Does Marijuana Smell Alone Give Police the Right to Search? What You Need to Know

The legal status of marijuana in the United States has evolved since California became the first state to legalize marijuana for medicinal use in 1996. According to the National Conference of State Legislatures (NCSL), 24 states have legalized marijuana for recreational use as of March 2025. Many more states have legalized marijuana for medicinal use only or decriminalized the possession of small amounts, while marijuana remains fully illegal in a few states and under federal law.

As the legal consequences for marijuana possession change across the country, so have procedures for how police enforce marijuana laws. Here's an overview of how states have split on whether the smell of marijuana alone justifies a police search.

What Is the Plain Smell Doctrine?

Before the marijuana legalization movement, police in all states relied on a rule called the "plain smell doctrine" to justify warrantless searches for marijuana. Under this rule, an extension of the plain view doctrine, a police officer who smelled marijuana during a lawful encounter could typically search for it without having to get a search warrant.

The plain smell doctrine was often used to justify warrantless car searches during traffic stops. A common scenario went like this:

• Lawful encounter. An officer pulled a driver over for speeding or some other traffic violation.
• The odor of marijuana. The officer reported smelling an odor of burnt or raw marijuana coming from the car while writing a traffic ticket.
• Warrantless search. The officer used the smell of marijuana as probable cause to conduct a warrantless search of the vehicle because the odor alone gave the officer reason to believe that the driver was committing or had committed the crime of possessing or transporting marijuana.

On federal property and in states, such as Idaho, where all marijuana remains illegal, the smell of marijuana still implies criminal activity and is enough to justify a warrantless search of someone's person or vehicle without a warrant. Applying the rule is more complicated in states that have legalized marijuana.

How Marijuana Legalization Has Changed the Plain Smell Doctrine

There is no uniform approach to how the plain smell doctrine applies in states where marijuana use is now allowed for medical or recreational purposes. Here's an overview of how some state lawmakers and courts have come down on the issue. Keep in mind that marijuana laws are changing rapidly across the country. If you have questions about the laws in your state, talk to a criminal defense lawyer.

State Laws

Lawmakers in a few states that have legalized marijuana have also passed laws specifically banning officers from using the plain smell doctrine to justify warrantless searches for marijuana. For example, Virginia law clearly states that no law enforcement officer may "lawfully stop, search, or seize any person, place, or thing" solely based on the odor of marijuana. (Va. Code § 4.1-1302 (2025).)

Similarly, Maryland law prohibits law enforcement officers from stopping or searching a person or vehicle based on the odor of "burnt or unburnt cannabis." (Md. Crim. Proc. Code Ann. § 1-211 (2025).)

After the Minnesota Supreme Court ruled that officers can't use the smell of marijuana as the only reason for a vehicle search, lawmakers passed a statute that supported the decision in 2024. (Minn. Stat. § 626.223 (2025).)

State Court Decisions

In the absence of a state law on the issue, courts across the country have had to decide how the plain smell doctrine applies in the era of marijuana legalization.

States Where Recreational Marijuana Is Legal

In many states where adult recreational use of marijuana is legal, courts have ruled that the smell of marijuana alone isn't enough to justify a warrantless search because state law allows its possession and use under some circumstances. Instead, in these states, the smell of marijuana is one factor that may play a role in the probable-cause determination. Officers must be able to point to additional evidence, such as driver impairment or visible contraband, to justify a search for evidence related to a crime like driving under the influence of marijuana, driving with an open container of marijuana, or possessing marijuana for sale. Examples of states that take this "totality of the circumstances" approach include Michigan, Massachusetts, and Vermont.

States Where Medical Marijuana Is Legal

In states that have legalized medical but not recreational marijuana, courts are more likely to allow searches based on the odor of marijuana. For example, in Wisconsin, where some cannabidiol (CBD) is legal with a prescription, the Supreme Court has ruled that officers aren't required to make a reasonable inference in favor of innocence and instead can search a car without a warrant based on the smell of marijuana alone. Similarly, while the Supreme Court in Florida has yet to weigh in on the issue, many appellate courts have ruled that the odor of marijuana is enough to justify a vehicle search even though medical marijuana and hemp are now legal in the state. (Hoehaver v. State, 389 So.3d 766 (Fla. 5th DCA 2024).)

In contrast, in Pennsylvania, the Supreme Court has ruled that the odor of marijuana alone isn't enough to justify a warrantless search, even though only medical marijuana cardholders can legally possess it in the state.

Circumstances That Might Justify a Search Even In States Where Marijuana Is Legal

Even in states where medical and recreational marijuana use is legal, there are limitations and restrictions on its use. If the police have reason to believe that you have violated these limits and your car contains evidence of the violation, they'll likely be able to search it without a warrant. Common scenarios include:

• you look underage (the legal age for marijuana use is 21 in most states)
• you show signs of driving under the influence of marijuana
• you have more than the legally allowed amount of marijuana, or it's in an open container
• you are in a place where marijuana is prohibited (such as federal property or a school zone), or
• there is reason to believe you are selling marijuana.

What If a Police Officer Asks to Search My Vehicle?

Officers sometimes ask for permission to search a vehicle during a traffic stop. They often ask for consent when they don't have legal justification for a warrantless search. You are not required to consent to a search. If you do, the government can use whatever they find against you in court. Instead, you can politely decline by telling the officer that you don't consent to a search. By refusing to consent, you might prevent the search from happening at all or prevent the government from being able to use whatever contraband they may find against you down the road.

Will I Have to Perform Field Sobriety Tests If an Officer Smells Weed?

An officer who smells marijuana during a traffic stop is going to look for signs that you might be driving under the influence of marijuana, such as red eyes or delayed reaction time. The officer might ask you to perform several "field sobriety tests" (FSTs). These tests were designed to detect alcohol impairment, but law enforcement agencies across the country also use them to assess marijuana impairment.

FSTs are voluntary, and you can refuse to perform the tests. However, refusing doesn't necessarily mean you're in the clear—you'll still be arrested if there's probable cause to believe you're impaired, and if you are arrested and charged with a DUI, the prosecution might be able to use the fact that you refused to participate in FSTs as evidence against you at trial.

And while you can refuse field sobriety tests, each state has some form of "implied consent" law that requires drivers who are arrested for DUI to take a blood, breath, or urine test to check for the presence of alcohol or drugs in a driver's system. Drivers who refuse post-arrest chemical tests face consequences, including lengthy driver's license suspensions.

Talk to a Lawyer

Search and seizure laws continue to evolve as more states legalize and decriminalize marijuana. It's important to understand the specific laws and court decisions in your state. If you've been arrested or charged with a marijuana-related offense, talk to a criminal defense lawyer. A lawyer can review your case and file a motion to suppress if the police searched you unlawfully.

Keep in mind that driving under the influence of marijuana remains illegal everywhere, and even states that allow adults to use marijuana have rules about how much you can possess and where you can use it.