Breath Tests, Implied Consent and the Exclusionary Rule in Arizona DUI Cases

The most common type of chemical test performed by police in Arizona DUI cases is breath testing. Breath testing measures the amount of alcohol in a person’s breath and converts the figure to blood-alcohol content. Police prefer breath testing in many cases because it is faster and less expensive than blood or urine testing.

Practically speaking, absent physical coercion, breath testing cannot be performed without a driver’s consent. However, under Arizona’s implied consent statute, any motorist who “operates a motor vehicle in this state gives consent … to tests of the person’s blood, breath, urine or other bodily substance for the purpose of determining alcohol concentration or drug content” if they are arrested for suspicion of driving under the influence of drugs or alcohol. Thus, while a motorist can physically refuse to provide a sample, they do not have the legal right to do so. Of course, to rely on the implied consent statute, police must provide a defendant with their rights and the consequences of refusal.

What Happens When Police Don’t Follow the Law?

Generally speaking, when police obtain evidence obtained through improper, illegal, or unconstitutional means, that evidence must be suppressed. This concept is referred to as the exclusionary rule, and is a judicially-created doctrine to deter improper police conduct. Indeed, the United States Supreme Court has held that when a defendant’s blood was taken without a warrant or his consent, the blood-test results were inadmissible. The Court based its holding on the inherent privacy interest a person has in their blood and the intrusive means of obtaining a blood sample. However, in a subsequent case, the Court distinguished between taking a defendant’s blood and using a breath sample. This left an open question regarding the admissibility of breath-test evidence that was obtained in violation of the implied consent statute.

In a 2018 case, an Arizona appellate court issued an opinion allowing the use of breath-test evidence that was obtained improperly. In that case, the court found that the warnings provided to the defendant were coercive, and that his blood was taken in violation of the implied consent statute. However, relying on the distinction between blood and breath evidence, the court concluded that the exclusionary rule does not apply to a violation of the implied consent statute.

The court explained that because the exclusionary rule in Arizona is judicially created, courts are able to craft exceptions. In this case, the court reasoned that the exclusionary rule was created to deter violations of a defendant’s constitutional rights and because there is a diminished privacy interest in a person’s breath, the Fourth Amendment is not implicated.

Thus, under the court’s ruling, even illegally obtained breath samples may be used. However, it is important to note that not all illegally obtained breath samples will be admissible. Samples that were taken in violation of a defendant’s constitutional rights will still be suppressible.

Have You Been Arrested for an Arizona DUI?

If you have recently been arrested for drunk driving in Arizona, you should contact the Law Office of James E. Novak as soon as possible. Attorney Novak is an experienced Arizona DUI defense attorney who routinely handles all types of DUI cases and is familiar with this evolving area of law. To learn more about how Attorney Novak can help you defend against the charges you are facing, call 480-413-1499 to schedule a free consultation today.

Additional Resources:

• Missouri v. McNeely
• Birchfield v. North Dakota

Other Articles of Interest from The Law Office of James Novak’s Phoenix DUI Blog: How Can Someone Fight an Arizona DUI Charge?, Phoenix DUI Law Blog, January 24, 2019

Are Arizona DUI Checkpoints Legal?, Phoenix DUI Law Blog, February 12, 2019