Can expert witnesses testify about general patterns of child sexual abuse disclosure? State v. Mendoza Explained

In State v. Mendoza, the Utah Court of Appeals examined the admissibility of expert testimony about child sexual abuse disclosure patterns and the requirements for supplementing the record on ineffective assistance of counsel claims.

Background and Facts

Luis Mendoza was convicted of multiple counts of rape, aggravated sexual abuse of a child, object rape, and forcible sodomy for abusing his stepdaughter Gabriela over several years. The abuse occurred at multiple residences from when Gabriela was in elementary school through high school. Mendoza testified that a testicular hernia from a work injury prevented him from getting erections and committing the alleged acts. The State called a blind expert witness from the Children’s Justice Center who testified generally about how children disclose abuse and factors affecting when children disclose.

Key Legal Issues

Mendoza raised two ineffective assistance of counsel claims: (1) that counsel failed to object to the expert’s testimony about child abuse disclosure patterns and the State’s closing argument references to that testimony, and (2) that counsel failed to adequately investigate Mendoza’s medical condition by obtaining medical records and expert testimony. Mendoza also filed a rule 23B motion seeking remand to develop facts supporting his inadequate investigation claim.

Court’s Analysis and Holding

The Court of Appeals affirmed, finding no ineffective assistance. Regarding the expert testimony, the court distinguished State v. Burnett, noting that here the expert testified only about general patterns of child disclosure without commenting on the specific victim’s credibility. The court emphasized that expert witnesses may testify about common symptoms or behaviors of sexual abuse victims without violating Rule 403, provided they do not speak to the truthfulness of a particular witness. Counsel’s decision not to object was reasonable given existing case law supporting such testimony’s admissibility.

The court denied the rule 23B motion because Mendoza failed to provide affidavits demonstrating what counsel actually did or failed to do regarding investigation. The submitted nurse practitioner’s affidavit addressed only Mendoza’s medical condition but provided no information about counsel’s investigative efforts, making the claim speculative.

Practice Implications

This decision confirms that expert testimony about general patterns of child sexual abuse disclosure remains admissible in Utah courts, distinguishing such testimony from impermissible credibility evidence. For practitioners filing rule 23B motions, the decision underscores that affidavits must specifically address counsel’s conduct—not merely speculate about what additional evidence might have existed. The court will presume effective assistance where the record does not demonstrate otherwise.