The permissible evidentiary bases for scientific and expert opinion

United States v. Geiger, 263 F.3d 1034, 1038-1039 (9th Cir. 2001) (upholding trial court's admission of arresting officer's prior testimony at the federal suppression hearing because "[u]nder Rule 804(b)(1), prior testimony....If the declarant is unavailable, Federal Rule of Evidence 804(b)(1) or a comparable State rule creates a hearsay exception for testimony given as a witness at another hearing of the same or a different proceeding, or in a deposition taken in compliance with law in the course of the same or another proceeding, if the party against whom the testimony is now offered, or, in a civil action or proceeding, a predecessor in interest, had an opportunity and similar motive to develop the testimony by direct, cross, or redirect examination.

United States v. Estrada, 430 F.3d 606, 615-620 (2d Cir. 2005) (important case; in the course of discussing whether details of a Rule 609(a)(1) conviction should ordinarily be admissible for purposes of impeachment, court makes a variety of observations about the role played for purposes of...If a conviction is offered for impeachment under Federal Rule of Evidence 609(a)(1), the conviction must be probative of the truthfulness of the target of the proposed impeachment, the witness sought to be impeached.

United States v. Porter, 986 F.2d 1014, 1018 (6th Cir. 1993) (convictions for conspiracy to possess and distribute cocaine, receive explosives, forcing a minor to help avoid capture, receiving explosives while using controlled substance, and distributing drugs to persons under 21; defendant asserted...Both the communicating spouse and the spouse receiving a marital secret are holders of the marital secret privilege (the confidential marital communications privilege) with respect to that communication