In Commonwealth v. Williams, the defendant appealed from his convictions for murder and related offenses. At issue was the proper method – if any – for impeaching a hearsay declarant when that declarant did not testify for either party at trial. The issue turned on Pa.R.E. 806, which permits a hearsay declarant’s credibility to be impeached “by any evidence that would be admissible for those purposes if the declarant had testified as a witness.”  The trial court denied the defendant’s request to call a witness to testify to the declarant’s prior inconsistent statement but offered a tepid cautionary instruction as to the declarant’s relevance to the case. The Pennsylvania Superior Court held that the trial court erred in precluding the defendant from calling his proffered witness. But the Supreme Court then found that the error was harmless beyond a reasonable doubt. The Court also held that the trial court properly admitted into evidence the defendant’s letter sent, which he sent from prison before trial. The letter contained an image similar to an image found on a shirt he allegedly discarded while fleeing the police.