St. Paul, MN (Learfield Wire Services) - The Minnesota Court of Appeals says warrantless blood and urine tests are unconstitutional.

In an opinion published Monday, the court reversed the conviction of an Owatonna driver who refused to take a blood or urine test after he was arrested on suspicion of driving under the influence in 2012. Ryan Thompson was charged with second-degree test-refusal, third-degree driving while under the influence, obstructing legal process, and driving over the centerline after an officer stopped him outside a bar. Thompson was eventually convicted of second-degree test refusal. The other charges were dropped.

Thompson argued the state's test-refusal law violated his Fourth Amendment rights, which protects against unreasonable searches and seizures.The statute makes it a crime to refuse to submit to a chemical test of blood, breath or urine under certain circumstances, such as when an officer has probable cause to believe a person was driving or operating a motor vehicle under the influence of alcohol.