In Doan v. Commonwealth, 15 Va. App. 87, 100, 422 S.E.2d 398, 405 (1992), the Court explained that, "for a witness to be deemed unavailable, the proponent of the evidence bears the burden of proving . . . that one of the following conditions exists: (1) The declarant is dead; (2) The declarant is too ill to testify; (3) The declarant is insane; (4) The declarant is absent from the state and the party is unable to obtain the declarant's deposition; (5) The party has been unable by diligent inquiry to locate the declarant; (6) The declarant cannot be compelled to testify; (7) The opposite party has caused the declarant's absence." Doan, 15 Va. App. at 101, 422 S.E.2d at 406. The Court said that "'the witness who is now testifying as to what was said at the former trial must be able to do so with reasonable accuracy.'" Id. at 100, 422 S.E.2d at 405.