Polygraph Results Offered to Bolster Credibility Fail Rule 702 and Cannot Establish Strickland Prejudice

Commentary on Randall Bruce Morris v. The State of Wyoming (2025 WY 98)

Introduction

In 2025 WY 98, the Wyoming Supreme Court affirmed the denial of a motion for a new trial brought by Randall Bruce Morris under W.R.A.P. 21, alleging ineffective assistance of counsel (IAC). A Campbell County jury had convicted Mr. Morris of first- and second-degree sexual abuse of a minor based on acts occurring in May 2022 and on Saturday, August 27, 2022. Post-trial, while his direct appeal was pending, Mr. Morris argued that his trial counsel performed deficiently by failing to request a Daubert hearing to admit his polygraph results—results that, he contended, showed “no deception indicated” when he denied touching the victim on “a Sunday in August.”

The central issue on appeal was narrow but consequential: whether the omission of a Daubert motion created Strickland prejudice. The Court answered no, holding that the polygraph results would not have been admissible under W.R.E. 702 because (1) the proposed use—bolstering the defendant’s credibility—invaded the jury’s core function as the arbiter of credibility and thus failed Rule 702’s “helpfulness” requirement; and (2) the exam did not “fit” the case because it addressed a different date than the charged conduct. The decision both reaffirms Wyoming’s Daubert framework and clarifies strategic limits on polygraph use in criminal trials.

Summary of the Judgment

• The Court reviewed the IAC claim under Strickland’s two-prong test (deficiency and prejudice) and chose to resolve the case on the prejudice prong alone.
• To show prejudice from failure to file a Daubert motion, a defendant must establish that the evidence would have been admitted under W.R.E. 702 and that there is a reasonable probability it would have affected the verdict.
• Mr. Morris failed both the “helpfulness” and “fit” components of Daubert/Rule 702:
  • Helpfulness: The defense intended to use the polygraph to bolster the defendant’s credibility—an impermissible encroachment on the jury’s role (“the jury is the lie detector”).
  • Fit: The polygraph question asked whether Mr. Morris touched the child “on that Sunday in August.” The charged conduct occurred in May and on Saturday, August 27. The mismatch renders the result irrelevant to the issues tried.
• The reliability record was also inadequate: the polygraph examiner’s testimony did not meaningfully address error rates, peer review, or current scientific standards.
• The Court declined to presume prejudice, distinguishing King v. State and noting its limited vitality.
• Result: Affirmed. The Rule 21 motion was properly denied; no Strickland prejudice was shown.

Analysis

Precedents Cited and How They Shaped the Holding

• Strickland v. Washington, 466 U.S. 668 (1984): The Court applied Strickland’s two-part test. Importantly, it followed Wyoming’s consistent approach of resolving IAC claims on the prejudice prong when dispositive. The Court reiterated that prejudice requires a reasonable probability of a different outcome absent the alleged deficiency.
• Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), adopted in Wyoming by Bunting v. Jamieson, 984 P.2d 467 (Wyo. 1999): The Court applied Daubert’s two-part test—reliability and relevance/“fit”—through W.R.E. 702. It relied on Hardman v. State, 2020 WY 11, and Reichert v. Phipps, 2004 WY 7, for the nonexclusive reliability factors (testability, peer review, error rate/standards, general acceptance, expertise, independence from litigation, and non-judicial uses).
• Wyoming’s Rule 702 Jurisprudence: The Court emphasized “helpfulness” as a gatekeeping threshold, citing cases that prohibit expert vouching:
  • Nania v. State, 2025 WY 16: “The jury is the lie detector.”
  • Craft v. State, 2013 WY 41, and W.R.E. 704: Even opinions on ultimate issues cannot include judgments of credibility or guilt.
• Wyoming’s IAC framework: The Court cited an array of cases reaffirming de novo review of legal conclusions and the practice of deciding IAC claims on prejudice alone where suitable: Mellott (2019), Griggs (2016), Winters (2019), Leners (2021), Yazzie (2021), Jendresen (2021).
• King v. State, 810 P.2d 119 (Wyo. 1991), and its limitation: While King presumed prejudice for failure to investigate eyewitnesses, the Court highlighted later criticisms of King’s breadth in Pickering v. State, 2020 WY 66, and Winters, 2019 WY 76. The Court distinguished King and declined to presume prejudice here.

