The Minnesota Court of Appeals, raising constitutional concerns, overturned the conviction Tuesday of a man sentenced to five years in prison for refusing to submit to a blood test after he was arrested in Ramsey County for drunken driving in 2012.

Legal profession representatives said the 2-1 decision will have widespread implications for law enforcement.

The Ramsey County attorney's office issued a statement saying it "respectfully disagrees" with the appellate decision and will file a petition with the Minnesota Supreme Court asking it to reverse.

Incarcerated since 2012, Todd Eugene Trahan, 55, formerly of White Bear Lake, was informed Tuesday of the Appeals Court decision by the Star Tribune. "God bless the Court of Appeals," he said in a telephone interview from the Minnesota Correctional Facility at Faribault.

The Appeals Court said that Ramsey County authorities should have gotten a search warrant from a judge to conduct a blood test in the case it examined because of the "invasive" nature of using a needle to draw blood, compared with taking a breath.

It said there was no "compelling" reason to sidestep such a warrant in Trahan's case and thus the conviction "violates a driver's right to due process under the United States and Minnesota constitutions."

Joseph Daly, professor emeritus at Hamline University Law School, said that in the ruling's wake he would recommend that law enforcement officers in Minnesota not conduct blood tests of suspected drunken drivers without their permission or a warrant.

"I think Joe's analysis is a good one," said Bob Small, executive director of the Minnesota County Attorneys Association. He called the appellate ruling "a huge decision."

Trahan was stopped by a Ramsey County deputy just after midnight on Oct. 24, 2012, because of his erratic driving and speed, according to the appellate court memorandum.

When the deputy approached the car, "Trahan was screaming that he would be 'looking at doing 67 months,' " according to the court document.

The deputy observed that Trahan was agitated, smelled strongly of alcohol, had red and watery eyes and had difficulty standing up.

A check of his driving record disclosed that his license had been canceled "as inimical to public safety based on multiple previous … DWI convictions," the court said.

Because Trahan was "so agitated and unpredictable," the deputy did not administer field sobriety tests," the document said. At the jail, the deputy offered Trahan a blood test or a urine test. Trahan chose the urine test.

The parties' accounts differ on Trahan's compliance with providing a urine sample, according to the court record. Trahan contended that he provided a valid urine sample, while the deputy deemed his conduct refusal because he said Trahan put water from the sink into the sample bottle.

The deputy then asked Trahan to take a blood test, which he refused.

Trahan said in the interview with the Star Tribune that he had been at the hospital, had electrolytes pumped into him, had only "a couple of drinks," and had vomited.

"I wasn't saying I wasn't drinking, but I wasn't drinking to the point where I should have a DWI," he said.

Trahan was charged with first-degree refusal to submit to a chemical test in violation of statute and admitted in court to refusing the test. His sentence: five years in prison.

In its ruling, the Appeals Court said that had police offered Trahan a breath test and he refused, the state could have legally charged him for refusing that test, but requiring a blood test was different.

"Because a warrantless search of Trahan's blood would have been unconstitutional under these circumstances, Trahan's right to be free from unreasonable searches is implicated," wrote Appeals Court Judge Jill Flaskamp Halbrooks, who presided in the case. She was joined in her decision by Judge Margaret Chutich.

Judge Kevin Ross dissented.

Small said that the appellate ruling will have major implications for the arrest of people driving under the influence of controlled substances, rather than alcohol. Because a breath test cannot measure drugs in the body, blood tests are needed, and now officers will be unable to conduct those tests without permission or a warrant.

"That's a real significant thing," he said.

In his dissent, Ross said that the law was constitutional. But he said he believes the majority decision will ironically make things worse for impaired drivers.

Previously, he said, they could refuse a request to have their blood drawn without a warrant and face the consequences of being charged.

Now, as a result of the decision, Ross wrote, police will have no incentive to make a request, but instead will seek a warrant every time, and drivers will be force to have their blood drawn whether they like it or not.

Trahan said that had the deputy administered a breath test, it would have saved taxpayers a lot of money in fighting him in court, because refusing to take a breath test is proper grounds for conviction.

"I feel the court did right," Trahan said. "I feel that I was not treated fairly, they didn't go by the rules that were set out for them when I got pulled over. I wasn't even offered a breath test."