News & Blog

Court Rules on Warrantless BAC Tests

July 21, 2016 • DUI Defense

In a drunk driving case, a prosecutor has to show that a driver was impaired by drugs, alcohol or a combination of the two. Unless the prosecutor can prove intoxication beyond a reasonable doubt, a DUI defendant should be acquitted.

That said, in an effort to try to ensure that prosecutors have the evidence they need, the police attempt to obtain a measurement of a driver's blood alcohol concentration (BAC). Blood tests, breathalyzer tests, and urine tests can all be used to measure alcohol (and sometimes drugs) in a person's system.

Police and prosecutors really want the results of scientific testing to demonstrate a driver's BAC because it can be easier for them to get a conviction with this powerful evidence. Defendants, however, can benefit from not having this type of evidence introduced. 

Individuals who are arrested for impaired driving need to talk with Tallahassee drunk driving defense lawyers to find out whether or not they can keep scientific evidence about their BAC level from being used against them.  

Supreme Court Looks at Forced Blood Testing

Law enforcement officials and state lawmakers have tried a number of tactics in recent years to try to make sure they can get a driver's BAC tested. Often, the creative approaches taken by police and prosecutors have resulted in cases being challenged in court. The good news is that courts seem to be protecting the rights of defendants.

In the case of Missouri v. McNeely, law enforcement officials forced a driver to submit to a blood test without a warrant. When the admissibility of the test was challenged, they argued there were “exigent circumstances,” claiming that they had to force the defendant to take the test since the body was metabolizing the alcohol and destroying the evidence.

The case made it all the way to the Supreme Court, which ruled that this was not an acceptable reason to compel a warrantless search. The search violated the defendant’s Fourth Amendment protections.

McNeely effectively meant that police could no longer force blood tests. They either had to get a warrant or the defendant had to consent to take the test. Soon, however, another problem arose: 13 states had laws making it a crime to refuse a blood test, as long as there was reasonable cause to suspect impairment. This meant drivers had to “consent” to take the warrantless test, and if they didn't, they could face criminal charges.

This was challenged too, and the court recently ruled on three consolidated cases addressing the issue. In Birchfield v. North Dakota, the court found that, while it was okay to criminalize a refusal to submit to a breathalyzer, it was not okay to criminalize a refusal to submit to a blood test.

The decision was based on the strong interest that states have in preventing drunk driving (which justifies a required breath test), as well as the right of a driver not to be subject to a much more invasive blood test.

Defendants need to understand the rights they have to be free from unlawful searches, and should talk with a skilled drunk driving attorney to see if they can prevent evidence that has been collected from being used against them if the police acted inappropriately.