Holding: In drunk-driving investigations, the natural dissipation of alcohol in the bloodstream does not constitute an exigency in every case sufficient to justify conducting a blood test without a warrant.
Judgment: Affirmed, 5-4, in an opinion by Justice Sotomayor on April 17, 2013. Justice Sotomayor announced the judgment of the Court and delivered the opinion of the Court with respect to Parts I, II-A, II-B, and IV, in which Justice Scalia, Justice Kennedy, Justice Ginsburg, and Justice Kagan joined, and an opinion with respect to Parts II-C and III, in which Justice Scalia, Justice Ginsburg and Justice Kagan joined. Justice Kennedy filed an opinion concurring in part. Chief Justice Roberts filed an opinion concurring in part and dissenting in part, in which Justice Breyer and Justice Alito joined. Justice Thomas filed a dissenting opinion.