Court ruling upholds DUI conviction based on warrantless BAC test

Court ruling upholds DUI conviction based on warrantless BAC test

We have previously written that police officers in Wisconsin have to follow specific rules and procedures before they can arrest someone for suspected drunk driving. Before a suspect can be given a breath, blood or urine test, the officer must perform a field sobriety test to determine if there is probable cause to make the arrest.

Furthermore, none of the three different tests to measure blood alcohol concentration (BAC) are foolproof. Mistakes are often made. Depending on how they are handled, tests become an opportunity for an appeal or a wrongful conviction.

Many other states also struggle with procedural issues related to DUI arrests. For instance, a recent ruling by the Minnesota Court of Appeals expanded police powers to administer urine tests without a warrant.

The court heard the appeal of a 2009 DUI conviction that was based on the results of a urine test. The defendant was originally pulled over for speeding but was later arrested for DUI.

There was no precedent that allowed police to collect a urine sample without a warrant. However, the officer demanded a sample under the state’s “implied consent” statute. That sample was later used to convict her.

On appeal, the woman argued that her Fourth Amendment rights were violated by the officer’s lack of a warrant. However, the court upheld her conviction, saying that exigent circumstances allowed the officer to bypass the need for a warrant.

An expert witness for the prosecution argued that waiting for a warrant could alter a defendant’s BAC just enough to bring it within legal limits. For instance, waiting 15 minutes could cause a BAC reading in the bladder to change from 0.081 percent to 0.079 percent.

Unfortunately for Minnesotans, this ruling expands police powers to compel defendants to submit to warrantless DUI testing by police. More alarmingly, it also provides the precedent for a systematic violation of everyone’s constitutional rights.

Source:, “Minnesota: Appeals Court Expands DUI Implied Consent Reach,” July 8, 2011