United States v. Clark & Mesner: Seventh Circuit Demands a Live Predicate for § 371 Conspiracy and Clarifies Use-of-Document Liability under § 1001(a)(3)

Introduction

The Seventh Circuit’s opinion in United States v. Shawn Mesner (consolidated with United States v. Derrick Clark) arises from the catastrophic 2017 explosion at Didion Milling’s grain mill in Cambria, Wisconsin. Five workers died, triggering a multi-agency investigation spearheaded by OSHA and, ultimately, a criminal prosecution. Two former senior employees—Vice-President of Operations Derrick Clark and Food-Safety Superintendent Shawn Mesner—were tried on an assortment of fraud, obstruction, and false-statement charges tied to doctored environmental and sanitation records. A jury convicted Clark on four counts and Mesner on two.

On appeal, the defendants launched multifaceted attacks: evidentiary objections to the admission of a co-conspirator’s plea statement, challenges to jury instructions, insufficiency-of-evidence arguments, and a vagueness claim aimed at an OSHA housekeeping regulation. In a lengthy and meticulous opinion authored by Judge St. Eve, the Seventh Circuit:

Affirmed all of Clark’s convictions,
Affirmed Mesner’s conviction for conspiracy to commit mail and wire fraud (Count 1), but
Vacated Mesner’s conviction for conspiracy to commit federal offenses under 18 U.S.C. § 371 (Count 4) because the government withdrew the only predicate act that applied to him yet still argued the conspiracy to the jury.

Summary of the Judgment

Admission of Plea Statement – The panel held that a factual statement incorporated into a plea agreement is admissible under Rule 801(d)(1)(A) as substantive evidence when the declarant adopted it under oath, rejecting Clark’s foundation, inconsistency, and Williamson-based objections.
Sufficiency of Evidence (Clark) – The court found ample evidence that Clark knowingly caused false WDNR compliance documents (Count 5) and aided and abetted the use of falsified baghouse logs submitted to WDNR (Count 6).
Jury-Instruction Challenges – Although the § 371 instruction lacked ideal clarity, any error was waived or at most harmless because the instructions, coupled with a special verdict form, required unanimous agreement on at least one specified federal offense.
Vagueness Attack – The panel declined to reach the constitutionality of OSHA’s grain-dust housekeeping rule because Clark was convicted of false-statement crimes, not of violating the housekeeping rule itself.
Vacatur for Mesner (Count 4) – The court reversed Mesner’s § 371 conviction because the sole predicate (falsification of sanitation logs under § 1001) had been dismissed at trial and never instructed, leaving no live offense on which the jury could lawfully convict.
Mail/Wire-Fraud Conspiracy (Mesner) – The court affirmed, holding that misleading sanitation records were material to buyers and that money remained the object of the scheme, satisfying Ciminelli and Kousisis.

Analysis

Precedents Cited and Their Influence

Ocasio v. United States – Clarified that § 371 conspiracy requires an agreement to commit the same underlying offense; used to frame jury-instruction analysis.
Ciminelli v. United States (2023) – Eliminated “right-to-control” property theory; defendants invoked it to attack the fraud count, but the panel distinguished the present case because money was the object.
Williamson v. United States – Offered the “narrow-statement” rule for 804(b)(3); Clark tried to import it into Rule 801(d)(1)(A) but the panel declined.
Rosemond v. United States – Applicability of aider-and-abettor liability: jury could convict Clark without proof that he committed every element so long as he furthered the principal’s offense.
Shorter, Christophel, Hughes – Guided the court’s plain-error review and unanimity-instruction discussion.
Salinas, Griggs – Confirmed that conspiring to commit any one of several enumerated crimes suffices as long as the jury is unanimous on at least one.

Legal Reasoning in Depth

1. Plea-Statement Admissibility under Rule 801(d)(1)(A)

The court held that when a cooperating witness swears to and adopts a factual résumé during a Rule 11 colloquy, that document becomes his statement, independent of government authorship. Thus, it is non-hearsay if introduced against him under Rule 801(d)(1)(A). Key points:

The judge who presided over the plea colloquy personally knew the witness adopted the whole statement; no transcript review was essential.
Rule 701 objections collapsed because the declarant had first-hand knowledge of conversations with Clark, satisfying the “rationally based on perception” requirement.
Any inconsistencies were fodder for cross-examination, not exclusion.

2. Aiding & Abetting Liability for “Use” of a False Document (§ 1001(a)(3) & § 2)

The panel set out a concise two-step analysis:

Principal Liability – Submission of doctored baghouse logs to WDNR satisfied “use” because the act implied their accuracy, aligning with Sixth Circuit precedent (Steele). “Representation of accuracy” does not require an express statement.
Clark’s Participation – Agreeing to strip highlight-coding that would have alerted inspectors was an affirmative act. Coupled with his knowledge of falsified readings, the jury could infer the requisite intent to facilitate Winch’s wrongdoing.

