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.