State v. Mendoza-Sanchez

Excluding expert testimony that relates to facts presented that would raise doubt to the central issue in the case is not harmless error.

Defendant appealed his conviction for unlawful sexual penetration and sexual abuse. Defendant assigned error to the trial court’s decision to exclude expert testimony about "memory source confusion." On appeal, Defendant argued that the identification of complainants’ abusers was central to the case, and testimony that their memories were altered over time to confuse the identities of their abusers with defendants would have explained the reasonable possibility that the “abuse was committed by other individuals” and the “psychological mechanisms” that create that confusion. In response, State argued that Defendant “failed to identify any non-speculative . . . specific admissible evidence to support a source confusion theory of defense.”

Under OEC 702, expert testimony is helpful if, among other things, the opinion's foundation "intelligibly relate[s] the testimony to the facts.” The Court held that the trial court erred when it excluded the expert testimony on memory source confusion because the defense presented evidence to support the theory that complainants were abused by the neighbors, not defendants who had similar features. Thus, expert testimony about memory confusion related to facts that would have raised doubt to the defendants’ identities as complainants’ abusers by aiding “the jury in understanding how a victim of sexual abuse could confuse the identity of her abuser.” This error was not harmless. Reversed and remanded, otherwise affirmed.