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Case Bulletin – United States Supreme Court Holds that Warrantless Blood Draws Upon DUI Arrests are Unconstitutional

On June 23, 2016, the United States Supreme Court issued a 7-1 decision in the matter of Birchfield v. North Dakota, 579 U.S. ____ (2016), wherein the Court considered three separate challenges to “implied consent” laws, which require suspected DUI drivers to undergo a breath or blood test, without a warrant, or face prosecution for a refusal as a condition of operating a motor vehicle.   The Court granted certiorari to determine whether motorists lawfully arrested for drunk driving may be convicted of a crime or otherwise penalized for refusing to take a warrantless chemical test measuring the alcohol in their bloodstream.


The Court considered the issue of whether the search incident to arrest doctrine, which permits a limited warrantless search of the person and the area within his immediate control when an individual  is taken into custody, applies to alcohol testing.  In doing so, it considered the degree to which the testing intruded on the individual’s privacy and the degree to which it is needed for the promotion of legitimate government interests.


The Court found that breath tests do not implicate serious privacy concerns because capturing the breath expelled from the body is not a significant intrusion.  Blood tests, in contrast, were found to be significantly more intrusive.  The Court also noted that the breath can only be used to learn alcohol levels, whereas a blood sample can provide significantly more information about a person.  The Court further found that the states have a “paramount” interest in maintaining the safety of the public highways from drunk drivers.


Ultimately, the Court declined to require a warrant for breath testing, holding that the Fourth Amendment permits warrantless breath tests incident to arrests for drunk driving because the impact of a breath test on privacy is slight and the need for the testing is great.  However, the Court determined that blood tests are significantly more intrusive, and that their reasonableness must be judged in light of the availability of a less invasive alternative.  As such, it determined that a breath test, but not blood, may be administered as a warrantless search incident to a lawful arrest for DUI.   The Court further held that a motorist is deemed to have provided “implied consent” only to conditions of driving that are reasonable, and that a motorist cannot be deemed to have consented to a blood test on pain of additional criminal sanctions.


Note that while all of the matters before the Court involved testing for the presence of alcohol, the decision would appear to apply to warrantless DUI blood testing for the presence of drugs, as well.  The Court specifically noted that blood testing serves the additional purpose of detecting when someone is under the influence of drugs, but indicated that law enforcement has other measures available at their disposal when drugs are suspected, including seeking a warrant for blood testing.