The law is disordered on the question of when a presumption in a criminal trial violates the constitutionally-mandated standard of proof beyond a reasonable doubt.

United States v. Reed, 227 F.3d 763, 767 (7th Cir. 2000) (upholding trial court's ruling to admit Simmons's prior testimony because he was unavailable).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.

McKinnon v. Skil Corp., 638 F.2d 270, 277-278 (1st Cir. 1981) (holding, in plaintiff's action for negligence and breach of warranty, that evidence of prior accidents involving defendant's saws was properly excluded because plaintiff failed to show that the accidents occurred under circumstances...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.

Reagan v. Brock, 628 F.2d 721, pin? (1st Cir. 1980).An objection ordinarily must be contemporaneous with the offer of evidence; that is, ordinarily an objection must be made after an offer of evidence is made but before the the trial court rules on the admissibility of the offered evidence.