Plain-Error Relief Denied When Permissible Factors Independently Support a Vulnerable-Victim Enhancement

1. Introduction

United States v. Moss (10th Cir. July 20, 2026) addresses how appellate courts evaluate an unpreserved challenge to the vulnerable victim sentencing enhancement under U.S.S.G. § 3A1.1(b)(1) when the sentencing court relied on a mix of impermissible and permissible factors.

The defendant, Kendall Joseph Moss III, was convicted of sexually abusing a ten-year-old girl, in violation of 18 U.S.C. § 2244(a)(5). The victim met Moss in a group home where he worked, and later lived with him after he took her in as a foster child. At sentencing, the district court adopted the presentence report’s recommendation to apply the vulnerable-victim enhancement, increasing the advisory guideline range to 63–78 months. The court nonetheless varied downward and imposed 57 months in prison and 15 years of supervised release.

On appeal, Moss argued the enhancement was improperly based in part on characteristics already accounted for elsewhere in the guideline calculation (a form of prohibited “double counting” under the guideline commentary). The central question became: even if some relied-upon factors were impermissible, does the error warrant relief when other permissible factors independently justify the enhancement—particularly under plain-error review?

2. Summary of the Opinion

The Tenth Circuit affirmed. Assuming (without deciding) the issue was not waived, the court applied the plain-error framework and focused on whether any error affected Moss’s substantial rights. It held that Moss failed to show a reasonable probability the district court would have declined to apply the vulnerable-victim enhancement had it relied only on permissible considerations.

Although the presentence report and sentencing court referenced two arguably impermissible factors—(1) the victim’s age and (2) Moss’s custodial status as foster parent—those factors were also already incorporated through separate guideline enhancements. But the district court also relied on two permissible factors recognized in Tenth Circuit precedent:

  • a size disparity between Moss and the victim, and
  • the victim’s unstable home life and Moss’s knowledge of her emotional vulnerabilities.

Because these permissible factors could independently support the enhancement, Moss could not meet the plain-error requirement of demonstrating a reasonable probability of a different outcome.

3. Analysis

3.1. Precedents Cited

  • United States v. Wolfname, 835 F.3d 1214, 1217 (10th Cir. 2016)
    Role in Moss: Wolfname is cited for the proposition that, absent waiver, an error is “plain” only if the defendant shows the error affected substantial rights. In Moss, this frames the appellate burden: it is not enough to identify an arguable guideline mistake; the appellant must show a meaningful likelihood that the sentence would have changed.
  • United States v. Booker, 63 F.4th 1254, 1262 (10th Cir. 2023)
    Role in Moss: Booker supplies the governing definition of “substantial rights” in the sentencing context: the defendant must establish a reasonable probability of a different result absent the error. Moss applies this directly: the panel asks whether the vulnerable-victim enhancement likely would have been denied had the court excluded the impermissible factors.
  • United States v. Checora, 175 F.3d 782, 789 (10th Cir. 1999)
    Role in Moss: Checora is used to validate size disparity as a legitimate indicator of unusual vulnerability. Moss treats size difference as conceptually distinct from age: the enhancement was supported not simply because the victim was young, but because Moss’s exceptional height/weight amplified the victim’s susceptibility in a way not already captured by the age-based guideline increase.
  • United States v. Sumka, 81 F.4th 1153, 1159 (10th Cir. 2023)
    Role in Moss: Sumka supports using a victim’s unstable home life as a permissible basis for vulnerability. Moss extends the logic by emphasizing the defendant’s knowledge of that instability and the victim’s emotional difficulties, which could increase the defendant’s power and the victim’s susceptibility.
  • United States v. Tissnolthtos, 115 F.3d 759, 761-62 (10th Cir. 1997)
    Role in Moss: Tissnolthtos is invoked to show that vulnerability analysis can consider not only the victim’s traits but also information about the defendant (here, Moss’s “unusual height and weight”). This helps the panel rebut Moss’s argument that size disparity is merely a proxy for the victim’s age.
  • United States v. Scott, 529 F.3d 1290, 1301-03 (10th Cir. 2008)
    Role in Moss: Scott is central to the court’s confidence in affirmance. Scott held that even where a defendant preserved a challenge to a vulnerable-victim enhancement, reliance on impermissible factors can be treated as harmless when other permissible factors justify the enhancement. Moss analogizes: if the court does not reverse in the preserved/harmlessness context where independent grounds exist, it makes even less sense to reverse under the more demanding plain-error standard for an unpreserved challenge.
  • United States v. Farley, 36 F.4th 1245 (10th Cir. 2022) and United States v. Cordery, 656 F.3d 1103 (10th Cir. 2011)
    Role in Moss: Moss cites these cases for the idea that courts should focus on the factors a district court emphasized. The panel distinguishes both as not involving a guideline enhancement: Farley addressed an erroneous variance, and Cordery involved reliance on an improper sentencing factor. Because those contexts differ, they do not alter the Scott-style inquiry applied here (whether permissible factors independently support the enhancement).

