Experienced Criminal Defense Attorney Dedicated To Protecting Your Rights
Photo of New York City

Warrantless Alcohol Blood Tests Declared Unconstitutional by the Supreme Court

The United States Supreme Court recently issued an opinion in a case, Missouri v. McNeely, which will affect the rights of those accused of drunk driving. The issue that was decided in the case was whether law enforcement officers need a warrant before compelling those suspected of driving while intoxicated to submit to a blood alcohol test.

Background of case


The case arose when a man was pulled over for speeding on a highway in Missouri. During the stop, the officer noticed that the driver exhibited signs of intoxication such as slurred speech, bloodshot eyes and the smell of alcohol. Based on his observations, the officer asked the man to submit to a battery of field sobriety tests, which were performed poorly. The driver also refused a Breathalyzer test, so the officer transported the man to the hospital and had staff take a sample of the man’s blood over his objections.

The blood sample, which was taken about 25 minutes after the stop, showed that the driver’s blood alcohol level was .15 percent, almost twice the legal limit. The driver was then arrested for DUI.

At trial, the man argued that the results of the blood test should be suppressed, as the officer’s failure to get a warrant was a violation of his Fourth Amendment rights against unreasonable searches and seizures. He further argued that there were not “exigent circumstances”-emergency situations that would excuse the failure to get a warrant before conducting the search. However, the state argued that alcohol in the bloodstream is metabolized quickly, so police were excused from getting a warrant, because any delay would have led to a destruction of evidence.

The Missouri Supreme Court ultimately decided that a warrant was required and excluded the results of the blood test from evidence. State prosecutors appealed the decision to the U.S. Supreme Court.

Generally, warrants are required

The U.S. Supreme Court, in a 5-4 decision agreed with the Missouri Supreme Court. The court ruled that, as a general rule, the natural dissipation of alcohol in the blood stream does not automatically excuse police from getting a warrant before taking a blood sample.

However, the court did allude to situations where the taking of a blood sample without a warrant would be constitutionally permissible. Still, the court said that such situations should be determined on a case-by-case basis based on the surrounding circumstances. Situations where a warrant could not practically be obtained in time to preserve the ability to collect reliable evidence would likely be instances where a warrant would not be required. However, the court noted that in this technological age where a judge can be reached almost immediately, such instances are likely few and far between.

Speak to an attorney

This case illustrates the lengths that law enforcement across the nation will go to make a bust. If you are accused of drunk driving, contact an experienced criminal defense attorney who can ensure that your rights are respected and protected.