On Wednesday, in Missouri v McNeely, the U.S. Supreme Court ruled 8-1 that involuntary blood test of a suspected drunk driver requires a search warrant in most cases. While the justices did not provide any clear guidance as to situations where a search warrant is necessary for administering an involuntary blood test, they agreed, in the instant case, that a blood test made without a warrant violates rights granted under the Fourth Amendment to the U.S. Constitution.
In the instant case, the suspected drunk driver, Tyler McNeely, police made an involuntary blood test without warrant, after McNeely refused to take a breathalyzer test.
The decision was fairly confused in that, though the ruling went 8-1 in McNeely's favour, only three of the nine judges concurred fully with the majority opinion written by Justice Sonya Sotomayor.
Justice Clarence Thomas dissented and wrote an opinion in dissent.
Justice Anthony Kennedy wrote a separate opinion, though agreeing largely with the majority opinion.
Chief Justice John Roberts wrote an opinion which partly concurred with the majority opinion. Roberts was joined by Justice Stephen Breyer and Justices Samuel Alito.
Sotomayor observed in her opinion that while the determination of whether to administer a blood test or not "will no doubt vary depending on the circumstances," nevertheless, the police needs to provide reasons "sufficient to justify conducting a blood test without a warrant."
In the instant case, Sotomayor noted, there was nothing to prevent the officer from seeking a warrant, and the state did not argue that it lacked time to obtain a warrant before evidence was lost.
In his opinion, Justice Kennedy said that the case gave the court too little opportunity to provide a more comprehensive framework for the police to follow.
In a similar tone, Roberts noted in his opinion that the conclusions of the court would likely leave officers confused about how to avoid violating the Fourth Amendment and that police officers need seek a warrant, if they have the time in hand, before evidence is lost.
The ruling, in effect, restricts the ability of the police to administer an involuntary blood test without a warrant.