead insisted that exceptions to the warrant requirement are not expanded by ambiguity. Citing People v Reed, it placed the burden on the state to show the search falls within an established exception, not on the defendant to show the exception should be narrowed.

The Court’s historical treatment of Carroll v United States is the doctrinal keystone: it read Carroll’s “contraband goods” concept as emerging from criminal prohibitions (Prohibition-era liquor and customs-type criminal enforcement). It then paired that history with a modern proportionality theme: absent criminality, warrantless automobile searches risk recreating the very general-warrant abuses the Fourth Amendment was designed to prevent (Boyd v United States; Weeks v United States).

3) MRTMA’s civil-infraction design signals diminished enforcement interest

Under MRTMA, underage possession of ≤ 2.5 ounces is a civil infraction for first/second violations, MCL 333.27965(3), while larger amounts carry criminal penalties, MCL 333.27965(4). The Court treated this statutory structure as an expression of voter intent to decriminalize low-level marijuana conduct (People v Armstrong) and to deprioritize punitive enforcement.

That reduced governmental interest, the Court held, cannot justify the heightened intrusion of a warrantless search under the automobile exception—particularly where traffic stops are frequent and commonly triggered by civil infractions, creating an unacceptable risk that “nearly every traffic stop” becomes a search.

Application to the facts: odor + “shake” = civil probable cause, not criminal probable cause

Because the civil/criminal line turns on quantity, the Court required probable cause of a “criminal amount.” It held marijuana odor is too subjective and environmentally contingent to support an inference of criminal quantity (relying on Commonwealth v Overmyer and the Court’s own observations in People v Armstrong). The passenger’s “shake” admission suggested only a small quantity and did not supply a “substantial basis” to believe a criminal amount was present.

Impact

1) A new Michigan rule limiting automobile-exception searches. After Wilkins, Michigan officers may not justify a warrantless vehicle search under the automobile exception on probable cause that the occupants committed only a civil infraction. In marijuana contexts, probable cause must point to (a) a criminal quantity, or (b) some other crime (e.g., OWI-drug or distribution).

2) Marijuana-odor jurisprudence becomes quantity-sensitive. People v Armstrong already rejected an odor-alone rule. Wilkins goes further: even when odor plus other facts indicates underage possession, that may still be only civil-level probable cause and thus insufficient for an automobile search.

3) Litigation focus will shift to “criminality indicators.” Future suppression disputes will likely turn on whether officers can articulate objective facts suggesting criminal quantity or other criminal conduct: visible bulk packaging, scale/ledger, admissions of sales, plain-view quantities, impairment cues, recent smoking evidence, or other corroboration.

4) Potential ripple beyond marijuana. The Court’s reasoning is not marijuana-exclusive: it is a broader Fourth Amendment statement about civil infractions and warrantless automobile searches. That logic may invite challenges where police rely on civil-only regulatory violations as a pretext for comprehensive searches.

5) State constitutional development remains open. Justice WELCH’s concurrence urged deciding the case under Const 1963, art 1, § 11, noting the absence of directly applicable federal precedent in a landscape where marijuana remains federally illegal. Although the majority decided under the Fourth Amendment, the concurrence signals that future cases may develop an independent Michigan constitutional track.

Complex Concepts Simplified

  • Automobile exception: A rule allowing police to search a readily mobile vehicle without a warrant if they have probable cause that evidence/contraband connected to a crime is inside.
  • Probable cause: Not certainty—facts must create a fair probability that evidence of a crime (or criminal contraband) will be found in the place searched.
  • Civil infraction vs crime: Michigan law treats civil infractions as violations “which is not a crime” (see MCL 257.6a), typically punishable by noncustodial sanctions (fines/civil penalties), not incarceration. The Court used that distinction to calibrate Fourth Amendment “reasonableness.”
  • “Contraband” in this decision: The majority effectively uses “contraband” as a Fourth Amendment concept tied to criminal enforcement—rejecting the idea that anything unlawful under civil law automatically counts as contraband for warrantless automobile-search purposes.
  • “Smell of marijuana” evidence: Odor can still be a factor in probable cause after People v Armstrong, but it cannot do the work alone, and in Wilkins it also could not reliably establish the key element separating civil from criminal: quantity.

Conclusion

People v Wilkins establishes a significant Michigan precedent: the automobile exception cannot be used to conduct a warrantless vehicle search based only on probable cause of a civil infraction. In MRTMA cases, that means an officer must have probable cause to believe the vehicle contains evidence of criminal marijuana possession (by quantity) or evidence of some other crime; marijuana odor is not a per se shortcut to that conclusion. The decision both operationalizes voters’ decriminalization choice and narrows the risk that routine traffic stops—often involving civil violations—become de facto general searches.