3. Boundaries of a § 371 Conspiracy

The decision’s most distinctive holding is that a § 371 conspiracy conviction cannot survive where:

The government abandons the only predicate offense applicable to the defendant, and
The jury is never instructed on that abandoned predicate.

Because Count 7 (§ 1001 based on sanitation logs) was dismissed before deliberations, and no evidence tied Mesner to other § 371 predicates (baghouse logs or OSHA deposition), the court ordered an acquittal on Count 4. This cements a clear rule in the Seventh Circuit: an appellate court will vacate a § 371 conviction that lacks a viable predicate actually presented to the jury.

4. Jury-Instruction Scrutiny and Waiver

The panel treated the challenged instruction in three slices:

Object of Conspiracy – Although the charge referenced a broad “overarching objective,” the instructions also enumerated each specific federal offense and supplied a special verdict form. Taken together, they satisfied Clay and Treadwell.
Different Predicate per Conspirator – Even if theoretically erroneous, the language was invited by Clark himself, amounting to waiver.
Unanimity – Global unanimity language and the special verdict form cured any possible ambiguity. The court reiterated that plain-error relief is rare where the verdict form confirms unanimity.

5. Fraud-Materiality Post-Ciminelli & Kousisis

For Count 1 the panel accepted both prevailing materiality formulations (“natural tendency” and “essence of the bargain”) because the record satisfied either. Multiple corporate buyers testified they would suspend or terminate purchases if they knew of falsified sanitation records, proving the representations’ capacity to influence economic decisions. Money—millions in corn-ingredient sales—was the unquestioned object, situating the case squarely within traditional property-fraud doctrine.

Impact of the Judgment

The opinion carries several forward-looking consequences:

Predicate-offense vigilance in § 371 cases – Prosecutors must ensure that every defendant is tied to at least one live, instructed predicate. Defense counsel can now cite Mesner to demand acquittal when the only applicable predicate evaporates.
Rule 801(d)(1)(A) expanded clarity – The decision endorses admitting plea agreements’ factual statements as substantive evidence, so long as adopted under oath. Expect more strategic drafting by prosecutors and heightened defense cross-examination on adoption.
Aiding-and-abetting “use” theory validated – Environmental and regulatory-compliance prosecutions will likely replicate the Seventh Circuit’s low bar for “use” of a document in § 1001(a)(3) cases.
Unanimity instruction approach – Trial courts in the circuit have guidance that a special verdict form can compensate for less-than-perfect oral instructions, though the panel signaled the pattern instructions are the safer path.
Vagueness challenges narrowed – Defendants cannot piggy-back a vagueness attack on a regulation that merely supplies background context for a false-statement charge.

Complex Concepts Simplified

18 U.S.C. § 371 (“Conspiracy to commit offense”): Penalizes agreements to commit any federal crime plus an overt act. The “object” must itself be a defined federal offense.
18 U.S.C. § 1001(a)(3): Makes it a felony to make or use a false writing in any matter within federal jurisdiction. “Use” can be as simple as handing over a document that carries an implicit representation of accuracy.
Plea Factual Statement: A narrative of facts embedded in a plea agreement. When a defendant swears to its truth during a plea hearing, it becomes his own prior testimony, admissible under Rule 801(d)(1)(A) if later inconsistent.
Aiding and Abetting (18 U.S.C. § 2): Treats one who facilitates or encourages a crime as liable as the principal. Requires (i) affirmative assistance and (ii) intent to promote the offense—not completion of every element.
Materiality (Fraud): A falsehood is “material” if it naturally could influence the victim’s decision, or goes to “the essence of the bargain.” Courts use either formulation; both were satisfied here.

Conclusion

United States v. Clark & Mesner delivers a multipart lesson in white-collar criminal procedure. Most notably, it cements the principle that a § 371 conviction lives or dies on the presence of a live, specifically instructed predicate offense for each conspirator. Simultaneously, it lowers the bar for proving “use” of a false document under § 1001(a)(3) through aiding-and-abetting theory and gives prosecutors a green light to deploy plea factual statements as substantive evidence. Trial courts receive guidance on the adequacy of unanimity instructions and the limited scope of vagueness attacks when defendants are charged with deception, not regulatory violation. For practitioners, the case is both a cautionary tale—illustrating the evidentiary and procedural snares that can unwind convictions—and a strategic roadmap for future environmental, workplace-safety, and fraud prosecutions in the Seventh Circuit and beyond.