Evidence of a criminal or wrongful act apart from the act that at issue at trial Is not barred by the prohibition against circumstantial use of character if intent, knowledge, mistake, or accident is a legally-material factual issue, the opposing party suggests the non-existence of knowledge or urges mistake or accident as a defense, and evidence of another crime, wrong, or act is offered to prove the knowledge or the absence of mistake or accident by a criminal defendant or other person.

United States v. McGuire, 307 F.3d 1192, 1205 (9th Cir. 2002) (upholding trial court's ruling which determined witness as unavailable under Rule 804(a)(4) and admitted her prior testimony because "risks in late pregnancy,....For purposes of the hearsay exceptions created by Federal Rule of Evidence 804 or a comparable State rule a declarant is "unavailable" within the meaning of Rule 804(a) or a comparable State rule if the declarant (1) is exempted by ruling of the court on the ground of privilege from testifying concerning the subject matter of the declarant's statement; or (2) persists in refusing to testify concerning the subject matter of the declarant's statement despite an order of the court to do so; or (3) testifies to a lack of memory of the subject matter of the declarant's statement; or (4) is unable to be present or to testify at the hearing because of death or then existing physical or mental illness or infirmity; or (5) is absent from the hearing and the proponent of a statement has been unable to procure the declarant's attendance (or in the case of a hearsay exception under subdivision (b)(2), (3), or (4) of Rule 804(b) or a comparable State rule, the declarant's attendance or testimony) by process or other reasonable means; but a declarant is not "unavailable" if such exemption, refusal, claim of lack of memory, inability, or absence is due to the procurement or wrongdoing of the proponent of a statement for the purpose of preventing the witness from attending or testifying.

United States v. Gilbert, 668 F.2d 94, 97 (2d Cir. 1981) (holding that evidence of an earlier SEC civil consent decree signed by defendant was admissible "to show that [defendant] knew of the SEC reporting requirements involved in the decree").Although settlement negotiations and offers are inadmissible (i) to show the validity or invalidity of a claim when validity is in dispute, (ii) to show the amount of damages when the amount is in dispute, or (iii) to impeach by showing a prior inconsistent statement or specific contradiction, settlement evidence is admissible to show that a party had knowledge or notice of a fact.

United States v. Seals, 493 F.3d 600, pin? (7th Cir. 2005) (by discussing only whether considerations such as relevance and prejudice render the other bad acts evidence admissible or inadmissible and by ignoring the possibility of a propensity inference, the court implicitly...Federal Rule of Evidence 404(b) does not prohibit a criminal defendant from offering other crimes or wrongs of non-defendants circumstantially.