In the Interest of S.H.-S., 2026 Colo. App. LEXIS 1757 (Colo. Ct. App. 2026)

The Colorado Court of Appeals reversed and remanded an adjudication of sexual assault, finding that the trial court erred in permitting expert testimony suggesting that a witness was telling the truth and thus improperly bolstering the credibility of the witness.

The court stated in relevant part:

“In Colorado, neither lay nor expert witnesses may give opinion testimony that another witness was telling the truth on a specific occasion.” People v. Wittrein, 221 P.3d 1076, 1081 (Colo. 2009); see also People v. Baker, 2021 CO 29, ¶ 2, 485 P.3d 1100, 1102 (such testimony invades the jury’s credibility determinations). Improper truthfulness testimony is especially problematic in child sex assault cases, where the outcome often turns on whether the jury believes the child‘s testimony. Venalonzo v. People, 2017 CO 9, ¶¶ 32-33, 388 P.3d 868, 877-78 (therefore, both direct and indirect implications of a child‘s truthfulness are prohibited).

. . . .

Indeed, this testimony neither provided necessary context for Y.M.’s interview nor served any other purpose than to bolster Y.M.’s credibility. See Venalonzo, ¶ 36, 388 P.3d at 878 (testimony comparing child victims’ behavior to that of other child sex assault victims was improper bolstering); see also Snook, 745 P.2d at 649 (testimony that children do not fabricate stories of sexual abuse without it having happened to them was improper because “the jury’s only conceivable use of such testimony would be as support for the complainant’s truthful character”). As in most cases involving delayed reporting, Y.M.’s credibility was “the focal issue in the case.” Venalonzo, ¶ 33, 388 P.3d at 878 (quoting Snook, 745 P.2d at 649) (explaining this is when improper bolstering testimony is most problematic). We therefore conclude that the trial court abused its discretion by admitting it.