Legal Question in DUI Law in Wisconsin

OWI, Drunk Driving, DUI, Police Running License Plates in Tavern Parking Lot

Car license plate numbers are public information in which there is no reasonable expectation of privacy if a vehicle travels on a public roadway. Law enforcement officers investigating crimes often perform record checks based upon plate numbers, and are not required to have probable cause to arrest beforehand. Likewise, parking lots of public establishments have no expectation of privacy, so anyone, including a law enforcement officer, is lawfully able to observe its vehicles including their plate numbers. Drivers with prior drunken driving convictions would therefore be wise to leave their vehicles at home if they are going to a bar, for several good reasons including their own safety and that of others. Such drivers are apt to get "special" attention" from authorities when their vehicles are spotted at a drinking establishment. All this being said, however, prior to stopping a vehicle, even for a repeat drunk driver, the officer must observe suspicious conduct such as violation of a rule of the road. In WI, case law clearly defines probable cause to stop a vehicle as illegal driving of some sort. Hence, even a person with prior convictions cannot be legally stopped for that reason alone (unless their license is still revoked for the prior conviction). Officers are therefore apt to follow them for long distances looking for clues of intoxication and pull them over more quickly than other similarly situated drivers. Probable cause to stop a vehicle is also easier to establish for drivers with clean records if they are seen leaving drinking establishments. Observable signs of intoxication (i.e., staggaring before stepping into the vehicle) could substitute for bad driving in this regard. Ethically speaking, it is an officer's job to apprehend drunken drivers by all lawful means for protection of the public as well as for the protection of the drivers themselves. I therefore do not see how checking the license plates of vehicles at a tavern is unethical, so long as the officer observes the presumption of innocence for all drivers, regardless of their records, and does not detain them without observing a fresh traffic law violation.