The Ninth released seven published decisions today. There was one habeas opinion, but the rest were civil. The habeas decision is worth noting because it is a grant and one of the civil cases is worth summarizing because it deals with experts under Fed. R. Evid. 702.
First, in Bieganski v. Shinn, --- F.4th ---, No. 23-1982 (9th Cir. 2025), the Court reversed the district court’s denial of Bradley Bieganski’s habeas petition challenging his Arizona jury conviction for child molestation and remanded with instructions to issue a writ of habeas corpus under 28 U.S.C. § 2254.
The Court held that Arizona’s statutory scheme unconstitutionally shifted the burden of disproving an essential element of the crime of child molestation to the defendant, contrary to the Due Process Clause of the Fourteenth Amendment. It is a long opinion. Here is some of the key language.
The question in this habeas case is whether Arizona’s statutory scheme unconstitutionally shifted the burden of disproving an essential element of the crime of child molestation to the defendant, contrary to the Due Process Clause of the Fourteenth Amendment as established in the Supreme Court’s decisions in, inter alia, Patterson v. New York, 432 U.S. 197 (1977); Mullaney v. Wilbur, 421 U.S. 684 (1975); and In re Winship, 397 U.S. 358 (1970). The district court concluded that the scheme did not violate the Due Process Clause. We reverse.The sole issue on appeal is whether Arizona’s former child molestation scheme—in which any knowing or intentional touching of a child was considered child molestation unless the defendant proved by a preponderance of the evidence that he lacked any sexual motivation—shifts the burden of proving an essential element of the offense of child molestation to the defendant in violation of the Due Process Clause of the Fourteenth Amendment.“[T]here are obviously constitutional limits beyond which the States may not go . . . .” Patterson, 432 U.S. at 210. But the constraints are few. The two principal constraints on state criminal laws are the Equal Protection and Due Process Clauses of the Fourteenth Amendment, which secure equality and fairness to “any person” subject to the state’s jurisdiction. U.S. Const. amend. XIV, § 1. Only the Due Process Clause is at issue here. That Clause provides that “no State shall . . . deprive any person of life, liberty, or property, without due process of law.” Id. The phrase “due process of law” is a capacious phrase including “the best ideas of all systems and of every age . . . to draw its inspiration from every fountain of justice.” Hurtado v. California, 110 U.S. 516, 531 (1884).The principle of due process at issue here is that “[g]uilt in a criminal case must be proved beyond a reasonable doubt,” Brinegar v. United States, 338 U.S. 160, 174 (1949), as to “every fact necessary to constitute the crime charged,” Davis v. United States, 160 U.S. 469, 493 (1895). That standard preserves “the presumption of innocence.” Winship, 397 U.S. at 363. The states, as we have noted, have broad leeway in determining what facts are “necessary to constitute the crime charged.” Id. The Court has warned that “we should not lightly construe the Constitution so as to intrude upon the administration of justice by the individual States,” as it is their business “to regulate procedures under which its laws are carried out, including the burden of producing evidence and the burden of persuasion.” Patterson, 432 U.S. at 201 (quoting Speiser v. Randall, 357 U.S. 513, 523 (1958)).Nevertheless, the Court has also been clear that even if “the Due Process Clause d[oes] not invalidate every instance of burdening the defendant with proving an exculpatory fact,” Patterson, 432 U.S. at 203 n.9, there is “some limit upon state authority to reallocate the traditional burden of proof,” Jones v. United States, 526 U.S. 227, 241 (1999) (citations omitted).A state is not required to prove “the nonexistence of all affirmative defenses[.]” Patterson, 432 U.S. at 210. Rather, “[t]he State is foreclosed from shifting the burden of proof to the defendant only ‘when an affirmative defense does negate an element of the crime.’” Smith, 568 U.S. at 110 (quoting Martin v. Ohio, 480 U.S. 228, 237 (1987) (Powell, J., dissenting)). A state cannot exercise “unlimited choice over characterizing a stated fact as an element,” because that “would leave the State substantially free to manipulate its way out of Winship.” Jones, 526 U.S. at 240–41.These are necessarily general prescriptions. In Morrison, the Court acknowledged that “[t]he decisive considerations are too variable, too much distinctions of degree, too dependent in last analysis upon a common sense estimate of fairness . . . to be crowded into a formula.” 