The Wisconsin Supreme Court ruled that the standard of probable cause to apply a breath test to a driver is lessened when an officer has knowledge that the driver has had three or more OWI convictions. With three or more convictions, a driver is subject to a stricter alcohol concentration level (PAC) of .02 when operating a vehicle.

The ruling stems from a case involving Steve Goss who had four OWI convictions when he was pulled over for an obstructed license plate. Knowing he had these convictions, police administered a breath test because they smelled alcohol coming from him. He was measured with a blood alcohol level of .084, but Goss challenged the breath test, protesting that the officers did not have probable cause to give the test.

The odor itself was enough probable cause, the court ruled. "In this case, both the smell of alcohol and the officer's knowledge that Goss could drink only a very small amount before exceeding the legal limit that applied to him make the conclusion that Goss was likely in violation of the statute highly plausible," the court stated.

Furthering their explanation, the court said the reduced standard for probable cause for drivers who must abide by the .02 PAC law is necessary "because the ordinary physical indications of intoxication are not typically present in a person with that level of blood alcohol content."

Given normal circumstances, if a police officer requests a breath sample, it can only be administered if the officer has "probable cause to believe" a non-commercial driver is in violation of the state's OWI law. Odor alone may not be enough of a probable cause for officers to breath test drivers with two or fewer OWI convictions because these drivers can still operate vehicles with a blood alcohol concentration level of .08 or less.

Source: State bar of Wisconsin, "Probable cause standard different for .02 PAC cases, supreme court clarifies," Joe Forward, Dec. 27, 2011