In the course of refusing to exclude evidence obtained through an illegal no-knock search in Hudson v. Michigan, Justice Scalia claimed that the rule was obsolete:
Another development over the past half-century that deters civil-rights violations is the increasing professionalism of police forces, including a new emphasis on internal police discipline.The logic of this argument (like much of Scalia's opinion) is dubious. If police forces increased their professionalism in the wake of the requirements established by the Warren Court, including the application of the exclusionary rule to the states, this doesn't strike me as a good reason to get rid of said requirements.
At any rate, Radley Balko finds an example of the professionalism that allegedly allows the Court to get rid of negative disincentives:
Last week, police stormed Calvo’s home without knocking, shot and killed his two black labs, and questioned him and his mother-in-law at gunpoint over a delivered package of marijuana that police now concede may have been intended for someone else.It's good that the Supreme Court has encouraged this kind of sterling police work!The Washington Post reports that the police didn’t even bother to get a no-knock warrant, which means the tactics they used were illegal.
To add an additional point, it is true (as its critics will point out) that after the fact the exclusionary rule does not provide a remedy in cases where evidence isn't found. But that doesn't mean that the innocent derive no benefits from the rule. If the state knows that it can't use illegally obtained evidence, it has a strong disincentive not to break the law in the first place.
--Scott Lemieux