U.S. Supreme Court Rules in Favor of the Constitution: Landmark DUI Blood Test Case Decided

On April 17, 2013, The U.S. Supreme Court ruled on Missouri v. McNeely, siding with the lower courts’ decisions in a 5-4 ruling to suppress DUI evidence from being used against the defendant.

The case involved a DUI stop, following a moving traffic violation. After questioning, the driver was arrested for suspicion of DUI, after he refused to submit to a DUI breath and blood test.

Following the arrest he was transported to a nearby hospital where a DUI blood test was taken by a lab technician, at the direction of the police officer. The blood test was conducted without the driver’s consent, and in absence of a warrant. The police officer made no attempt to obtain a warrant to collect the blood for the DUI investigation.

The blood test concluded that the driver’s Blood Alcohol Content (BAC) was well above the legal limit of 0.08%. The driver was subsequently charged with Driving While Intoxicated (DWI).

The defendant’s attorney moved to suppress the DUI blood evidence on the basis that it was a violation of his Fourth Amendment Constitutional Rights against unlawful search and seizure. The lower court agreed to suppress the evidence.

The law allows for exceptions that may apply where blood test may be conducted without a warrant and in absence of consent, such as in the case of an emergency, or to avoid destruction of evidence. However, the lower court did not feel any exceptions applied. The trial court recognized that the suspect’s BAC was dissipating, but that no other factor existed to suggest that the blood needed to be taken without consent or warrant due to emergency circumstances, also known as exigent circumstances.

After the Missouri Supreme Court sided with the lower court to suppress the evidence, the State appealed to the U.S. Supreme Court. The high court recognized that the process of human metabolism of alcohol in the bloodstream that results in ensuing loss of evidence is always a factor that must be considered when deciding if a warrant is required. But that each case should be decided on its own merits, otherwise every blood test case would be felt to fall within exigent circumstances.

The U.S. Supreme Court was also of the opinion that resources such as a State’s “Implied Consent” Laws, and other non-invasive forms of DUI investigative tools were readily available in states for police that allowed police to non-invasively investigate impaired driving and assist with identification of other circumstances that may be considered exigent factors.

Impact of the US Supreme Court Ruling in Arizona and Implied Consent

The ruling will not likely impact current Arizona Laws that exist now. In Arizona, the police require a warrant to proceed with a blood test, unless the suspect otherwise consents to the blood test. However, under the Arizona Implied Consent laws Law of A.R.S. 28 – 1321, any motorist driving in the state is considered to inherently provide consent at the request of the police to conduct a DUI breath or blood test as a part of the DUI investigation. If they refuse, whether they are impaired or not, they will be subject to an automatic suspension of their driving privileges.  In addition, they may be arrested for suspicion of DUI and taken into custody, until a blood test warrant is received from a judge on call in that jurisdiction. Implied Consent laws are intended to penalize drivers who refuse to cooperate in the investigation. The same exceptions to the warrant apply in Arizona, to arrest warrants in absence of consent including exigency circumstances, or imminent threat of destruction of evidence. 

The ruling however, does enforce the fact that any driver who refuses a blood test, cannot automatically be forced to submit to one without a warrant simply because of the body’s ability to reduce BAC levels over time. This natural function is not to be considered an emergency with no other factors involved. This lends strength and further enforcement of the 4^th Amendment Rights under the US Constitution as well as Arizona Constitution.