## Facts

- Amos John Chauvin, age 34, was accused of sexual misconduct involving two minors, including 15-year-old A.C., during a visit to a friend’s home on Father’s Day in 1999.
- A.C. testified Chauvin twice digitally penetrated her in the living room while others were outside, later French-kissed her when alone, and previously touched her breasts through clothing in a hallway.
- The second minor, A.L., testified Chauvin kissed her with his tongue later that day when he asked for a goodbye hug and kiss.
- After the incidents, the minors disclosed the conduct to others, and the matter was reported to police.
- The State charged Chauvin with multiple counts of indecent behavior with juveniles; a jury convicted him of two counts.
- Over defense objection, the State presented a licensed clinical social worker as an expert who treated A.C., diagnosed her with PTSD, and testified A.C.’s symptoms were consistent with sexual abuse; the State used this testimony as substantive support that abuse occurred.
- The court of appeal reversed and ordered a new trial, concluding the trial court failed to properly evaluate the reliability of the PTSD-based theory under Daubert and Louisiana’s Foret framework.

## Issues

1. Whether expert testimony diagnosing PTSD and stating a complainant’s symptoms are consistent with sexual abuse is admissible under Daubert/Foret.
2. Whether such PTSD-based testimony may be used as substantive evidence that sexual abuse occurred or to bolster the complainant’s credibility.
3. Whether admitting the challenged testimony required reversal of the convictions and a new trial.

## Decision

- The Louisiana Supreme Court reversed the court of appeal and reinstated the convictions.
- The court held PTSD-related expert testimony is not categorically inadmissible and may be admitted if shown reliable and relevant under Daubert/Foret.
- The court limited the permissible scope of the testimony: an expert may not opine that sexual abuse in fact occurred in the case or that the complainant is truthful.
- The court concluded the appellate reversal was unwarranted under the clarified standards and the trial record.

## Legal Principles

- Trial courts must serve a gatekeeping role to ensure expert testimony is relevant and reliable under Daubert as adopted in Louisiana by State v. Foret.
- PTSD is a recognized diagnosis, but using PTSD as a diagnostic marker to prove sexual abuse occurred requires careful reliability scrutiny and may not be presented as a scientific determination of abuse.
- Expert testimony may assist the jury by describing PTSD, its symptoms, and whether a complainant’s presentation is consistent with PTSD or with patterns observed among sexual-abuse complainants.
- Experts may not directly or indirectly vouch for a witness’s credibility or give an opinion that the defendant committed the abuse; credibility and guilt remain for the jury.

## Conclusion

The court permitted limited PTSD expert testimony to explain a complainant’s symptoms and behavior if reliable under Daubert/Foret, but prohibited experts from using PTSD testimony to prove the abuse occurred or to certify the complainant’s truthfulness, and it reinstated Chauvin’s convictions.


State v. Chauvin, 846 So. 2d 697 (La. 2003)