The prohibition against circumstantial character evidence -- the prohibition, codified in Federal Rule of Evidence 404, against the use of a person's character to show that person's conduct -- does not apply to non-parties.

United States v. Geiger, 263 F.3d 1034, 1038-1039 (9th Cir. 2001) (upholding trial court's admission of arresting officer's prior testimony at the federal suppression hearing because "[u]nder Rule 804(b)(1), prior testimony....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.

Small v. Olympic Fabricators, Inc., 588 F.2d 287, 291 (9th Cir. 1978) (court finds no plain error but assumes the doctrine applies in this civil action).On rare occasions the plain error rule may be applied in favor of a civil litigant.

United States v. Schreane, 331 F.3d 548, 563-565 (6th Cir. 2003) (upholding trial court's ruling which allowed Officer Topping's testimony [about Duckett's statement during the stop] as an excited utterance because "Officer....A statement falls within the hearsay exception provided by Federal Rule of Evidence 803(2) only if the statement is related to a startling event or condition.