State v. Southard

Oregon Supreme Court · 2009 · Evidence

347 Ore. 127 (2009)

Updated August 22, 2026

EvidenceOEC 702OEC 403scientific evidencechild sexual abuse diagnosisexpert testimonycredibilityunfair prejudice

Facts

After defendant moved in with his girlfriend and her two children, the boy later displayed sexualized behaviors and told his grandmother that defendant made him suck defendant's penis and made his younger sister do the same. The children were referred to the KIDS Center, which used standardized history-taking, videotaped interviewing, and medical examination procedures; the boy's exam showed no physical evidence of abuse, and the girl denied abuse. Based on the boy's statements, reported behaviors, and the center's assessment that his account was credible, a physician diagnosed the boy as having been sexually abused. Defendant moved in limine to exclude any diagnosis of sexual abuse as scientific evidence, but the trial court admitted it.

Issue

Whether, in the absence of physical evidence of abuse, a physician's diagnosis that a child was sexually abused is admissible scientific evidence. More specifically, whether that diagnosis, though scientifically valid, should be excluded because its probative value is substantially outweighed by the danger of unfair prejudice.

Rule

A diagnosis of child sexual abuse can possess sufficient indicia of scientific validity to satisfy OEC 702 even without physical evidence of abuse. However, where the expert's ultimate diagnosis does not tell the jury anything it could not determine on its own and is based primarily on credibility assessments the jury is equally competent to make, the diagnosis is inadmissible under OEC 403 because its minimal probative value is substantially outweighed by the danger that jurors will defer to the expert's scientific aura.

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One of 10 multiple-choice questions for this case. Pick an answer to see why.

In Portland, seven-year-old Eli Moreno told his aunt that his mother's boyfriend made him perform oral sex. A physician at Cascade Children's Clinic used standardized interviewing guidelines, reviewed Eli's caregiver history, found no physical injury, and then testified that Eli had been sexually abused.

If the defense objects only to the physician's ultimate diagnosis, how should the court rule?

Explanation. The majority held that such a diagnosis may satisfy scientific-validity requirements under OEC 702 even without physical evidence. But when the ultimate conclusion that abuse occurred depends primarily on deciding whether to believe the child's account, the jury is equally capable of making that determination. In that setting, the diagnosis has minimal probative value and creates substantial unfair prejudice because jurors may defer to the expert's scientific aura rather than make their own credibility judgment.