The Court’s Legal Reasoning

1) Strickland Prejudice as the Decisional Ground

The Court sidestepped the deficiency question entirely, choosing the more efficient route: even if counsel should have requested a Daubert hearing, Morris could not show prejudice unless he first demonstrated the polygraph evidence would have been admissible and material. This approach reflects Wyoming’s steady adherence to Strickland’s instruction that courts may dispose of IAC claims on prejudice alone where appropriate.

2) Rule 702 “Helpfulness” and the Ban on Credibility Vouching

The defense candidly acknowledged that the polygraph was intended to bolster Mr. Morris’s credibility. That purpose flunks Rule 702’s threshold requirement that expert testimony “help the trier of fact” in a way that does not usurp the jury’s exclusive role in determining credibility. Wyoming’s jurisprudence is clear: expert testimony that implicitly or explicitly tells the jury who is telling the truth is inadmissible. By invoking Nania (“the jury is the lie detector”) and Craft, the Court framed polygraph results offered for credibility as classic vouching and therefore categorically unhelpful under Rule 702.

3) Daubert Reliability: An Inadequate Record

Even setting aside the vouching problem, the reliability showing was thin. The examiner testified to training and practice, but he did not substantively address:

• The error rates of current polygraph techniques,
• The specifics of peer review or the scientific literature validating the methodology, or
• Contemporary standards governing test administration and scoring.

With no robust reliability foundation in the Rule 21 record, the defense could not establish that a Daubert motion would have succeeded.

4) Daubert “Fit”: The Date Mismatch Was Dispositive

Daubert’s relevance requirement demands a “valid scientific connection” to the facts in dispute. The polygraph asked whether Mr. Morris touched the victim “on that Sunday in August,” keyed to a Denver Broncos–Minnesota Vikings preseason game. But the charged conduct occurred in May and on Saturday, August 27. The examiner himself stressed the question’s specificity to avoid “bleed-over” from other dates, which undercut any argument that passing the test said anything probative about the charged acts. In short, the polygraph did not “fit” the case; its exculpatory value was illusory.

5) No Presumption of Prejudice

Mr. Morris asked the Court to presume prejudice, analogizing to King. The Court refused. Unlike in King, there were no unexamined eyewitnesses whose testimony would have likely supported an innocence narrative. Here, the polygraph was neither demonstrably admissible nor exculpatory as to the specific charged conduct. The decision underscores Wyoming’s careful circumscription of presumed prejudice to rare, structural-like failures—not routine strategic or evidentiary omissions.

Impact

The decision has several practical and doctrinal consequences for Wyoming criminal litigation:

• Polygraphs remain functionally inadmissible to prove credibility. Parties should not expect to use polygraph results to tell the jury who is truthful. This opinion reinforces a bright-line sensibility grounded in Rule 702 helpfulness and anti-vouching principles.
• Daubert’s “fit” requirement is stringent. Even if a technique is reliable, it must match the precise facts in dispute. A polygraph question tethered to the wrong date will not be relevant, and a “no deception indicated” result will have no exculpatory force.
• Building a Daubert record matters. If a party seeks admission of scientifically contested methods, it must present data on error rates, peer review, standards, and general acceptance. Unsupported assurances by a practitioner will not suffice.
• IAC prejudice requires admissibility plus materiality. When the alleged deficiency is the failure to file a motion, a defendant must show the motion would have been granted and that the evidence would likely have altered the verdict. Speculation is insufficient.
• King’s presumption of prejudice remains narrow. The Court again signaled that presumed prejudice is reserved for rare scenarios akin to actual or constructive denial of counsel, not for ordinary failures to pursue evidentiary avenues.
• Plea and negotiation implications. Although not addressed directly, the opinion tacitly signals that polygraph results may continue to have non-trial utility (e.g., investigative leads or negotiation leverage), but their courtroom admissibility is highly constrained.

