Whether another crime may be used "circumstantially" -- i.e., for a purpose other than witness impeachment -- and for an otherwise permissible non-propensity purpose even if the person who allegedly committed the other crime was acquitted of the other crime in a different trial.

Sims v. Great American Life Ins. Co., 469 F.3d 870, 881-882 (10th Cir. 2006) (in the course of a discussion of whether some Federal Rules of Evidence violate the Erie doctrine in certain kinds of civil cases, the court of appeals said, "Most pertinent to this case, Rule 401 protects against incursion...The technical definition of relevance in Federal Rule of Evidence 401 and in comparable State rules provides that evidence is "relevant" only if the evidence increases or decreases the probability of a fact that is "of consequence to the determination of the action."

Fed. R. Evid. 801(d)(1)(A) ("A statement is not hearsay if-- (1) Prior statement by witness. The declarant testifies at the trial or hearing and is subject to cross-examination concerning the statement, and the statement is (A) inconsistent with the declarant's testimony, and was given under oath subject to the penalty of perjury at a...A prior statement is exempt from the federal hearsay rule and is admissible to prove the truth of the matter asserted by the declarant with the prior statement if the prior statement was made under oath in another proceeding and if the prior statement is inconsistent with the declararant's testimony or with the admitted hearsay statement of the declarant.

Fed. R. Evid. 412(b)(2) ("(b) Exceptions. ... (2) In a civil case, evidence offered to prove the sexual behavior or sexual predisposition of any alleged victim is admissible if it is otherwise admissible under these rules and its probative value substantially outweighs the danger of harm to any victim and of unfair prejudice to any...In a civil proceeding for sexual misconduct, other sexual conduct or sexual disposition of alleged victim is admissible if the probative value of the other conduct or of the victim's sexual disposition substantially outweighs the danger of harm to the alleged victim and the risk of unfair prejudice to a party.