Expert testimony concerning a victim witness’s diagnosis of dissociative amnesia would assist the trier of fact, and the trial court’s exclusion of such testimony was not harmless error, according to the Supreme Court of Oregon.

It was a case of he said, she said. Neither side offered any forensic evidence, therefore, the outcome of the trial would turn on the credibility of the witnesses.

The victim of a kidnapping, physical, and attempted sexual assault gave variable and inconsistent accounts of the incidents, including in one account that her attacker spoke Spanish well, and in another, that he did not. The defendant, Gabriel Gherasim, a Romanian, sought to introduce expert testimony that the victim suffered from dissociative amnesia to bolster his defense theory that the victim confused his attempt to rescue with the original attack.

One characteristic of the condition is that memory gaps are filled in with later events, and the gaps are related to traumatic events. The trial court did not admit the testimony; to remove the portions which impermissibly commented on the victim’s credibility, a determination for the jury, would reduce the testimony to simply "people under stress have trouble remembering things"—something most people would consider common sense.

Assisting the Jury?

After being convicted at trial, Gherasim appealed. The appeals Court reversed. The state on appeal conceded that the testimony was not impermissible comment upon the victim’s credibility, but requested the Court to find that the testimony was confusing, commonly understood, or not helpful.

The Supreme Court upheld the decision of the appeals court. In so doing, the Court stated that since the outcome rested solely upon whose version of events the jury believed, and the condition affected the victim’s capacity to remember what had occurred on the night of the assault. The testimony would therefore have been helpful, and its exclusion was not harmless.