Complex Concepts Simplified

• W.R.A.P. 21 Motion: In Wyoming, a post-trial mechanism to raise ineffective assistance claims while a direct appeal is pending. It allows an evidentiary hearing in the district court before appellate briefing proceeds.
• Strickland Prejudice: Even if a lawyer erred, a defendant must show a reasonable probability that, but for the error, the outcome would have been different. Courts may decide an IAC claim solely on this prong.
• Daubert Hearing: A pretrial proceeding where the judge assesses whether expert evidence is both reliable and relevant. Reliability relates to scientific soundness (testing, peer review, error rates, acceptance). Relevance/“fit” asks whether the testimony meaningfully assists the jury on the precise facts at issue.
• Rule 702 “Helpfulness” and Vouching: Expert testimony must help the jury understand evidence or decide a fact without telling the jury whom to believe. Any expert statement that effectively declares a witness truthful is inadmissible vouching.
• “No Deception Indicated” (NDI): A polygraph conclusion suggesting the examinee’s physiological responses did not indicate deception in response to a particular question. Even an NDI result may be inadmissible if it fails Rule 702 or Daubert requirements.
• “Fit” in Practice: If the charged conduct is alleged to have occurred on May 10 and August 27, a polygraph question framed about “Sunday in August” does not fit and therefore does not assist the jury in deciding the relevant facts.

Practical Guidance for Litigants

• For defense counsel:
  • Do not rely on polygraphs to prove credibility at trial. Wyoming law disfavors such use and treats it as vouching.
  • If considering scientific evidence, build a robust Daubert record: current literature, error rates, accepted standards, and precise linkage to the disputed facts.
  • Ensure any proposed expert testimony directly addresses the acts, timeframes, and elements charged. Overly narrow or mismatched framing will fail the “fit” requirement.
  • When raising IAC via Rule 21, be prepared to show not only counsel’s omission but also that the omitted motion would have been granted and outcome-altering.
• For prosecutors:
  • Challenge polygraph evidence under Rule 702’s helpfulness and Daubert’s fit. Emphasize the anti-vouching doctrine.
  • Where polygraphs are discussed at all, focus the court on reliability lacunae and the risks of confusing or misleading the jury.
• For trial judges:
  • This opinion supports exclusion under Rule 702 where polygraph evidence is offered to bolster credibility or lacks fit, without needing to reach Rule 403.
  • Explicitly analyze both “helpfulness” and “fit” in Daubert rulings to create a clear appellate record.

Conclusion

Morris crystallizes two interlocking principles of Wyoming evidence and ineffective-assistance jurisprudence. First, polygraph evidence proffered to bolster a witness’s credibility fails W.R.E. 702’s helpfulness requirement and intrudes on the jury’s exclusive province as the trier of credibility; it is inadmissible regardless of any claimed exculpatory sheen. Second, to establish Strickland prejudice from an omitted Daubert motion, a defendant must demonstrate that the evidence would have cleared Rule 702’s reliability and “fit” hurdles and that its admission likely would have changed the verdict. The defense satisfied neither requirement here: the reliability showing was incomplete, and—most decisively—the polygraph question did not match the charged conduct.

By declining to presume prejudice and anchoring its analysis in Daubert’s gatekeeping framework, the Court reinforces a disciplined approach to expert evidence and to post-conviction claims premised on omitted motions. The takeaway is clear: absent a rigorous scientific foundation and a precise linkage to the disputed facts, polygraph results remain outside the courtroom—and cannot resuscitate an ineffective-assistance claim.