When it comes to arresting you for a Minnesota DWI, the police officer must first have probable cause to believe that you are indeed under the influence.
Local law enforcement officials are trained to observe a driver’s actions and take note of any signs that may support the suspicion of impairment. After stopping your vehicle, the officer may be on the lookout for indications such as slurred speech, fumbling or not being able to locate your driver’s license, or the odor of an alcoholic beverage on your breath.
Once you are pulled over, the officer may attempt to make small talk and ask you questions such as where you came from and where you are headed. The law does not require you to answer these queries. It is possible that the officer may simply be asking these questions to help him determine whether or not there is an alcoholic odor present that might justify his arresting you for driving under the influence. Do not admit to drinking even if you were, because that admission is all the officer needs to make you perform field sobriety tests.
In many instances, a police officer will instantly assume that the slightest odor of an alcoholic beverage will mean that you are intoxicated. Later on, officers may even describe this odor further by categorizing it as slight, moderate or strong in order to support their case.
In most situations, however, alcohol consumption does not immediately relate to intoxication. Remember, it is not illegal for most drivers aged 21 and above to drink and drive if they do not have alcohol restrictions on their licenses. It is only considered illegal to be intoxicated or impaired while operating a motor vehicle.
The estimated strength of alcoholic odor is typically unrelated to the driver’s actual BAC levels. The detection of an individual’s BAC by basis of odor is far from accurate. It is very possible for motorists to be impaired or intoxicated without producing sufficient odor to alert an officer. Ethanol, after all, has no scent.
All that can be gathered from the odor of alcohol on the driver’s breath is that he or she likely consumed an alcoholic beverage recently. It does not provide enough evidence that he or she had enough to be under the influence or have a BAC of .08 or higher.
The Insurance Institute for Highway Safety supported a scientific study that determined that the odor of alcohol is not a reliable and sufficient probable cause to request a chemical test or arrest a driver for DWI.
Given the sheer difficulty of estimating an individual’s BAC from the strength of his or her alcohol odor, using odor as a form of evidence should definitely not be relayed to a jury in a DWI case, and should not even be used to back probable cause for an arrest.