Statements that recount past events -- medical history, past symptoms, the origins of symptoms or conditions, and external causes -- can fall within the federal hearsay exception for statements made for purposes or medical diagnosis or treatment.

United States v. Udeozor, 515 F.3d 260, 267-268 (4th Cir. 2008) (upholding trial court's admission of two police recorded telephone conversations [between the victim and defendant's husband] as statements against penal....Federal Rule of Evidence of Evidence 804(b)(3) or a comparable State rule creates a hearsay exception for a statement which was at the time of its making so far contrary to the declarant's pecuniary or proprietary interest, or so far tended to subject the declarant to civil or criminal liability, or to render invalid a claim by the declarant against another, that a reasonable person in the declarant's position would not have made the statement unless believing it to be true. A statement tending to expose the declarant to criminal liability and offered to exculpate the accused is not admissible unless corroborating circumstances clearly indicate the trustworthiness of the statement.

Fed. R. Evid. 404(b) (Evidence of other crimes, wrongs, or acts "may... be admissible for other purposes, such as proof of motive, opportunity, intent, preparation, plan,....A person's other crimes, wrongs, or acts are not barred by the character rule either if they are not offered to show that person's propensity or if they are not offered to show that that person engaged in conduct on a particular occasion because of his or her propensity to engage in that sort of conduct.

United States v. Prince-Ovibo, 320 F.3d 494, pin? (4th Cir. 2003) (held, exclusion of polygraph evidence was not error; dissent: per se exclsionary rule inconstent with _Daubert_).Polygraph test results are insufficiently reliable to be admissible.