John Paul Stevens

“ It is natural for jurors to be skeptical of self-serving testimony by the defendant. Testimony by a witness said to be independent has the greater potential to deceive. And if a defense witness can present false testimony with impunity, the jurors may find the rest of the prosecution's case suspect, for ineffective and artificial cross-examination will be viewed as a real weakness in the state's case. Jurors will assume that if the prosecution had any proof the statement was false, it would make the proof known. The majority does more than deprive the prosecution of evidence. ”

“ Also missing from the majority's analysis is the almost certain knowledge that the testimony immunized from rebuttal is false. The majority's apparent assumption that defense witnesses protected by today's rule have only truthtelling in mind strikes me as far too sanguine to support acceptance of a rule that controls the hard reality of contested criminal trials. The majority expresses the common sense of the matter in saying that presentation of excluded evidence must sometimes be allowed because it "penalizes defendants for committing perjury." ”

“ A witness who is not on trial faces a far different calculus than one whose testimony can mean the difference between acquittal and a prison sentence. He or she will think long and hard before accepting a defendant's invitation to knowingly offer false testimony that is directly contradicted by the State's evidence. The dissent ignores this "hard reality," post, at 326, in presuming that a defense witness will offer false testimony when that testimony is immunized from rebuttal at trial. ”

“ While the dissent assumes false testimony or, at least, faulty recollection with respect to defense witnesses, it is unwilling to entertain the same assumption with respect to the prosecution's witnesses. The evidentiary issue in this case involves the testimony of a police officer about a statement that he allegedly heard the defendant make at the time of his arrest. An officer whose testimony provides the foundation for admission of an oral statement or physical evidence may be influenced by his interest in effective law enforcement or may simply have faulty recollection. ”

“ The State always has a strong interest in the truth-seeking function. The proper question, however, is whether the admission of the illegally obtained evidence in this case would sufficiently advance the truth-seeking function to overcome the loss to the deterrent value of the exclusionary rule. With respect to this issue, the dissent overestimates the benefit of the exclusionary rule even to the defendant bent on presenting perjured testimony and exaggerates the injury that exclusion of unlawfully obtained evidence causes to the truth-seeking function. ”

“ Moreover, in cases involving the suppression of physical evidence, which the majority's rule must also govern, the reliability of the suppressed evidence itself will not be in question since the evidence is not testimonial. ”