Prior acts of a witness may be elicited during the interrogation of the witness to impeach the truthfulness of a witness, but the acts so inquired into must in fact be probative of truthfulness.

Christopher Phelps & Associates, LLC v. Galloway, 477 F.3d 128, 137 (4th Cir. 2007) (holding, in plaintiff architectural firm's action against defendant for copyright infringement, that the trial court properly admitted the Mecklenburg County....An exception to the hearsay rule applies to the following records of government offices and agencies: (A) public records that set forth the activities of the government office or agency; (B) public records that set forth observations that a government office or agency was required to make and report but this exception does not apply in criminal cases to observations of police officers and other law enforcement personnel; or (C) in civil actions and proceedings and in criminal cases when offered against the government, factual findings resulting from an investigation made pursuant to authority granted by law, unless the sources of information or other circumstances indicate the untrustworthiness of such findings.

Reilly v. City of Atlantic City, 532 F.3d 216, 230 (3d Cir. 2008) (quoting from Catletti ex rel. Estate of Catletti v. Rampe, 334 F.3d 225, 229-30 (2d Cir.2003) with approval : "paramount importance of judicial truth-seeking").Although factors and purposes other factfinding and accurate factfinding influence and constrain proof and the law of evidence, factfinding and accurate factfinding are essential purposes of the process of proof and the law of evidence; without these last two purposes, the process of proof and the law of evidence would not exist in a recognizable form.

McEuin v. Crown Equipment, Corp., 328 F.3d 1028, 1034-1035 (9th Cir. 2003) (holding, in plaintiff forklift operator's action against defendants manufacturer and distributor for product liability, that evidence of military forklift....Hearsay is a statement that (i) is made other than at the trial or proceeding at which it is offered and (ii) is offered to prove the truth of the matter asserted by the maker of the statement, the declarant.