Post-Ruan CSA Prosecutions: Objective “Legitimate Medical Purpose/Usual Course” Criteria Remain Valid, and Masked Witness Testimony Is Not Plain Error Absent Prejudice

Case: United States v. Bernard Shelton (6th Cir. July 1, 2026) (Davis, J.)
Core holdings: (1) Evidence sufficed to prove a physician knowingly/intentionally prescribed controlled substances without authorization; (2) 21 C.F.R. § 1306.04(a) is consistent with the CSA, defeating (on plain-error review) nondelegation and major-questions attacks; (3) jury instructions may use objective “legitimate medical purpose/usual course” criteria as circumstantial evidence of subjective mens rea under Ruan; (4) requiring testifying witnesses to wear masks was not reversible plain error absent a showing of prejudice.

I. Introduction

Bernard W. Shelton, a Michigan internist and solo practitioner registered with the DEA, was convicted by a jury of twenty-one counts of unlawfully distributing controlled substances under the Controlled Substances Act (“CSA”), 21 U.S.C. § 841(a)(1). One count carried the death-results enhancement under 21 U.S.C. § 841(b)(1)(C) based on patient Dennis Hoey’s overdose death from oxycodone prescribed by Shelton.

The government’s proof portrayed a practice dominated by controlled-substance prescribing, frequent “pill mill” red flags (doctor shopping, requests by drug name, dangerous drug combinations, failed or missing drug screens, minimal or nonexistent exams, suspicious MAPS data, and falsified documentation), and continued prescribing despite indications of diversion and substance misuse.

On appeal, Shelton raised four clusters of issues:

  • Sufficiency: whether the evidence showed he knowingly/intentionally prescribed “without authorization.”
  • Regulatory authority: whether the Attorney General/DEA may define authorization via 21 C.F.R. § 1306.04(a), challenged under nondelegation and the major questions doctrine.
  • Jury instructions: whether the instructions impermissibly “objectified” authorization and diluted Ruan’s mens rea requirement.
  • Confrontation Clause: whether requiring witnesses to testify masked violated face-to-face confrontation.

II. Summary of the Opinion

The Sixth Circuit affirmed across the board. It held:

  • The record contained abundant circumstantial evidence supporting the jury’s finding that Shelton knew or intended his prescribing was unauthorized.
  • Shelton’s nondelegation and major-questions challenges to 21 C.F.R. § 1306.04(a) failed on plain-error review, particularly because Supreme Court precedent treats the regulation as effectively tracking the statute.
  • The jury instructions correctly captured Ruan v. United States by requiring proof that Shelton knew or intended the prescriptions were unauthorized, while allowing objective medical-practice criteria as circumstantial evidence of that subjective state of mind.
  • The mask requirement did not warrant reversal under plain-error review, mainly because Shelton failed to show prejudice—i.e., a reasonable probability of a different outcome.

III. Analysis

A. Precedents Cited (and How They Shaped the Decision)

1) Sufficiency of the evidence and proof of mens rea

  • United States v. Siefert: supplied the sufficiency standard—affirm if “any rational trier of fact” could find guilt beyond a reasonable doubt, viewing evidence in the government’s favor.
  • United States v. Jackson: reinforced appellate restraint—no reweighing evidence or credibility reassessments.
  • Burrage v. United States: provided the elements for the § 841(b)(1)(C) enhancement; Shelton conceded causation, so the appeal centered on “unauthorized” distribution and mens rea.
  • United States v. Getachew: crystallized the Sixth Circuit’s post-Ruan framework: unauthorized prescribing means lacking “legitimate medical purpose” and being outside the “usual course,” and the government must prove the doctor knew or intended the lack of authorization.
  • Ruan v. United States: the lodestar for mens rea; it permits objective medical-practice criteria to be used as circumstantial evidence of subjective knowledge/intent.
  • United States v. Bauer: emphasized that a jury may infer subjective knowledge from repeated, obvious departures from professional norms and “objective criteria,” and it supported the court’s use of “red flags” evidence.
  • United States v. Romano: supported using a defendant-doctor’s own statements (fear of “getting in trouble”) as circumstantial evidence of awareness of wrongdoing.
  • United States v. Stanton and United States v. Anderson: validated treating classic “pill mill” indicators (distance traveled, drug screens, addiction signs) as probative of illegitimacy and knowing misconduct.
  • United States v. Sherman: supplied a near-direct template for the panel’s inference: failure to examine, diagnose, heed red flags, or try conservative measures can support a finding of subjective knowledge and intent.
  • United States v. Washington: used by analogy for the proposition that falsified records can support an inference of knowledge/intent.