291 U.S. at 91. Nevertheless, just this year the Court reminded us that “[g]eneral legal principles can constitute clearly established federal law for purposes of AEDPA” even if those principles lack “precise contours.” Andrew, 145 S. Ct. at 82 (quoting Lockyer, 538 U.S. at 72). We must therefore determine whether the Arizona Supreme Court unreasonably applied these general principles.We have profound concerns with the substance of the Arizona scheme, and with the Arizona Supreme Court’s analysis in Holle II. Those concerns persuade us that Arizona has shifted the burden of proving the only fact that really matters in child molestation cases—whether the defendant touched the child’s private parts with some kind of sexual motive. That fact is the only evidence that is morally inculpatory, what the Supreme Court referred to in the burden-shifting cases as the proof of “sinister significance.”Without the affirmative defense, child molestation in Arizona would be a strict liability crime: touch the child, you are a child molester. That is a dramatic, but not a hyperbolic, conclusion. And it was in its discussion of the affirmative defense that the Arizona Supreme Court sowed the undoing of its own analysis. The court acknowledged that “the criminal code should clearly differentiate between unlawful conduct and innocent, acceptable behavior.” Holle II, 379 P.3d at 206. The problem is that § 13-1410 contemplates no “innocent, acceptable behavior.” The statute is so broad that every knowing or intentional touching of a child’s genitals is “unlawful conduct.”First, citizens are not left to “the mercy of noblesse oblige.” United States v. Stevens, 559 U.S. 460, 480 (2010). The Supreme Court has warned us that courts should not “construe a criminal statute on the assumption that the Government will ‘use it responsibly.’” McDonnell v. United States, 579 U.S. 550, 576 (2016) (quoting Stevens, 559 U.S. at 480). And, most recently, in Trump v. United States, the Court repeated that courts should not “decline to decide significant constitutional questions based on the Government’s promises of good faith” in prosecutorial decisions. 603 U.S. 593, 637 (2024). The Arizona Supreme Court cannot avoid the implications of its analysis by assuring us that Arizona prosecutors will act responsibly.Arizona’s child molestation scheme is not just broad, it is pernicious. It criminalizes every knowing or intentional touching of a child’s private parts, no matter the reason. Everyone who knowingly changes a diaper could be convicted of child molestation, even when the state’s proof of that fact is not proof of any evil interest, but only of “traditionally lawful conduct.”Arizona has foisted the burden of proving the sexual motivation of the defendant on the defendant himself. This the state cannot do consistent with the Due Process Clause. “[E]very fact necessary to constitute the crime” charged must be proven by the state “beyond a reasonable doubt.” Winship, 397 U.S. at 364. The Supreme Court cases clearly establish that Arizona cannot shift the burden of proof to the defendant. See Smith, 568 U.S. at 110; Mullaney, 421 U.S. at 698; Morrison, 291 U.S. at 88, 90. Although the prohibition on burden-shifting is a general principle, “[g]eneral legal principles can constitute clearly established federal law for purposes of AEDPA . . . .” Andrew, 145 S. Ct. at 82. That said, we think there are several Supreme Court cases that amply demonstrate that Arizona has crossed the line in this instance.These cases clearly establish that the state is responsible for proving beyond a reasonable doubt the critical facts that establish the crime. Although § 13-1410 defines child molestation as “any touching” of a child’s genitals, the statute only requires the state to prove that the defendant “intentionally and knowingly” touched the child. In Arizona the fact of touching is essential to proving the crime, but everyone implicitly understands that it is not the sine qua non of child molestation and, absent some indication that the defendant touched the child with sexual interest, the touching will not be prosecuted.The core of child molestation in Arizona is that the defendant did so with sexual interest. That has historically been true in Arizona, see Part I.A., supra, and “Arizona stands alone among all United States jurisdictions in allocating the burden of proof this way,” May, 245 F. Supp. 3d at 1149. Without the element of sexual interest, the Arizona Supreme Court told us, we only have a “technical[]” violation of the statute that would be “improper[]” to prosecute. See Holle II, 379 P.3d at 206. What distinguishes a technical from a non-technical violation is, precisely, whether the defendant can successfully assert the affirmative defense of lack of sexual motivation. But the state is not required to prove the defendant’s sexual interest. Holle II makes clear that the fact is effectively presumed. This is a straightforward violation of clearly established due process principles, as determined by the U.S. Supreme Court. “Such shifting of the burden of persuasion with respect to a fact which the State deems so important that it must be either proved or presumed is impermissible under the Due Process Clause.” Patterson, 432 U.S. at 215.In the end, once we pierce the form of the state’s scheme, we have little difficulty concluding that Arizona has shifted the burden of proof from the state to the defendant to prove a core element of child molestation—that the defendant touched the child’s private parts with some kind of sexual interest. Arizona has done so in violation of the Due Process Clause of the Fourteenth Amendment, as clearly established in decisions of the United States Supreme Court. 28 U.S.C. § 2254(d)(1). In Bieganski’s case, the Arizona Court of Appeals was bound by Holle II. For the reasons we have explained, Holle II identified the correct legal principles in the Supreme Court’s cases, but its application of those principles to § 13-1410 was an objectively unreasonable one. See Williams, 529 U.S. at 413.
Next, in Engilis v. Monsanto Company, --- F.4th ---, No. 23-4201 (9th Cir. 2025), the Court affirmed the district court’s summary judgment in favor of Monsanto Company. It held that the district court did not abuse its discretion in excluding the opinion of an expert witness. Here is some of the relevant language.
