Knock, Knock

The Supreme Court finds a disturbing way to issue a reasonable opinion.

THE TROUBLING feature of the Supreme Court's decision last week in the case of Hudson v. Michigan is not the court's holding. The court ruled that when police officers fail to clearly identify themselves and then wait briefly before searching the premises with a valid warrant, the evidence collected need not be excluded from a suspect's trial. Notwithstanding the hysterical response of some commentators, this is not an outrageous position. What is troubling is the reasoning by which the court reached its result, which seems to challenge far more broadly the long-standing rule that evidence obtained illegally cannot be used in criminal proceedings.

We can't get too worked up that the court refused to suppress evidence seized by Michigan police in Booker T. Hudson Jr.'s case. They had a lawful warrant to search his home. They announced their presence. The trouble is only that they then waited between three and five seconds, instead of 15 to 20, before entering. When they entered, they found a loaded gun and lots of drugs -- evidence he then asked the court to suppress.

The "knock-and-announce rule" has its origins in the 13th century, but the court has considered it a constitutional requirement only since 1995. And the question of whether violations of it trigger the exclusionary rule has never been resolved. So the 5 to 4 decision last week is less a rollback of the exclusionary rule than a refusal to extend it. The refusal has a certain logic. The idea of the exclusionary rule, as Justice Antonin Scalia explained for the majority, is not merely to deter government misbehavior but also to prevent police from using evidence they should not have obtained in the first place. In Mr. Hudson's case, officers didn't get any evidence they would not have gotten anyway.

Had Justice Scalia stopped there, his opinion would be debatable but not objectionable. But he didn't stop. He went on to argue that the court should not extend the exclusionary rule to this situation because of the rule's "substantial social costs" -- that is, its tendency to free guilty people. He argued that civil lawsuits, unavailable when the court first allowed suppression of illegally seized evidence, provide ample deterrence for such misconduct now. He also argued that police behavior is so improved from earlier eras that the exclusionary rule is not necessary here. These arguments, as Justice Stephen G. Breyer argued pointed out in dissent, seem to attack the very foundations of the exclusionary rule -- which has existed since 1914.

Justice Anthony M. Kennedy joined the bulk of the majority opinion but wrote separately to emphasize that the vitality of the court's precedents was "not in doubt." That he had to say so emphasizes the potential scope of Justice Scalia's arguments. The court's two new justices both joined Justice Scalia's opinion. One of them, Chief Justice John G. Roberts Jr., recently gave a speech in which he emphasized the importance of deciding cases "on the narrowest possible ground." That's not what happened here.