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Smell, saliva and sobriety tests: How Minnesota law enforcement agencies hope to prevent DWIs via marijuana use

The area where most Minnesotans might notice enforcement of still-illegal acts are on the highway. State troopers and police officers are still charged with preventing driving while impaired.

State Patrol Chief Col. Matt Langer and Public Safety Commissioner Bob Jacobson
State Patrol Chief Col. Matt Langer and Public Safety Commissioner Bob Jacobson speaking at a recent public safety press conference on driving while high.
MinnPost photo by Peter Callaghan

Tuesday is MJ Day for recreational cannabis in Minnesota, the day when perhaps the most significant sections of the law take effect. Use and simple possession of the drug is no longer a crime for people 21 and over.

Retail sales are still well over a year away, but as of Aug. 1, those over 21 can use cannabis and possess 2 ounces or less in public, 2 pounds or less at home and grow up to eight plants in their homes or yards. 

But that doesn’t mean that criminal sanctions have been removed from state law regarding marijuana. As with alcohol, restrictions and regulations and penalties will exist for cannabis use, mostly in the areas of possession of illegal amounts and illegal sales. (See pages 26-42 here.)

The area where most Minnesotans might notice enforcement of still-illegal acts are on the highway. State troopers and police officers are still charged with preventing driving while impaired, something that has already included drivers impaired by alcohol, drugs or a combination of both.

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“We want to get word out to Minnesotans not to get behind the wheel if they choose to use cannabis or any other impairing substance,” said Col. Matt Langer, the chief of the Minnesota State Patrol. The state has launched a public awareness campaign with slogans such as “Driving high is a DWI,” “Driving high leads to serious lows,” and “Drive the highway, not the high way.”

“If you feel different, you will drive different,” said state Office of Traffic Safety director Mike Hanson.

Even before the Legislature signaled during the 2023 session that it would legalize use and possession of marijuana, there has been a steady increase in drugged driving cases including impairment from multiple substances, including alcohol, Langer said. Between 2012 and 2016, the state had more than 7,000 drugged driving incidents. Between 2017 and 2021, there were nearly 16,000 incidents.

And of the 197 highway deaths this year, 29 were alcohol impaired, 21 were drug impaired and 13 were impaired by a combination of both.

Here are some of the ways traffic enforcement will change when marijuana use and possession by adults becomes legal.

It’s still illegal to drive impaired by cannabis

“If you do choose to partake in cannabis consumption … our message is the same one we provide for alcohol for many, many years,” Langer said. “Plan ahead and never drive when impaired by any substance at all.”

A typical first-time offender found to be impaired faces license suspension, from 30 days and up to a year, possible jail time, fines and court costs. While alcohol-impaired drivers are presumed to be in violation with a blood-alcohol level of 0.08%, they can be found guilty at lower levels based on field sobriety tests by police.

When retail stores open, perhaps in the spring of 2025, they are required to post warnings about impaired driving. The law also makes it illegal to use cannabis in a motor vehicle and to possess cannabis in an open container in a motor vehicle.

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Absent roadside testing like they have for alcohol, police will rely on field testing and experts trained to detect impairment from drugs.

It is still illegal to pilot a boat or operate an ATV or snowmobile impaired

Col. Rodmen Smith, director of the enforcement division of the state Department of Natural Resources, said all the same rules apply to motorized recreational vehicles and watercraft as apply to cars and trucks.

“It’s all the same. All the rules apply, whether it’s a motor vehicle or an ATV or a snowmobile or a watercraft,” Smith said. That dates back to 2018 when an 8-year-old boy was killed by an impaired snowmobiler. A conviction for a DWI in a car affects the ability to legally operate a snowmobile or boat and a conviction of operating those vehicles while impaired affects the legal privilege to drive a car.

“The important message here is impaired driving is impaired driving,” he said. 

What might happen if you are stopped?

Langer said troopers will rely on training and observation to decide whether to stop and whether to cite drivers. Troopers and police officers will look for similar evidence of impairment as they do now — weaving between and among traffic lanes, changing of speed, other forms of erratic driving. Once a driver is stopped, officers can be tipped off by odors and by behaviors of a driver.

“They look for things such as body tremors, failure to control speech, manner of speech, change of pupil size, bloodshot or watery eyes, and a host of other effects,” Langer said.

A driver can be taken into custody and a blood test can be taken to determine whether THC or other drugs are present. But there is no agreed-upon concentration level to prove impairment as there is with blood-alcohol levels. And because THC can remain present in a test long after it would have caused impairment, a positive test alone isn’t adequate in most prosecutions.

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Troopers and police officers are also able to call in a specially trained officer known as a drug recognition expert who is trained in detecting physical evidence of impairment.

The new law also sets aside money for the “training of peace officers and law enforcement agencies on changes to laws involving cannabis flower, cannabis products, lower-potency hemp edibles, and hemp-derived consumer products and the law’s impact on searches and seizures.”

James Gempeler is a St. Paul criminal defense attorney who includes DWI defense in his practice. He said procedures for a marijuana impairment violation are similar to alcohol, absent of course, the breathalyzer test. There is also a requirement in state law for drivers to cooperate with testing or face automatic loss of driving privileges. There is no such requirement for drivers to cooperate in a field sobriety test or an inspection by a drug recognition expert.

“I don’t see any reason why you would have to,” he said. It would only make it easier for prosecutors to win a conviction and there is no legal consequence for refusing.

That said, Minnesotans tend to cooperate with evaluations, he said.

You have to remember, we are Minnesota nice,” he joked. “Literally, 90% of people pulled over will admit to drinking, not to the full extent of being intoxicated, but to having had a drink.”

