Forgotten Constitutional History

The Warren Court greatly expanded various constitutionally-rooted exclusionary rules that serve purposes other than truthseeking, purposes such as deterrence of excessive police violence and unreasonable invasions of privacy. There was a great outcry in some quarters against the Court's expansion of such rules in the 1960s: It was often said that the Supreme Court had forgotten that the fundamental purpose of a criminal trial is to determine the truth.

The outcry had an effect: In the last two or three decades the Supreme Court has dramatically limited the scope of nontruthseeking constitutional exclusionary rules.

But guess what? When almost no one was looking, the Supreme Court also limited the reach of constitutional exclusionary rules whose primary purpose is the enhancement of the priority of truth -- factfinding accuracy -- in the criminal process.

So the upshot for the Warren Court's critics was this: Heads we win, tails you lose. Justice Marshall, dissenting in Manson v. Brathwaite, 432 U.S. 98 (1976), noticed this irony as long ago as 1976. Complaining of the Court's relaxation of its rules against the use of unduly suggestive eyewitness identifications, he wrote:

[O]ther exclusionary rules have been criticized for preventing jury consideration of relevant and usually reliable evidence in order to serve interests unrelated to guilt or innocence, such as discouraging illegal searches or denial of counsel. Suggestively obtained eyewitness testimony is excluded, in contrast, precisely because of its unreliability and concomitant irrelevance. Its exclusion both protects the integrity of the truthseeking function of the trial and discourages police use of needlessly accurate and ineffective investigatory methods.

It is time for the Court to reverse course once again. This time the Court should focus on developing due process principles that protect the integrity of factfinding in the criminal process.