Drunk driving prosecutions depend heavily on whether law enforcement can establish proof that the driver of the vehicle was in fact intoxicated at the time of arrest. If a police officer suspects you of drunk driving and pulls you over, there are several ways that the officer will assess whether to make an arrest for DUI, beginning with assessing how you interact with him and progressing through field sobriety tests and possibly concluding with breath or blood alcohol content testing.

At least in part because driving on public roads is considered by all 50 states to be a privilege and not a right, all states have what are known as “implied consent” laws when it comes to the administration of these tests. This does not mean that you have no choice whether to submit to something like a breath or blood test; you can refuse to give a sample, particularly if the police officer has not obtained a search warrant. Such refusal will, however, at least subject you to penalties under Oklahoma law and — if you were involved in an accident causing death or physical injury to another person — the officer may be able to have a blood sample taken from you even without first getting a warrant to do so.

The general rule: blood tests require a search warrant to be reasonable

Blood tests taken without a search warrant in particular have been the subject of disputes as to their permissibility under the U.S. Constitution because their collection involves a physical invasion of the body. Law enforcement authorities have argued that because blood alcohol content steadily declines over time after a person has finished consuming alcohol, the delays involved in obtaining a search warrant to collect a blood sample can lead to a potential loss of evidence. Drivers being compelled to provide blood samples without a warrant, on the other hand, have raised privacy concerns that the Court has taken seriously, and the reconciliation of these privacy expectations against the need to collect perishable evidence has led to the Court devising a general rule about when warrantless blood testing is permissible.

The general rule that the Court has come up with is that warrantless blood testing in is “unreasonable” when it comes to the protection of the Fourth Amendment to the U.S. Constitution (which protects individuals against unreasonable searches and seizures by the government) unless the police can demonstrate that a valid “exigent circumstance” exists.

What is an exigent circumstance?

There is no uniform or “per se” standard to define what an exigent circumstance is that justifies undertaking a search without a warrant. The Court has identified some examples of what these circumstances can be, including:

• the need to provide emergency services to a person who occupies a home, or to enter a building to extinguish a fire and to determine its cause;

• engaging in “hot pursuit” of a fleeing crime suspect; and

• to prevent the imminent destruction of evidence.

It is the last point above that police have sometimes used to claim that there is no time to get a warrant before taking a blood sample, but the Court has ruled that the metabolization of alcohol in the blood — and the resulting decline in the subject’s blood alcohol content — is not an exigent circumstance because it does not constitute an “emergency” situation that justifies foregoing the need for a search warrant.

Instead, the question of whether an exigent circumstance exists depends on a case-by-case determination. The potential loss of evidence is a factor to be considered in this determination, but it cannot automatically justify taking a warrantless blood sample.

What does this mean to you if police want to take your blood?

As we have mentioned above, under Oklahoma law refusal to comply with “implied consent” will generally mean that a blood or breath sample cannot be taken against your will, absent the death-or-injury exception (remember that you can still be subject to sanctions, though, such as a suspension of your driver’s license). Whether that statutory exception constitutes a “per se” rule that the U.S. Supreme Court has held insufficient to justify warrantless searches given its case-by-case requirement can be the subject of argument, but in other situations in which police seek to take a blood sample from you without first securing a search warrant you may want to consider refusing to consent at least long enough to contact the Oklahoma DUI Attorneys at the Hunsucker Legal Group. The HLG DUI lawyers are experienced with Oklahoma’s DUI laws and how both state and Federal courts have interpreted them.