To prove the contents of a thing to which the best evidence requirement applies, the original of the thing must be introduced in evidence.

Davis v. Alaska, 415 U.S. 308, pin? (1974) (held, criminal defendant's constitutional right of confrontation under the circumstances overrides state statute making confidential a juvenile court's adjudication giving juvenile -- and witness against accused -- probationary status).A nonconstitutional privilege sometimes must yield to a criminal defendant's Sixth Amendment right to confront and cross-examine an adverse witness in a criminal trial. A nonconstitutional privilege privilege may have to yield to a criminal defendant's Confrontation Right when the privilege shields evidence or facts (particularly evidence or facts showing bias) that have significant probative value on the credibility of an adverse witness in a criminal trial who testifies about material facts in issue.

United States v. McCellan, 868 F.2d 210, 214 (7th Cir. 1989) (upholding trial court's admission of the testimony of defendant's ex-wife from the 1986 adversary proceeding in bankruptcy because his ex-wife was unavailable....For purposes of the hearsay exceptions created by Federal Rule of Evidence 804 or a comparable State rule a declarant is "unavailable" within the meaning of Rule 804(b) or a comparable State rule if the declarant is unable to be present or to testify at the hearing because of death or then existing physical or mental illness or infirmity; but a declarant is not "unavailable" if the declarant's absence is due to the procurement or wrongdoing of the proponent of a statement for the purpose of preventing the witness from attending or testifying.

Hayes v. Larsen's Mfg. Co., 871 F. Supp. 56, 58 (D. Me. 1994) (dictum: "In determining the apparent risk in a negligence action, the Court may consider the evidence, or lack thereof, of other similar injuries with respect to the product in question. Such a lack of "evidence of other similar accidents or...When offered in civil actions, other similar events generally do not constitute character, or propensity, and are therefore not barred by the character rule, which prohibits the use of a person's character or propensity to show that person's conduct.