Here, the district court concluded the expert’s differential etiology was unreliable pursuant to Federal Rule of Evidence 702 because the expert failed to reliably rule out obesity as a potential cause of Peter Engilis’s cancer. We affirm.The parties agree that the admissibility of expert testimony is controlled by Federal Rule of Evidence 702. See Elosu v. Middlefork Ranch Inc., 26 F.4th 1017, 1023 (9th Cir. 2022). That Rule provides that, “before admitting expert testimony, the district court must perform a gatekeeping role to ensure that the [proffered] testimony is both relevant and reliable.”In 2000, Rule 702 was amended for the first time to codify the holdings of the Daubert trilogy, and to resolve conflicts that had arisen within the courts about the meaning of that trilogy. Fed. R. Evid. 702 advisory committee’s note to 2000 amendment; Fern M. Smith, Report of the Advisory Committee on Evidence Rules 6–7 (1999) [hereinafter May 1, 1999 Report], https://perma.cc/LH3V-5GBB. The amendment “clearly envision[ed] a more rigorous and structured approach” to Rule 702 than some courts were then employing. May 1, 1999 Report at 7. It “affirm[ed] the trial court’s role as gatekeeper and provide[d] some general standards that the trial court must use to assess the reliability and helpfulness of proffered expert testimony.” Fed. R. Evid. 702 advisory committee’s note to 2000 amendment.The Rule was [] amended again in December 2023 to expressly require a proponent of expert testimony to “demonstrate[] to the court that it is more likely than not that” the four admissibility requirements are satisfied. Fed. R. Evid. 702 (2023). The amendment also modified subsection (d), which now requires that “the expert’s opinion reflects a reliable application of the principles and methods to the facts of the case.” Id.This amendment sought to “clarify and emphasize” that proffered expert testimony must meet the admissibility requirements of Rule 702 by a preponderance of the evidence. Fed. R. Evid. 702 advisory committee’s note to 2023 amendment. Before the amendment, “many courts” had erroneously held “that the critical questions of the sufficiency of an expert’s basis, and the application of the expert’s methodology, are questions of weight and not admissibility.” Id. Properly applied, Rule 702 requires that challenges to an expert’s opinion go to the weight of the evidence only if a court first finds it more likely than not that an expert has a sufficient basis to support an opinion. Id. The amendment also aimed “to emphasize that each expert opinion must stay within the bounds of what can be concluded from a reliable application of the expert’s basis and methodology.” Id. “Judicial gatekeeping is essential” to ensure that an expert’s conclusions do not “go beyond what the expert’s basis and methodology may reliably support.” Id. As the Advisory Committee’s note explains, the amendment did not “impose[] any new, specific procedures,” and was “simply intended to clarify” existing law. Id.[I]nsofar as the parties argue about the degree to which the amendments establish, or refute, that Rule 702 is a “liberal” standard that favors admission as “the rule, not the exception,” we confirm that a proponent of expert testimony must always establish the admissibility criteria of Rule 702 by a preponderance of the evidence and that there is no presumption in favor of admission.Several of our cases have stated that “Rule 702 should be applied with a ‘liberal thrust’ favoring admission.” Messick, 747 F.3d at 1196 (quoting Daubert, 509 U.S. at 588); Wendell v. GlaxoSmithKline LLC, 858 F.3d 1227, 1232 (9th Cir. 2017). Rule 702 liberalized the admission of expert testimony as compared to the Frye test, but it did not establish a categorical preference for admitting expert testimony.Our case law should not be understood to suggest a presumption of admission. There is no such presumption, as a proponent of expert testimony must always establish the admissibility requirements of Rule 702 by a preponderance of the evidence. See Fed. R. Evid. 702 (2023).We have also stated that, where experts’ opinions “are not the ‘junk science’ Rule 702 was meant to exclude,” Wendell, 858 F.3d at 1237 (citation omitted), “the interests of justice favor leaving difficult issues in the hands of the jury and relying on the safeguards of the adversary system . . . to ‘attack[] shaky but admissible evidence,’” id. (quoting Daubert, 509 U.S. at 596). To be sure, Rule 702 is concerned with “the soundness of [the expert’s] methodology,” rather than “the correctness of the expert’s conclusions.” Primiano, 598 F.3d at 564 (citation omitted). But “shaky” expert testimony, like any expert testimony, must still be “admissible,” and this requires a determination by the trial court that it satisfies the threshold requirements established by Rule 702.Only “[i]f the proposed testimony meets the thresholds of relevance and reliability” is its proponent “entitled to have the jury decide upon its credibility.” Elosu, 26 F.4th at 1024 (citation modified). The district court “cannot abdicate its role as gatekeeper,” nor “delegat[e] that role to the jury.”Consistent with the 2023 amendment, our precedent establishes that Rule 702 requires a proponent of expert testimony to demonstrate each of the requirements of Rule 702 by a preponderance of the evidence.The district court’s “responsibility to screen expert testimony,” Elosu, 26 F.4th at 1020, encompasses the requirement that expert testimony be “based on sufficient facts or data,” Fed. R. Evid. 702(b). This element “requires foundation.” Elosu, 26 F.4th at 1025. The “key inquiry” is “whether an expert had sufficient factual grounds on which to draw conclusions.”
