Ensuring Reliability in CSAAS-Based Expert Testimony: Daubert Compliance under MRE 702

Introduction

The Michigan Supreme Court’s May 2, 2025 order in People of the State of Michigan v. Juan Jose Del Cid (SC No. 167877) denied leave to appeal a Court of Appeals decision that upheld the trial court’s refusal to exclude expert testimony on delayed disclosure of child sexual abuse. Although the majority concluded that the questions presented did not merit review, Justice Thomas concurred to highlight an unresolved tension between the Court’s 1995 decision in People v. Peterson—which permitted testimony on typical victim behaviors under the now-obsolete Davis/Frye test—and the current Daubert-driven admissibility standards of Michigan Rule of Evidence 702. This concurrence urges a definitive statement on the need for reliability testing of CSAAS-based expert testimony.

Summary of the Judgment

The Supreme Court denied leave to appeal, finding no compelling reason to revisit the expert-testimony issues in this particular case. A separate concurrence emphasized that although petitioners did not squarely present the scope and reliability questions, the Court ought to clarify whether expert testimony grounded in Child Sexual Abuse Accommodation Syndrome (CSAAS) must undergo a Daubert hearing under MRE 702’s reliability requirements before admission at trial.

Analysis

Precedents Cited

• People v. Kowalski, 492 Mich 106 (2012) – Established the two-part “threshold inquiry” under MRE 702: (1) helpfulness to the trier of fact (“beyond common knowledge”), and (2) reliability of the expert’s methods and application.
• MRE 702 – Requires expert testimony to be based on sufficient facts/data, reliable principles/methods, and a reliable application to the case facts.
• Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579 (1993) – Mandates the trial judge’s gatekeeping role to ensure both relevance and reliability of “scientific testimony.”
• Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999) – Extends Daubert gatekeeping to all “technical” or “other specialized” knowledge.
• People v. Peterson, 450 Mich 349 (1995) – Under Davis/Frye, permitted expert testimony on typical child-abuse victim behaviors (secrecy, delayed disclosure, etc.) to explain otherwise “inconsistent” victim conduct.
• People v. Beckley, 434 Mich 691 (1990) – Held that Davis/Frye does not apply to behavioral-science testimony.
• People v. Spaulding, 332 Mich App 638 (2020) & People v. Muniz, 343 Mich App 437 (2022) – Lower-court decisions admitting CSAAS-style testimony without a reliability analysis, citing Peterson.
• People v. Gilbert (DaimlerChrysler), 470 Mich 749 (2004) – Adopted Daubert and clarified MRE 702’s modern standard.

Legal Reasoning

Justice Thomas’s concurrence underscores that MRE 702 demands two independent showings before expert testimony is admitted: first, that the subject matter lies outside the jury’s common knowledge and will assist in understanding facts in issue; second, that the expert’s methods and application are demonstrably reliable. While Peterson predates Daubert and allowed CSAAS-style evidence under Davis/Frye, the current regime compels reliability testing. Drawing on Kowalski, the concurrence argues that testimony about child-abuse victim behavior—like false‐confession evidence—may clear the “helpfulness” bar but still requires a Daubert hearing to confirm the science or methodology underpinning that testimony.

Impact on Future Cases

If the Court adopts Justice Thomas’s view in a future case, trial courts would be required to conduct Daubert hearings before admitting expert testimony based on CSAAS or similar frameworks. This will:

• Ensure that only scientifically grounded, peer-reviewed, and statistically supported expert opinions reach the jury.
• Promote the development of a robust factual and methodological record regarding CSAAS in Michigan.
• Align Michigan with other jurisdictions scrutinizing the validity of behavioral-science testimony.
• Influence counsel on both sides to prepare rigorous reliability challenges or defenses.

Complex Concepts Simplified

Daubert Hearing

A pretrial “gatekeeper” proceeding in which the judge evaluates whether expert evidence is both relevant and scientifically reliable under factors such as testability, peer review, error rates, and general acceptance.

Child Sexual Abuse Accommodation Syndrome (CSAAS)

A descriptive model identifying five common victim reactions—secrecy, helplessness, entrapment/accommodation, delayed/conflicted disclosure, and retraction—originating in Summit, Child Abuse & Neglect (1983).

Threshold Inquiry vs. Reliability Analysis

Threshold Inquiry (MRE 702): Determines whether expert testimony will aid the jury in understanding evidence beyond ordinary experience.
Reliability Analysis (Daubert factors): Assesses whether the expert’s principles and methods are scientifically sound and properly applied.

Conclusion

The concurrence in People v. Del Cid signals a critical juncture for Michigan evidence law. Although leave was denied, the call to reconcile Peterson with modern Daubert requirements under MRE 702 has profound implications: expert testimony on child-abuse victim behavior must not be admitted as a matter of course but must first clear a reliability gate. A clear ruling on this issue would safeguard trial fairness, encourage rigorous scientific standards, and shape the admissibility landscape for behavioral-science experts in criminal proceedings statewide.