The Minnesota Court of Appeals on Monday held that the state cannot prosecute drivers for refusing to submit to warrantless urine tests.

Reversing the Steele County conviction of Ryan Thompson, the court said the case affects “his fundamental right to be free from unconstitutional searches.”

Thompson was stopped outside an Owatonna bar at closing time April 13, 2012, after his car jumped a curb, “cut the corner short” and went over the center line as he left the parking lot, according to a police officer.

The officer “detected an overwhelming odor” of an alcoholic beverage coming from the vehicle and noticed Thompson had glassy eyes, according to court records. Thompson, who said he had one beer, failed a field sobriety test, refused to take a blood or urine test and was charged with second-degree test refusal.

The U.S. Supreme Court ruled in 2013 that police usually must try to obtain a search warrant before ordering blood tests for drunken-driving suspects.

The midlevel state appeals court issued a similar ruling in October. On Monday, it extended that ruling to urine tests.

Meanwhile, the U.S. Supreme Court will decide whether states, including Minnesota, can criminalize a driver’s refusal to take an alcohol test if police have not obtained a search warrant.

In the case from Minnesota, police arrested William Bernard after his truck became stuck as he was trying to pull a boat out of a river in South St. Paul. Officers smelled alcohol on his breath and said his eyes were bloodshot, according to records. After Bernard refused to take a breath test, police took him into custody.

Bernard was charged with a first-degree count of refusal to take a breath test, which carries a mandatory minimum sentence of three years in prison.

He argued that the refusal law violated his Fourth Amendment rights by criminalizing his refusal to submit to a search. A divided Minnesota Supreme Court upheld the law, finding that officers could order a breath test without a warrant as a “search incident to a valid arrest.”

In the Owatonna case, the Court of Appeals said, “We conclude that, as with a warrantless blood test, a warrantless urine test cannot be justifield under the “search incident-to-arrest exception.”

“Because a driver must produce a urine sample in front of an officer, a urine test is unquestionably more intrusive than a breath test,” Judge John Smith wrote for the three-judge panel.

Thompson’s attorney, Charles Ramsay of Roseville, said, “I think the decision will help Minnesota fall in line with the federal Constitution, and I’m happy with the direction Minnesota is taking.”

He said, “This is the last link in the chain for the three drunk-driving tests: breath, blood and urine.”

Steele County Attorney Daniel McIntosh could not immediately be reached for comment.

Hal Davis can be reached at 651-228-5302. Follow him on Twitter @haldavis3.