3.2. Legal Reasoning

(a) The guideline “double counting” problem and Application Note 2

The vulnerable-victim enhancement, U.S.S.G. § 3A1.1(b)(1), is limited by U.S.S.G. § 3A1.1, cmt. n.2, which states the enhancement does not apply if the factor that makes the victim vulnerable is already incorporated in the offense guideline.

Moss argued the district court improperly relied on:

  • Age: already reflected by the enhancement in U.S.S.G. § 2A3.4(b)(1) (victim under twelve).
  • Custody status: already reflected by U.S.S.G. § 2A3.4(b)(3) (defendant’s custodial role).

The panel did not definitively decide whether relying on these considerations was error; instead, it assumed arguendo and moved to the dispositive question under plain-error review: whether any such error likely changed the result.

(b) Plain-error focus on “substantial rights”

Because Moss did not object in district court, the appeal turned on the substantial-rights prong: Moss had to show a reasonable probability that the enhancement would not have been applied if the district court had excluded the impermissible factors. The court held he failed to carry that burden.

(c) Independent, permissible grounds supported the enhancement

The panel emphasized two permissible factors that were not simply duplicative of age or custodial status:

  • Size disparity: the court relied on the difference between the child’s size and Moss’s (6'3", 340 lbs), not solely the fact of childhood. Under Checora and Tissnolthtos, this kind of disparity can make a victim unusually susceptible in ways not already captured by the base guideline and age enhancement.
  • Unstable home life plus defendant’s knowledge: the court relied on more than the fact that instability led to foster placement (which could overlap with custodial-status adjustments). It relied on Moss’s knowledge of the victim’s troubled past and emotional problems, supporting an inference that this knowledge increased his power and her vulnerability. Sumka supports this type of consideration.

(d) The court declined to reweigh which factors were “emphasized”

Moss argued the district court relied “heavily” on impermissible considerations. The panel responded by applying the logic of United States v. Scott: when permissible factors independently justify the enhancement, appellate reversal is unwarranted even if impermissible factors were also mentioned—particularly where the defendant failed to preserve the objection.

3.3. Impact

  • Appellate burden in unpreserved guideline challenges: Moss reinforces that defendants challenging a guideline enhancement on appeal without a contemporaneous objection face a steep climb. Identifying an arguable “double counting” issue is insufficient; the defendant must show the outcome likely would have differed.
  • Resilience of enhancements supported by multiple facts: Where the record contains at least one (and especially multiple) independently valid bases for a vulnerable-victim enhancement, Moss suggests the enhancement will often be affirmed under plain-error review—even if the sentencing court’s explanation also includes improper or duplicative considerations.
  • Practical sentencing implications: Sentencing litigants should expect appellate courts in the Tenth Circuit to ask a forward-looking, outcome-focused question: “Would the enhancement still stand on permissible grounds?” This encourages defense counsel to object specifically at sentencing to preserve full review and to force clarification of the exact grounds the court is relying upon.
  • Doctrinal clarification (persuasive, not binding): The decision is an “Order and Judgment” and thus not binding precedent (except under law-of-the-case, res judicata, and collateral estoppel). Nonetheless, it provides persuasive guidance on how panels may approach mixed-factor vulnerability findings under plain-error review.

4. Complex Concepts Simplified

  • “Vulnerable victim” enhancement (U.S.S.G. § 3A1.1(b)(1)): An increase in the guideline offense level when a victim is unusually vulnerable (for example, due to physical or emotional conditions) and the defendant knew or should have known of that vulnerability.
  • “Double counting” in guidelines: Using the same factual trait to increase the sentence twice under different guideline provisions. The guideline commentary here warns against applying the vulnerable-victim enhancement when the very same vulnerability has already been accounted for elsewhere in the guideline calculation.
  • Plain-error review: A stricter appellate standard applied when the defendant did not object in the trial court. Among other things, the defendant must show the error likely changed the outcome.
  • “Substantial rights” (in this context): A defendant’s burden to show a reasonable probability that, without the alleged mistake, the sentence would have come out differently.
  • Harmless error vs. plain error: “Harmless error” often applies to preserved issues and asks whether the error mattered. “Plain error” applies to unpreserved issues and is harder for defendants, requiring a clearer showing of prejudice (and other requirements not reached here).

5. Conclusion

United States v. Moss establishes (as persuasive Tenth Circuit authority) a practical rule for unpreserved challenges to the vulnerable-victim enhancement: even if a sentencing court referenced some impermissible, duplicative factors, a defendant cannot obtain plain-error relief when other permissible factors independently justify the enhancement and the defendant cannot show a reasonable probability of a different outcome.

The opinion’s broader significance is its emphasis on outcome confidence: appellate courts will not reverse merely because the sentencing rationale included some improper considerations, so long as valid, independent grounds remain that support the same enhancement—especially where the defendant failed to object at sentencing.