States went too far in imposing criminal sanctions on anyone refusing to submit to a blood draw when accused of driving under the influence of alcohol (DUI). The US Supreme Court reached this verdict Thursday.

In delivering the opinion of the court, Justice Samuel Alito pointed out that one out of every five DUI suspects today refuses to submit to a breath test when arrested. This is largely a result of the escalating penalties that are imposed for DUI convictions. Because the suspect's cooperation is required to blow strongly enough for the breathalyzer machine to produce a reliable result, states like North Dakota have upped the stakes by making it a crime for a motorist to refuse to take "any" type of test -- blood, alcohol or urine -- when accused of DUI. The criminal penalty for refusal, a driver's license revocation for up to three years, is worse than the 90-day suspension and $500 fine imposed for a first DUI offense.

The court's analysis combined three similar cases. North Dakota motorist Steve Michael Beylund agreed to take a blood test after being threatened with criminal penalties if he refused, while North Dakota motorist Danny Birchfield refused to take a breath test. Minnesota motorist William Robert Bernard Jr refused a breath test after being told he was "required" to take it.

The justices found that there is nothing particularly onerous about providing breath evidence, since all humans must exhale air anyway. Blowing into a tube is neither difficult nor embarrassing, and it creates fewer privacy concerns.

"Blood tests are a different matter," Justice Alito wrote. "It is significantly more intrusive than blowing into a tube... In addition, a blood test, unlike a breath test, places in the hands of law enforcement authorities a sample that can be preserved and from which it is possible to extract information beyond a simple BAC reading."

The justices concluded that because of these differences, a breath test could be considered a "search incident to arrest" and be conducted without a warrant, while the more intrusive blood test would need a warrant. Imposing a criminal penalty for refusing to submit to a warrantless blood draw, the court reasoned, was going too far.

"There must be a limit to the consequences to which motorists may be deemed to have consented by virtue of a decision to drive on public roads," Justice Alito wrote. "And applying this standard, we conclude that motorists cannot be deemed to have consented to submit to a blood test on pain of committing a criminal offense."

The criminal penalty for refusing a breath test, on the other hand, was found acceptable. Thus, the court overturned the convictions of Birchfield and Beylund, but the justices upheld Bernard's. A copy of the decision is available in a 300k PDF file at the source link below.