Implied consent laws generally provide that a motorist may be penalized for refusing to be tested for alcohol if there is sufficient reason to believe the motorist is operating a motor vehicle in violation of drunk-driving laws. The results of these tests are often essential evidence in a criminal DUI prosecution. Because of increased public outcry over drunk driving, criminal penalties for DUI/DWI have increased. In addition, these increased penalties have given drivers an incentive to refuse a test. In a decision handed down June 23, the U.S. Supreme Court, in a trio of cases, refused to find these implied consent laws were contrary to the 4th Amendment.
The Court acknowledged that blood-alcohol testing constituted a search under the Fourth Amendment; and since each of the defendants had been arrested for driving under the influence, the court based its analysis on the question of whether the testing was a lawful “search-incident-to-arrest”. The Court’s first consideration was privacy. In the case of a search-by-Breathalyzer, the court explained, “Humans have never been known to assert a possessory interest in or any emotional attachment to any of the air in their lungs. [A]ll the air that is breathed into a breath analyzing machine, . . . sooner or later would be exhaled.” Id. at *21. In contrast, however, the Court observed that when blood is drawn for testing, different considerations apply, since blood could be used for purposes not intended. Therefore, blood testing does infringe on privacy interests.
The second consideration for the court was whether the test furthered a legitimate government interest. Clearly, the desire to rid the highways of drunk drivers is a compelling interest. Justice Sotomayor, in a partial dissent, argued that, the search-incident-to-arrest could be performed after obtaining a warrant. The Court explained that “requiring a warrant for BAC testing in every case in which a motorist is arrested for drunk driving would  impose [a] great burden on the police [and] courts. . . . If a search warrant were required for every search incident to arrest that does not involve exigent circumstances, the courts would be swamped. And even if we arbitrarily singled out BAC tests incident to arrest for this special treatment, . . . the impact on the courts would be considerable” with more than 1.1 million arrests in 2014 alone. Id. at 27. The majority also explained that there was a need for guidance useful to law enforcement in cases such as these. By offering anything less than a universal rule, the Court would be doing a disservice. “If police are to have workable rules, the balancing of the competing interests must in large part be done on a categorical basis—not in an ad hoc, case-by-case fashion by individual police officers.” Id. at *26.
The Court has created a rule that is certainly easy to put into effect. At the same time, it gives law enforcement an incentive to use breath tests for alcohol instead of the more accurate blood tests. Whether this makes any practical difference for DUI prosecutions remains to be seen.