Perfunctory Briefing Waives Most Appellate Issues; Severance Requires Concrete “Actual Prejudice” Beyond Spillover Evidence

I. Introduction

In United States v. Lin (10th Cir. July 24, 2026) (unpublished “Order and Judgment”), the Tenth Circuit affirmed Naiqing Lin’s conviction for conspiracy to distribute a controlled substance under 21 U.S.C. §§ 841(a)(1), 846. Lin was charged in a multi-defendant prosecution arising from a federal investigation into an organization that cultivated marijuana in “grow houses” and distributed it nationwide, alongside alleged money laundering activity.

Lin raised seven appellate issues, but the panel held that five were waived due to inadequate briefing and/or an insufficient appellate record. The court reached the merits only on (1) the denial of Lin’s motion to sever and (2) the sufficiency of the evidence supporting the drug-trafficking conspiracy conviction.

II. Summary of the Opinion

  • Waiver: The panel declined to consider five claims because Lin’s opening brief failed to present developed argument, correct standards of review, supporting authority, or a record adequate for review.
  • Severance: The district court did not abuse its discretion in denying severance because Lin failed to show “actual prejudice outweighing the expense and inconvenience of separate trials.”
  • Sufficiency: Viewing the evidence in the light most favorable to the government, a rational jury could find all elements of the drug-trafficking conspiracy proved beyond a reasonable doubt based chiefly on testimony describing Lin’s paid work in the organization (maintenance, cultivation support, transportation, packaging, and interaction with buyers).

III. Analysis

A. Precedents Cited (and How They Shape the Outcome)

1. Waiver for Inadequate Briefing / Inadequate Record

  • United States v. Wooten, 377 F.3d 1134, 1145 (10th Cir. 2004): The opinion uses Wooten’s rule to justify declining review of issues presented “in a perfunctory manner” without developed argumentation. This becomes the backbone for trimming the appeal from seven issues to two.
  • United States v. Cooper, 654 F.3d 1104, 1128 (10th Cir. 2011): Cited for the “well-settled” proposition that inadequately briefed arguments in the opening brief are waived, reinforcing that waiver is an appellate discipline mechanism, not a merits determination.
  • Fed. R. App. P. 28(a)(8)(A) and Fed. R. App. P. 28(a)(8)(B): The panel treats these as enforceable briefing obligations—requiring reasons, authorities, record citations, and a standard of review for each issue.
  • United States v. Clay, 148 F.4th 1181, 1201 (10th Cir. 2025): Invoked to reiterate that undeveloped, citation-free, perfunctory assertions are not enough. Clay operationalizes Rule 28 by explaining what “developed argumentation” looks like in the Tenth Circuit.
  • 10th Cir. R. 10.4(B): Applied to reject Lin’s jury-note claim and PSR-quantity challenge because he did not supply a record/appendix sufficient to evaluate them. The court treats record preparation as the appellant’s burden.
  • United States v. Archuleta, 737 F.3d 1287, 1296 (10th Cir. 2013): Used to anchor the governing standard—unobjected-to evidentiary claims are reviewed only for plain error.
  • United States v. Finnesy, 953 F.3d 675, 684 (10th Cir. 2020) and United States v. Cordery, 656 F.3d 1103, 1105 (10th Cir. 2011): These supply the four-part plain error framework and the discretionary fourth prong. Lin’s failure to engage the framework is treated as waiver.
  • Bacote v. Fed. Bureau of Prisons, 119 F.4th 808, 814 (10th Cir. 2024) and United States v. Ruiz- Gea, 340 F.3d 1181, 1187 (10th Cir. 2003): Cited to explain why out-of-circuit authority (here, Fifth Circuit cases) does not establish “plainness” in the Tenth Circuit; “plain” generally requires Supreme Court or Tenth Circuit precedent.

2. Severance (Rule 14) and the “Actual Prejudice” Threshold

  • United States v. Clark, 717 F.3d 790, 818 (10th Cir. 2013): Provides the abuse-of-discretion standard of review for denial of severance.
  • United States v. Landers, 564 F.3d 1217, 1224 (10th Cir. 2009): Defines abuse of discretion as “arbitrary, capricious, whimsical, or manifestly unreasonable,” setting a high bar for reversal.
  • United States v. Garcia, 74 F.4th 1073, 1110 (10th Cir. 2023) and United States v. Herrera, 51 F.4th 1226, 1271 (10th Cir. 2022): These frame Rule 14(a) severance as exceptional—requiring “actual prejudice” that outweighs the inefficiency of separate trials. The panel uses this balancing formulation to reject generalized complaints about “overflow” evidence.
  • United States v. Caldwell, 560 F.3d 1214, 1221 (10th Cir. 2009): Central to the severance holding: negative “spill-over” from damaging evidence against a co-defendant is not enough by itself. Lin’s “overflow of evidence” argument is treated as precisely the sort Caldwell deems insufficient.
  • United States v. Hill, 786 F.3d 1254, 1272 (10th Cir. 2015): Discussed in a footnote to explain liberal joinder principles under Rule 8 and the court’s preference for efficiency; even if Lin had properly raised misjoinder, the court signals the claim would fail.

