Missouri Vehicle Search Consent and the Amendment 3 Odor Rule

The operative language is Article XIV, Section 2, subsection 10, subdivision (10) of the Missouri Constitution. Voters approved it as Amendment 3 on November 8, 2022, and it took effect thirty days later on December 8, 2022. Because it is constitutional text, the General Assembly cannot narrow it by ordinary statute, and no Missouri city or county may adopt a conflicting rule: subsection 10(1) states that the listed adult conduct is not an offense "under state law or the laws of any local government within the state" and shall not "be a basis to detain, search, or arrest."

The conduct protected is defined by quantity. Subsection 10(1)(a) covers purchasing, possessing, consuming, transporting or giving away three ounces or less of dried, unprocessed marijuana or its equivalent by a person at least twenty-one years old. Subsection 10(1)(b) covers up to six flowering plants, six nonflowering plants over fourteen inches, and six clones under fourteen inches, provided the grower is registered with the Department of Health and Senior Services and the plants sit in a locked space at one private residence out of unaided view from a public place. Stay inside those numbers and the constitution says the marijuana is "not contraband nor subject to seizure."

Read the exception carefully, because it is the whole of it. Subdivision (10) suspends the odor protection only "when law enforcement is investigating whether a person is operating a motor vehicle, train, aircraft, motorboat, or other motorized form of transport while under the influence of marijuana." That is a driving-impairment inquiry, not a general search licence. Alongside it, subsection 3 of the same section preserves three vehicle-related prohibitions and no others: paragraph (d) operating or being in physical control while under the influence, paragraph (e) consuming while the vehicle is being operated, and paragraph (f) smoking inside a motor vehicle, train, aircraft or motorboat while it is being operated. Missouri drivers should note what is absent from that list. Unlike Illinois and Ohio, Missouri never enacted a sealed-container, odor-proof-packaging or trunk-storage requirement for adult-use cannabis in a car.

A second, older clause reaches medical patients and everyone else. Article XIV, Section 2, subsection 7(6) provides that "Evidence of marijuana alone, without specific evidence indicating that the marijuana is outside of what is lawful for medical or adult use, cannot be the basis for a search of a patient or non-patient, including their home, vehicle or other property." The same subdivision requires an officer to knock or announce before entering premises on a marijuana search warrant, and requires the officer to check the Department's registry for a cultivation card before applying for a cultivation warrant.

Missouri also builds a paper trail around both marijuana searches and ordinary traffic stops. Under subsection 7(7)(a), an officer who executes a marijuana search warrant or conducts a warrantless marijuana search must report the probable cause or exigent circumstances relied on, whether marijuana or other contraband was found and seized, a description of the tactics used to enter the property, and whether an arrest followed. Agencies compile that annually and file it with the Attorney General by March 1, who summarises it for the Governor and General Assembly by June 1. Separately, Mo. Rev. Stat. § 590.650.2(4) requires an officer at every vehicle stop to record whether a search was conducted, whether the individual consented to it, the probable cause for it, whether the person or the property or both were searched, and the duration of the search. Section 590.650.6 lets the Governor withhold state funds from an agency that fails to comply, and § 590.650.8 exempts stops made at a lawfully conducted sobriety checkpoint from the reporting duty.

One further Missouri distinction matters for phone searches. Missouri voters amended Mo. Const. art. I, § 15 on August 5, 2014 to add "electronic communications and data" to the list of things secure from unreasonable search, and to require a warrant to describe "the data or communication to be accessed." A consent request to look through your phone during a traffic stop is asking you to give up a right that Missouri wrote into its own constitution.

Refusing consent is not itself an offense in Missouri. The interference statute, Mo. Rev. B. 1(1) reaches resisting your own stop only by violence, physical force or flight. Saying you do not consent is none of those. The remedy for a search that goes ahead anyway is a written motion to suppress under Mo. Rev. 296, filed in the court where the criminal case is pending, normally before trial begins unless you were unaware of the grounds. 5 lists the available grounds, including that the search was made without a warrant and without lawful authority, and that it violated Section 15 of Article I of the Missouri Constitution or the Fourth and Fourteenth Amendments.

6 puts both the burden of going forward and the risk of nonpersuasion on the state, which must show by a preponderance of the evidence that the motion should be overruled. 301 or another law requires it to be held. 650 stop data but does not adjudicate individual stops.