Evidence of Alcohol Impairment: Something Smells Funny

Posted On December 08, 2011 by Charles Ramsay

One common indicia of alcohol consumption is "odor of alcohol.| Nearly every DWI police report will start with a mention of this odor, usually as soon as the officer gets within five feet of an alleged drunk driver. And it won't just be an |odor.| It will be further defined by the officer, usually as a |moderate| odor, sometimes a |strong| odor, and on special occasions as an |overwhelming| odor. Sounds like damning evidence, right? It is, unless (like us) you know exactly how to fight in DUI cases.

Minnesota's appellate courts certainly believe so. One recent example comes from the case of State v. Koppi (Minn. 2011) where our own Supreme Court ruled in the driver's favor, but did so in an interesting way. In the Koppi case, the officer (no doubt honestly) described the odor of alcohol as |slight.| The Supreme Court emphasized this characterization, noting that 95% of all drunk drivers exhibit at least a |moderate| or |strong| odor of alcohol (at least, according to the officer - a point we'll revisit in a moment). The court ruled in Koppi's favor largely because he only had a |slight| odor of alcohol.

Compare Koppi with State v. Nur (Minn.App. 2011), which dealt with the exact same legal issues . . . but had a dramatically different result. Although both cases involved DWI arrests, the officer in Nur's case described his odor of alcohol as |strong.| When the court ruled against Nur, it emphasized the difference between a |slight| odor of alcohol and a |strong| odor, and adopted as fact the assertion that 95% of drunk drivers exhibit a |moderate| to |strong| odor of alcohol. In State v. Mahoney (Minn.App. 2011), another case with legal issues identical to those in the Koppi case, the court stated, |the deputy in this case testified that he smelled a |strong| odor of alcohol on Mahoney's breath. This evidence stands in contrast to evidence that Koppi had only a |slight odor of alcohol.| So, it's clear that the courts put great weight on how strong any alleged odor of alcohol really is.

This just begs the question, |when a police officer describes an odor of alcohol as |slight,| |moderate| or |strong| do they have a scientific basis for doing so?| Put another way, when a person's breath is described as having a |strong| odor of alcohol instead of |slight,| does that actually mean that the driver is more drunk? Does odor of alcohol provide any meaningful indication that someone is |intoxicated,| or does it just merely mean that they may have consumed alcohol?

A scientific study, supported by the Insurance Institute for Highway Safety and published in a peer-reviewed journal, quickly determined that odor of alcohol is a mostly useless indicator when deciding whether to arrest a driver for DWI. In fact, after conducting their study, the authors actually came up with this conclusion:

Odor strength estimates were unrelated to BAC levels. Estimates of BAC level failed to rise above random guesses.

This study confirmed - via the scientific method - what our attorneys have long suspected. An officer's description of the odor of alcohol as |strong| is just as useless a fact as if the officer had called it |slight| or |overwhelming.| Someone who really is drunk will be described as having a |slight| odor of alcohol, while someone who is perfectly capable of driving will, as often as not, be described as having a |strong| odor of alcohol.

This type of evidence, which doesn't even rise to the level of |random guesses,| should never be presented to a jury in a DWI case, and should not even be used to support probable cause to arrest. We continue to educate the courts about how useless this |evidence| really is, but until the day comes that we no longer read about the distinction between |slight| and |strong| when describing odor of alcohol, our only choice is to fight, and fight, and fight!