“IMPEACHMENT” USE OF ILLEGALLY OBTAINED EVIDENCE
Although the Federal “Exclusionary Rule” prevents the admission of illegally obtained evidence in the case in chief, it does not preclude the use of such “tainted” evidence for impeachment purposes where the accused testifies in his own behalf. Harris v. New York, 401 U.S. 222 (1971) [confession obtained in violation of Miranda, admissible on cross-examination to impeach accused]; Mincey v. Arizona, 437 U.S. 385 (1978) [involuntary statements cannot be used even for impeachment purposes]; U.S. v. Havens, 446 U.S. 620 (1980) [evidence obtained as result of illegal search may be used to impeach statement elicited on cross-examination of accused who testified in his own behalf]. However, the Supreme Court has held that evidence illegally obtained from the accused may not be used to impeach other defense witnesses. James v. Illinois, 493 US 307, 107 L.Ed.2d 676, 110 S.Ct. 648 (1990).
“The [Illinois Supreme] Court reasoned that, in order to deter the defendant from engaging in perjury ‘by proxy’, the impeachment exception to the exclusionary rule ought to be expanded to allow the State to introduce illegally obtained evidence to impeach the testimony of defense witnesses other than the defendant himself…
‘There is no gainsaying that arriving at the truth is a fundamental goal of our legal system.’ But various constitutional rules limit the means by which government may conduct this search for truth in order to promote other values embraced by the Framers and cherished throughout our Nation’s history. ‘Ever since its inception, the rule excluding evidence seized in violation of the Fourth Amendment has been recognized as a principal made of discouraging lawless police conduct…[W]ithout it the constitutional guarantee against unreasonable searches and seizure would be a mere ‘form of words.” The occasional suppression of illegally obtained yet probative evidence has long been considered a necessary cost of preserving overriding constitutional values: ‘[T]here is nothing new in the realization that the Constitution sometimes insulates the criminality of a few in order to protect the privacy of us all.
“Expanding the class of impeachable witnesses from the defendant alone to all defense witnesses would create different incentives affecting the behavior of both defendants and law enforcement officers… More significantly, expanding the impeachment exception to encompass the testimony of all defense witnesses likely would chill some defendants from presenting their best defense — and sometimes any defense at all… inadmissibility of illegally obtained evidence must remain the rule, not the exception.”
James v. Illinois, 493 U.S. 307, 107 L.Ed.2d 676, 110 S.Ct. 648 (1990)[citations omitted].