Smell test

Back in the pot-is-illegal days, a police officer who smelled marijuana on a driver or in a car could use that alone as probable cause to conduct a search of a car without first obtaining a search warrant from a judge. Such warrantless searches have been upheld by both state and federal courts, though two current state court cases are raising the issue again. One, State v. Torgerson from Meeker County, was argued before the state Supreme Court in April with the justices exploring “whether law enforcement officers who smell the odor of burnt marijuana emanating from a lawfully stopped vehicle have sufficient probable cause to search the vehicle under the automobile exception to the warrant requirement.”

That decision is pending.

Another recent appeals court case in State v. Lindekugel found that odor remains enough probable cause for a search but that it is better for it to be part of the “totality of the circumstances.

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“As the state correctly asserts, we are bound by precedent,” the appeals court wrote in that decision. “Until that precedent is changed, the smell of marijuana emanating from a vehicle gives police probable cause to search that vehicle for contraband. Accordingly, the district court did not err by concluding that the officer had probable cause to search Lindekugel’s vehicle based on the smell of marijuana.”

Defense lawyers are anxious for the results of the cases.

“With the new law, we’re all gonna find a way to litigate this,” Gempeler said. “It’s gonna be muddy for a while unless we get more guidance from those who allegedly know more than us. I think there is some gray area, and there are going to fights. The aroma of marijuana isn’t illegal anymore.” 

That said, both cases arise from incidents prior to legalization. Smell alone could simply mean that a 21-or-older passenger had smoked before getting into the car, a completely legal act come Aug. 1. Other states that have legalized recreational marijuana specifically stated that odor of marijuana could no longer justify a warrantless search of a car. Minnesota lawmakers were aware of those provisions elsewhere but did not include a prohibition on relying on odor in House File 100. 

And odor? 

“A lot of the correlations are drawn between cannabis and alcohol,” Langer said. “If someone stops a vehicle and they either smell alcohol — which can happen if there’s an open bottle and its spilling in the center console or the floor — or someone smells of alcohol because they’ve been drinking, it piques the trooper’s interest to look further into that situation to see if there is a violation of the open container law or an impairment problem with the driver — or both.

“Cannabis is different in some ways. The smell can change whether it is fresh or it is burnt and we also have edibles. So you can’t draw a direct correlation between alcohol and cannabis as one-to-one or apples-to-apples,” Langer said. “But if troopers encounter a vehicle and it smells like the occupants have been smoking marijuana, you can bet the trooper will be looking further into that situation to see if there is a violation.”

Gempeler said the easiest way to get around the issue is to get a search warrant after someone has been arrested and their car impounded. But that does not help if an officer is trying to determine at roadside if a driver is impaired enough to arrest.

Open containers

Similar to alcohol, cannabis products cannot be possessed in a car in open containers. It can be transported as long as it is in a trunk or in a part of a vehicle not reachable by the driver or passengers, say in the back of an SUV. But there are a few specific provisions in the new law that apply to cannabis specifically. It must be in its original packaging, unopened and with the package seal intact.

So a zip-lock baggie with two ounces or less (the legal public possession limit) in the front seat of a car is not legal. An officer who sees it can cite a driver, but the penalty would likely only be for a petty misdemeanor —no jail time and a fine of $300 or less.

“If you are going to be transporting cannabis in your vehicle, it can only be in the original packaging that is sealed or, if it is open, it has to be in the truck or some place that’s well outside the reach of the driver and the passengers,” Langer said.

What is a DRE?

Drug recognition experts are specially trained and certified police officers can conduct more-extensive evaluations of drivers suspected of being impaired by something other than alcohol. They already exist in Minnesota, with about half of the 300 working for the State Patrol. They can consult with an officer on the roadside by phone or radio, travel to the scene or, most likely, meet an officer and a suspect at a police office or precinct.

The evaluation takes 30-to-50 minutes, Hanson said.

“They are looking at the physiology of the person placed under arrest, some of the physical indicators of the different drug categories — some of them speed us up, some of them slow us down,” he said. “Oftentimes the conviction is keyed upon evidence the DRE can bring in based on their experience and their training and their observations of that individual.”

Gempeler agreed.

“If they don’t do the drug recognition analysis, they are giving a large opportunity for us defense attorneys to fight back,” he said. Gempeler said he recently won a case when there was no DRE involved.

The new law sets aside $10 million in the first year and $5 million each year after that to train and employ additional DREs, to hire additional phlebotomists (blood takers and testers) and to train other officers in drug recognition. At the same time, however, dogs trained to sniff out marijuana will be retired. 

Oral fluid pilot program

There is no accepted roadside test of oral fluids — saliva — and no accepted concentration reading to be a presumption of impairment. There are impairment tests for oral fluids in the testing phase, and Minnesota will conduct pilot testing starting Sept. 1. 

Drivers who are stopped for suspicion of driving under the influence of marijuana will be asked if they would be willing to help out with the pilot project. The oral fluid test must be conducted by a drug recognition expert and the results would be compared to blood testing. The results of the test can not be used as reason for making an arrest or in any legal proceeding.

The commissioner of public safety must prepare a report to the Legislature by February 2025 on the accuracy and practicality of the oral testing pilot.

“We want to use it as a screening test the same way we do with the PBT (preliminary breath test),” Hanson said.

Why would a driver cooperate? Again, Gempeler cited Minnesota Nice. “I can see people saying ‘sure.’”

Editor’s note: An earlier version of this story inadvertently listed “drug impaired” traffic deaths twice. The story has been updated to reflect that one of those numbers was for alcohol impairment.