Blood-alcohol tests and the warrant requirement

The Fourth Amendment requirement that the police obtain a warrant prior to searching someone's home, for example, is well-known. This requirement also applies to physical intrusions into the body, such as the taking of blood to determine blood-alcohol content. However, this right is not absolute, and it is important to be aware of what is permissible and what is not. One of the exceptions to the Fourth Amendment's requirement of a warrant is emergencies, such as the need to provide emergency assistance to a home's occupant or continue the pursuit of a fleeing suspect. Another exception, and the one that applies most closely in DUI cases, is the need to prevent the destruction of evidence.

The United States Supreme Court has emphasized that this determination can only be made on a case-by-case basis looking at all the circumstances as whole. In a 1966 case, the Court held that a blood sample could be obtained by the police without a warrant because of the risk, based on the circumstances of that case, because of the risk that evidence would be "destroyed"; which is to say the alcohol in the suspect's blood would be filtered out by the liver and would no longer appear on the blood test. In 2008, the Minnesota Supreme Court cited this case (among others) in ruling that the risk of alcohol dissipating in the bloodstream created an automatic exception to the Fourth Amendment's requirement that police obtain a warrant.

Such was the law in Minnesota until earlier this year. This last term, the U.S. Supreme Court considered a case from Missouri where a man was pulled over because a police officer suspected him of driving under the influence. The man failed the field sobriety test, and then refused to take a Breathalyzer. Missouri, like Minnesota, has a law that makes it a crime to refuse to take a breath test. After his refusal, the police officer placed the driver under arrest and took him to a local hospital in order to draw blood to test his BAC. The Supreme Court reaffirmed the requirement that courts look at each case under its specific circumstances.

In the case of the Missouri driver, the Court noted the changes that have occurred since 1966 in terms of streamlining the warrant process: most states, including Minnesota, allow for search warrants to be obtained via teleconference and the like without the officer having to physically appear before a judge. In addition, the Court pointed out that some delay is inevitable anyway, because the arresting officer will need to take the suspect to a hospital or otherwise find medical assistance in drawing blood. The Supreme Court concluded, therefore, that a drunk-driving arrest does not automatically create an exception to the warrant requirement of the Fourth Amendment prior to a search by the police. In the case of the Missouri driver, the Court upheld the state courts, which had found that the search was improper and therefore inadmissible. Once again, this was based on the circumstances of that case, and there may very well be situations where a warrantless blood test could be acceptable.

The Supreme Court emphasized repeatedly that each case must be taken on its own facts. Thus, if you find yourself accused of any crime, DUI or otherwise, it is imperative that you find competent legal representation as soon as possible.