Evidence of a person's other sexual misconduct is frequently admissible in sexual assault cases, child molestation cases, and in civil cases involving claims of sexual misconduct.

Fed. R. Evid. 609(a)(1) ("(a) General rule. For the purpose of attacking the character for truthfulness of a witness, (1) evidence that a witness other than an accused has been....If a conviction is offered to impeach a witness and the conviction is not for a crime that involves dishonesty or false statement, the conviction of the witness may be used to impeach the witness if the crime for which the witness was convicted is punishable by death or imprisonment for more than a year, if the crime the witness committed is probative of the truthfulness of the witness, and if the opponent fails to show that the risk of prejudice or other harm mentioned in Federal Rule of Evidence 403 outweighs the probative value of the conviction; but if the witness to be impeached is a criminal defendant, the prosecution bears the burden of showing that the probative value of the conviction outweighs the risk of prejudice to the defendant.

Cf. United States v. Curtin, 443 F.3d 1084, 1092-1093 (9th Cir. 2006) (reversing [in part] conviction for traveling with intent to engage in a sexual act with a minor and remanding for new trial because the trial court erred in admitting evidence of stories describing sexual activity with children...If another crime or wrong is offered under the second sentence of Federal Rule of Evidence 404(b) to show the identity of an actor, wrongdoer, or defendant (e.g., to show that a criminal defendant rather than someone else committed the crime for which defendant is on trial), the other crime or wrong and the act, wrong, or crime at issue at trial must have been committed in a distinctive as well as similar fashion.

Perez v. Irwin, 963 F.2d 499, 502 (2d Cir. 1992) ("The Supreme Court in Holland v. United States, 348 U.S. 121, 140, 75 S.Ct. 127, 137, 99 L.Ed. 150 (1954), reh'g denied, 348 U.S. 121, 75 S.Ct. 127, 99 L.Ed. 150 (1955), defined reasonable doubt as a doubt that would cause a person to hesitate to act in...Courts have approved jury instructions saying that a reasonable doubt is a doubt that would cause a reasonable person to hesitate to act before making an important or critical private decision.