quality:correction, structural:expansion, information:classification
Contradiction

Another example is more extreme. Suppose the defendant is on trial for possession of heroin. The defendant's testimony will naturally deny possessing the particular drug. Suppose the defendant foolishly testifies on direct examination, "In fact, I've never possessed heroin in my life." The prosecutor can then, on cross-examination, impeach him with an exhibit of heroin seized on an unrelated occasion even if it was seized in violation of his Fourth Amendment rights. The Walder decision led to a ruling that a defendant can be impeached by his confession even if the confession was obtained in violation of his Miranda rights. Harris, in turn, led to a decision allowing similar impeachment by physical evidence that had been suppressed in the same case as having been seized from defendant in violation of his Fourth Amendment rights.