3. Sufficiency of the Evidence (Drug Conspiracy)

  • United States v. Flechs, 98 F.4th 1235, 1242 (10th Cir. 2024): Supplies de novo review for sufficiency challenges.
  • United States v. Sells, 477 F.3d 1226, 1235 (10th Cir. 2007) and United States v. King, 632 F.3d 646, 650 (10th Cir. 2011): Reinforce that the court views evidence in the government’s favor and does not reweigh credibility; juries receive “considerable deference.”
  • United States v. Ramos-Arenas, 596 F.3d 783, 786 (10th Cir. 2010) and United States v. Brown, 400 F.3d 1242, 1247 (10th Cir. 2005): State the stringent reversal standard: only if no rational trier of fact could find guilt beyond a reasonable doubt.
  • United States v. Renteria, 720 F.3d 1245, 1253 (10th Cir. 2013) and United States v. Hernandez, 509 F.3d 1290, 1295 (10th Cir. 2007): Provide the controlling elements for a drug-trafficking conspiracy: agreement, knowledge of objectives, knowing/voluntary involvement, and interdependence. The panel maps testimony about Lin’s paid tasks to these elements.
  • United States v. Woodmore, 127 F.4th 193, 219 (10th Cir. 2025): Used to reject Lin’s attempt to convert conflicting testimony into insufficiency; inconsistency does not itself defeat a verdict.

B. Legal Reasoning

1. The Court Treats Appellate Procedure as Merits-Determinative

A key feature of the decision is that it is less about novel substantive criminal law than about enforcement of appellate gatekeeping rules. By applying Fed. R. App. P. 28, the plain-error rubric, and 10th Cir. R. 10.4(B), the panel narrows the scope of review to claims that are properly presented and supported. In effect, the opinion reaffirms that appellate courts decide cases based on the arguments and record the parties provide; they do not reconstruct missing record materials or build legal theories for appellants.

2. Severance: “Overflow” Evidence Is Not “Actual Prejudice” Without Particularized Harm

On severance, the panel uses the Rule 14(a) balancing test (as articulated in United States v. Garcia and United States v. Herrera) and then applies United States v. Caldwell to dispose of Lin’s core theory. Lin asserted generalized “overflow” (spillover) prejudice but did not identify a concrete mechanism by which the joint trial prevented the jury from making a reliable individualized determination of his guilt—nor did he show why any risk could not be cured by ordinary trial management (e.g., separate consideration instructions) or why it outweighed the inefficiency of separate trials.

3. Sufficiency: Paid Operational Work Supports the Elements of Conspiracy

The sufficiency analysis is a straightforward application of the Renteria element test under deferential evidentiary review rules. Two witnesses—Naigang (a cooperating participant) and Lyu—described Lin as a paid worker who performed recurring, functional tasks: tending plants, property conversion to grow houses, transportation/deliveries, packaging, and buyer interaction. From those facts, the panel holds a rational jury could infer:

  • Agreement: Lin’s repeated participation in coordinated grow-house operations supports an inference of an agreement.
  • Knowledge of objectives: Tasks directly tied to cultivation, processing, delivery, and sales support knowledge.
  • Knowing/voluntary involvement: Payment and ongoing responsibilities support voluntariness and intent.
  • Interdependence: Operational roles (maintenance, transport, packaging, buyer contact) are mutually reinforcing within a distribution enterprise.

Lin’s counterarguments—vagueness, inconsistency, confusion—are treated as credibility and weight arguments foreclosed by the sufficiency standard (United States v. Sells; United States v. Woodmore).

C. Impact

  • Appellate practice in the Tenth Circuit: The decision underscores that failure to provide the correct standard of review, to develop argument with authority, or to compile an adequate appendix can be outcome-determinative. Litigants should expect the court to enforce Rule 28 and 10th Cir. R. 10.4(B) strictly.
  • Severance motions in conspiracy cases: The ruling reiterates the institutional preference for joint trials in multi-defendant conspiracies and clarifies that “spillover” rhetoric—without concrete, record-based demonstration of actual prejudice—will rarely justify severance.
  • Drug conspiracy proof: Operational participation plus compensation can provide a sufficient evidentiary basis for conspiracy elements, even where the defendant characterizes his role as minor and points to conflicting testimony.
  • Precedential weight: As an unpublished “Order and Judgment,” it is “not binding precedent” (outside law-of-the-case, res judicata, and collateral estoppel), but it may carry persuasive value—particularly on briefing/record sufficiency and routine severance/sufficiency applications.

IV. Complex Concepts Simplified

Waiver vs. plain error review
If an issue is not properly developed on appeal (missing argument, authority, record citations, or standard of review), the court may treat it as waived and decline to consider it. If an issue was not objected to at trial, it is typically reviewed only for plain error, which requires satisfying a four-part test (error, plainness, effect on substantial rights, and discretionary correction to protect the fairness/integrity of proceedings).
Severance under Rule 14(a)
Co-defendants are often tried together. A defendant must show actual prejudice from a joint trial—more than the fact that evidence against a co-defendant is damaging or plentiful. Courts also weigh the public costs of separate trials.
Sufficiency of the evidence
This is not a “who was more believable?” inquiry. The court asks whether any rational jury could find guilt beyond a reasonable doubt when the evidence is viewed in the government’s favor, without reweighing conflicts in testimony.
Interdependence in conspiracy law
Interdependence means the participants’ roles fit together in a way that advances a shared criminal objective—e.g., cultivation, maintenance, transport, packaging, and sales functions operating as parts of one distribution enterprise.

V. Conclusion

United States v. Lin is a procedural and evidentiary sufficiency decision with clear practical lessons: appellants must present developed arguments with the correct standards of review and a complete record; severance requires a concrete showing of “actual prejudice” beyond generalized spillover claims; and, under deferential sufficiency review, testimony describing paid, operational participation in a drug enterprise can support a conspiracy conviction even amid conflicting evidence.