Marijuana and DWI Law in Minnesota: Navigating the Haze

In recent years, the State of Minnesota has taken a significant step toward marijuana decriminalization. In 2022, the State of Minnesota legalized the sale and consumption of edibles having lesser amounts of hemp-derived THC. In 2023, the State of Minnesota passed legislation allowing the recreational use of cannabis for ages 21 and older. This went into effect on August 1, 2023. The land of 10,000 lakes has joined the ranks of the growing number of states that have embraced the changing attitudes toward marijuana. While this marked a significant shift in the State’s approach to marijuana, it also presented many questions about its impact on driving safety and DWI laws.


Marijuana use can profoundly impair an individual’s ability to operate a vehicle safely. The extent of impairment varies from person to person and depends on factors such as strain, THC (tetrahydrocannabinol, the psychoactive compound in marijuana) potency, and an individual’s tolerance. However, some common impairments associated with marijuana use include slower reaction times, impaired coordination and motor skills, altered judgment and decision-making, and reduced attention and focus.


Minnesota has a strict DWI law that not only applies to alcohol but also to controlled substances, including marijuana. Under Minnesota law, it is illegal to operate a motor vehicle while impaired by any substance, whether that be alcohol, prescription medication, controlled substances, or cannabis. Despite the recent change in legislation legalizing marijuana use, the DWI law remains the same.

Many states have set a legal limit for THC in a driver’s system, such as 5 nanograms per milliliter of blood. Minnesota has not set a standard or identified an amount of TCH that defines what it means to be under the influence, meaning any amount in your systems is enough to prosecute.

Minnesota also tests for and can prosecute a person that has inactive marijuana in their system. Laboratory testing can detect inactive metabolites from the chemical breakdown of cannabis in your system. As a result, if you have used marijuana in the days before you were tested, it may still show up on the test in the form of inactive metabolites.

For instance, if law enforcement has reason to pull you over, and suspects that you may be under the influence, they can obtain a urine or blood sample from you, either with your consent or through a warrant. If that sample reveals inactive metabolites, the State could charge you with DWI.


Driving under the influence of marijuana in Minnesota can result in serious consequences. Penalties can include:

  1. Criminal charges: Depending on the circumstances, prior convictions, and the level of impairment, you may be charged with a misdemeanor, gross misdemeanor, or a felony level charge.
  2. License suspension: If you are arrested for a marijuana-related DWI and enter a guilty plea, your driver’s license may be suspended for a while.
  3. Fines and fees: You may have to pay fines, court costs, and legal fees. Fees range from a couple hundred dollars to thousands of dollars depending upon the level of the charge.
  4. Ignition interlock device: In some cases, you could be mandated to install an ignition interlock device in your vehicle at your own expense.
  5. Probation: You may be placed on probation, which can involve mandatory drug testing and other conditions.

It is crucial to understand that the penalties for marijuana-related DWI in Minnesota can be severe, and potentially lead to long-lasting consequences.


Defending against a marijuana related DWI charge can be complex. There is a lack of clarity of the legal definitions of impairment. THC affects individuals in diverse ways, creating variables that are difficult to measure. Potential defenses usually involve challenging some aspect of the case, such as reasons for the traffic stop, the results of the field sobriety test, or the accuracy of the testing. These cases involve blood or urine testing. If consent is not given, law enforcement needs to draft a warrant and get approval. One common defense is challenging the validity of the warrant. If a warrant is not valid, the blood and urine testing for THC is suppressed, meaning the test is not allowed to be used against you in legal proceedings.

Marijuana cases go to trial at a higher rate than alcohol related DWIs. The reason being is that Minnesota does not have a set legal amount for marijuana to be considered impaired, like there is for alcohol. This means that Standardized Field Sobriety Testing and Drug Recognition Experts become extremely important in a marijuana related DWI. At trial, a skilled attorney needs to be able to cross examine and question these witnesses. Your attorney needs to fully understand these processes and the signs of impairment law enforcement looks for.


As marijuana use becomes more prevalent in Minnesota, it is essential for individuals to understand the implications, especially related to driving under the influence. Minnesota’s DWI laws unequivocally apply to marijuana impairment, and the consequences of a marijuana-related DWI should be taken seriously. If you plan to use marijuana, it’s important to be responsible and avoid driving under the influence. Additionally, if you find yourself facing a marijuana-related DWI charge, consult with a knowledgeable and experienced attorney who can help you navigate the legal process and explore defenses.

Tom Hagen has been named the National Attorney of the Year, Minnesota Attorneys of the Year and has won many other awards. He focuses his practice on criminal defense with offices in Mankato and Rochester Minnesota. He has authored a book on DWI defense titled “Arrested for DWI: in Minnesota.”

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