When does conceding expert testimony admissibility waive appellate review in Utah? State v. Castillo Explained

Background and facts

Salvador Castillo was convicted of four counts of aggravated sexual abuse of a child and one count of rape of a child after a jury trial in the Third District Court. The State called a Children’s Justice Center forensic interviewer as a blind expert witness to testify generally about delayed disclosure of child sexual abuse. Before trial, Castillo moved to exclude the expert under Utah Rule of Evidence 702, but during oral argument on the motion his counsel expressly stated he was “okay” with the expert testifying about the reasons children delay reporting abuse — his only concern was that the expert might quantify those behaviors using terms like “common” or “rare.” The trial court excluded quantification testimony but allowed the rest. When the expert nonetheless testified at trial that false allegations of child sexual abuse are “rare,” defense counsel requested a sidebar rather than a formal objection. The jury convicted on all counts.

Key legal issues

The Utah Supreme Court addressed four categories of alleged error: (1) admission of the expert’s testimony under Rule 702; (2) ineffective assistance of counsel for failing to formally object to the expert’s “rare” comment and for not objecting to use of the word “victim” at trial; (3) ineffective assistance for failing to object to the complaining witness’s testimony about self-harm; and (4) whether the trial court erred in denying a directed verdict because the complaining witness’s testimony was inherently improbable under State v. Robbins, 2009 UT 23.

Court’s analysis and holding

The court held that Castillo waived most of his Rule 702 reliability and sufficiency objections by affirmatively conceding their admissibility during the pretrial hearing. Citing State v. Johnson, 2017 UT 76, the court reiterated that waiver — including implied waiver through abandonment — bars appellate review. On ineffective assistance, the court applied the two-prong Strickland v. Washington standard and found Castillo failed to establish deficient performance on any claim. Counsel’s decision to address the expert’s “rare” comment through sidebar and cross-examination rather than a formal objection was a legitimate tactical choice to avoid highlighting unfavorable testimony. The court further held that generic references to “victims” — not directed at the complaining witness specifically — did not implicate the concerns identified in State v. Vallejo, 2019 UT 38. On the Robbins inherent improbability issue, the court confirmed that a defendant must specifically invoke Robbins, identify the testimony to be disregarded, and support the challenge with evidence and legal authority — a generic “insufficient evidence” argument does not preserve it.

Practice implications

This decision carries several important lessons for Utah appellate practitioners. First, any affirmative concession during a pretrial hearing that certain evidence is admissible will be treated as a waiver foreclosing appellate review — and a subsequent ineffective assistance claim will fail if counsel did not articulate why the concession was unreasonable under Strickland. Second, to preserve a Robbins inherent improbability challenge, counsel must specifically invoke Robbins, identify the precise testimony to be disregarded, and present supporting evidence and authority at the directed verdict stage — a general sufficiency challenge is categorically insufficient. Third, when use of the word “victim” is at issue, courts will examine whether the reference is directed at the specific complaining witness or is a generic reference to a class of persons, with only the former raising serious constitutional concerns.