2) Nondelegation and the CSA’s regulatory structure

  • United States v. Burrell, United States v. Tellez, and United States v. Woodruff: framed and constrained the analysis via plain-error review; absent clear on-point authority establishing error, Shelton could not show an “obvious or clear” mistake.
  • Touby v. United States and Mistretta v. United States: supplied the governing nondelegation standard (the “intelligible principle” test).
  • Gonzales v. Oregon: pivotal—its characterization of 21 C.F.R. § 1306.04(a) as “merely to paraphrase the statutory language” undercut Shelton’s claim that the Attorney General “narrowed” or substantively redefined authorization.
  • United States v. Moore: anchored the proposition that registered physicians may be prosecuted when they act outside “the usual course of professional practice,” tying the CSA to professional-practice boundaries.
  • United States v. Wandahsega: invoked for vertical stare decisis—this panel would not depart from Supreme Court guidance about the regulation’s function.

3) Major questions doctrine

  • Allstates Refractory Contractors, LLC v. Su, West Virginia v. EPA, and Gundy v. United States: supplied the doctrine’s “extraordinary cases” framing and the “clear congressional authorization” requirement.
  • Learning Resources, Inc. v. Trump: used to characterize “transformative” agency assertions as the doctrine’s target; the court treated § 1306.04(a) as non-transformative because it tracks statutory language and longstanding CSA enforcement.
  • United States v. Kirk and United States v. Fletcher: supported the view that the CSA does not federalize medical standards by regulation; rather, legitimacy is proven through traditional evidentiary tools like expert testimony about generally accepted practice.

4) Jury instructions after Ruan

  • United States v. You and United States v. Betro: provided the review framework—legal accuracy de novo; reversal only if instructions as a whole were confusing, misleading, or prejudicial.
  • United States v. Campbell: reinforced that objective criteria may be used to prove knowledge of lack of authorization.
  • United States v. Iwas, United States v. Herrell, and United States v. Anderson: treated instructions as Ruan-compliant when they repeatedly focus the jury on the defendant’s knowledge that prescriptions were not legitimate/usual-course, even if objective criteria are referenced.

5) Confrontation Clause and masked testimony

  • Delaware v. Van Arsdall: reaffirmed the Confrontation Clause’s “main and essential purpose” as securing cross-examination.
  • Pitts v. Mississippi, Coy v. Iowa, and Maryland v. Craig: supplied the face-to-face baseline, the possibility of exceptions, and the requirement of case-specific necessity findings when deviating from face-to-face confrontation.
  • Crawford v. Washington: cited to highlight tension with open-ended balancing approaches, underscoring doctrinal sensitivity around confrontation.
  • United States v. Maynard, United States v. Jenkins, and United States v. Graham: persuasive authority from sister circuits supporting masking practices under COVID-era public-policy needs and recognizing alternative demeanor cues beyond full facial visibility.
  • United States v. Hills: used to deny “plainness” where there is no binding, on-point precedent.
  • United States v. Hamm, Molina-Martinez v. United States, and United States v. Smith: provided the prejudice framework for plain error; the court assumed arguable error but found no showing the outcome would have changed.

B. Legal Reasoning

1) “Unauthorized” prescribing: objective criteria as evidence of subjective knowledge

The opinion’s central move is to keep two ideas distinct but connected:

  • Authorization’s content: whether prescriptions were for a “legitimate medical purpose” in the “usual course of professional practice” (language drawn from 21 C.F.R. § 1306.04(a) and echoed throughout the CSA).
  • Authorization’s mens rea: whether Shelton knew or intended that his prescriptions were unauthorized, as required by Ruan v. United States.

The court treated the government’s evidence of repeated red flags (doctor shopping, requests by name, “holy trinity” combinations, ignored MAPS and drug screens, prescribing without exams, suspicious patient behavior, and alleged falsified notes) as classic circumstantial evidence that Shelton’s departures from medical norms were not accidental. Relying heavily on United States v. Getachew, United States v. Bauer, and United States v. Sherman, the panel concluded that a rational juror could infer subjective awareness from the “compounding” of objectively egregious indicators.

2) Rejecting the regulatory-structure attack (nondelegation and major questions) on plain-error review

Shelton’s broader strategy was to destabilize the “authorization” framework by attacking the Attorney General’s authority to define it through regulation. The court’s response proceeded in three steps:

  • Procedural constraint: because the argument was raised post-trial, review was for plain error, requiring an “obvious or clear” legal error.
  • Substantive incompatibility with precedent: Gonzales v. Oregon characterizes 21 C.F.R. § 1306.04(a) as “merely to paraphrase the statutory language,” making it difficult to label the regulation as an unconstitutional legislative expansion.
  • Textual/statutory reinforcement: the panel pointed to CSA provisions that themselves employ “legitimate medical purpose” and “usual course of professional practice” terminology (including 21 U.S.C. §§ 801(1), 802(21), 822(b), 829(e)(2)(A), 830(b)(3)(A)(ii)), concluding the regulation “hewed to” Congress’s own terms.

The major questions doctrine failed for related reasons: the court treated the regulation as non-transformative and consistent with long-recognized CSA authority to prosecute practitioners who operate outside professional practice (United States v. Moore), while leaving the proof of medical norms to “traditional means” like expert testimony (United States v. Kirk).

