Does the trial court have an added dollop of discretion or does it have absolute or almost almost absolute discretion when assessing the relevance or the possibly unduly prejudicial nature of visual and demonstrative evidence?

United States v. Avants, 367 F.3d 433, 444-445 (5th Cir. 2004) (upholding trial court's admission of the 1966 preliminary hearing testimony through Rule 804(b)(1) because the "[defendant] has not presented any reason why....The hearsay exception for prior testimony applies in a criminal case only if the if the party against whom the testimony is now offered had an opportunity and similar motive to develop the testimony in the prior proceeding by direct, cross, or redirect examination. The exception applies in a civil action or proceeding only if the party against whom the testimony is now offered or a predecessor in interest had an opportunity and similar motive in the prior proceeding to develop the testimony by direct, cross, or redirect examination.

Fed. R. Evid. 807 (a "statement not specifically covered by Rule 803 or 804" must have "equivalent circumstantial guarantees of trustworthiness" if the statement is to be admissible under Rule 807).A statement is admissible under the hearsay exception created by Federal Rule of Evidence 807 or a comparable State rule only if circumstantial evidence shows that the affected statement is as trustworthy as the statements that are made admissible by the hearsay exceptions created by Federal Rules of Evidence 803 and 804 or by comparable State rules.

Huddleston v. United States, 485 U.S. 681, 690 (1988) ("In determining whether the Government has introduced sufficient evidence to meet Rule 104(b), the trial court neither weighs credibility nor makes a finding....The trial court's assessment of sufficiency of the evidence of another crime, wrong, or act offered for a nonpropensity purpose under the second sentence of federal Rule of Evidence 404(b) cannot rest on the trial court's assessment of the credibility of a witnesses or witnesses.