3) Jury instructions: Ruan’s mens rea preserved, objective criteria permitted

The panel upheld instructions that:

  • Defined authorization as “legitimate medical purpose” in the “usual course,”
  • Required proof beyond a reasonable doubt that Shelton issued each prescription “knowing or intending” it was unauthorized, and
  • Explained that objective illegitimacy (lack of legitimate purpose/usual course) is not, by itself, enough—but is permissible circumstantial evidence of knowledge.

This tracks the opinion’s broader theme: objective criteria may inform the inference of subjective mens rea without replacing it. The court aligned the instruction with Ruan v. United States and its own applications in United States v. Bauer, United States v. Campbell, United States v. Iwas, and United States v. Herrell.

4) Mask mandate: no reversible plain error without a concrete showing of prejudice

The court acknowledged the doctrinal pull of Maryland v. Craig and Pitts v. Mississippi, including the requirement of case-specific necessity findings when deviating from face-to-face confrontation. It also recognized the absence of Sixth Circuit/Supreme Court precedent squarely addressing face masks that partially cover a witness’s face.

The decisive point, however, was prejudice. Even assuming error, Shelton did not identify any specific witness or credibility determination likely affected by masking, nor explain how unmasked demeanor would have created a reasonable probability of acquittal. Because witnesses were in court, under oath, subject to cross-examination, and observable in other demeanor respects, Shelton failed to satisfy the plain-error standard’s substantial-rights prong.

C. Impact

1) CSA “pill mill” prosecutions after Ruan

Shelton reinforces a practical prosecution pathway in the Sixth Circuit: the government may build mens rea through an accumulation of objective “red flags” and deviations from standard care, while still arguing (and instructing) that the jury must find the practitioner knew or intended the lack of authorization. The decision further normalizes expert testimony on “usual course” standards as central evidence, consistent with United States v. Kirk.

2) Regulatory stability: § 1306.04(a) insulated (at least from plain-error attack)

The court’s reliance on Gonzales v. Oregon and statutory text signals that, in the Sixth Circuit, broad-based constitutional attacks on 21 C.F.R. § 1306.04(a) face steep odds—particularly when raised late. Defendants seeking to contest authorization will likely focus less on dismantling the regulation and more on disputing knowledge/intent and the credibility of expert “standard of care” proof.

3) Jury instruction drafting

Shelton gives district courts a blueprint: instructions may define authorization using “legitimate medical purpose/usual course” language and expressly tell jurors that objective deviations are not enough alone but can be used as circumstantial evidence of knowledge. This reduces the risk of reversal so long as the charge “refers continuously” to the defendant’s knowledge, echoing United States v. Anderson and United States v. Iwas.

4) Courtroom masking and confrontation

While not declaring masked testimony categorically constitutional, Shelton suggests two practical litigation consequences:

  • Preservation matters: objections should be made contemporaneously to trigger findings under Maryland v. Craig and Pitts v. Mississippi.
  • Prejudice must be articulated: on appeal—especially under plain error—a defendant must connect masking to specific credibility disputes that plausibly affect the verdict.

IV. Complex Concepts Simplified

  • “Except as authorized” (CSA): Even though doctors can prescribe controlled substances, that authority is limited. Prescriptions are “authorized” only if they are issued for real medical treatment and within professional practice norms.
  • 21 C.F.R. § 1306.04(a): The regulation states that a controlled-substance prescription must be for a legitimate medical purpose and issued in the usual course of professional practice. Shelton treats this as matching—rather than rewriting—the CSA.
  • Ruan mens rea: A doctor is not convicted just because a prescription was objectively improper; the government must prove the doctor knew or intended it was unauthorized. Objective “red flags” are allowed as evidence from which knowledge can be inferred.
  • Nondelegation doctrine: Congress cannot hand off pure lawmaking power without an “intelligible principle” guiding the agency. Shelton holds there is no clear (plain) error because the regulation tracks Congress’s own terms and Supreme Court precedent treats it as a paraphrase.
  • Major questions doctrine: In extraordinary cases, courts demand clear congressional authorization for sweeping agency power. Shelton views § 1306.04(a) as neither extraordinary nor transformative.
  • Plain-error review: If an issue wasn’t properly raised at trial, the appellant must show a clear legal error and that it likely changed the outcome. Shelton repeatedly turns on this “prejudice” requirement.
  • Confrontation Clause (face-to-face): Defendants generally have the right to face accusers, but exceptions exist for necessity and important public policy. Shelton does not decide the ultimate mask question categorically; it denies relief because the claimed error was not plainly established and, critically, not shown to be outcome-determinative.

V. Conclusion

United States v. Bernard Shelton consolidates the Sixth Circuit’s post-Ruan approach to practitioner prosecutions under the CSA: authorization is assessed using the familiar “legitimate medical purpose/usual course” framework, and objective departures from medical norms may serve as powerful circumstantial evidence that a defendant knew or intended he was acting without authorization. The decision also fortifies the perceived statutory pedigree of 21 C.F.R. § 1306.04(a), rejecting late-raised nondelegation and major-questions attacks on plain-error review. Finally, Shelton underscores that Confrontation Clause challenges to courtroom masking—especially when unpreserved—require a concrete, witness-specific showing of prejudice to justify reversal.