United States v. Muñoz-Gonzalez: Stipulated-Facts Advocacy & Plain-Error Waiver in Breach-of-Plea Claims

Introduction

United States v. Muñoz-Gonzalez, No. 22-1423 (1st Cir. July 17 2025), addresses two increasingly recurrent questions in federal criminal procedure: (1) How far may prosecutors go during sentencing advocacy without breaching a plea agreement, particularly when the agreement already contains a detailed factual stipulation but a pared-down Guidelines calculation; and (2) What are the consequences when a defendant alleges a breach but fails to frame the argument explicitly under the plain-error rubric in his opening appellate brief?

The appellant, Derek Muñoz-Gonzalez, pled guilty to two counts of child-pornography production. In exchange, the government dismissed distribution and possession counts and promised to recommend a sentence not exceeding 276 months, inside a jointly calculated Guidelines range of 262-327 months. The agreement also contained an expansive waiver-of-appeal clause effective if the court imposed 327 months or less. At sentencing the prosecutor reiterated the 276-month recommendation but, in explaining the request, highlighted stipulated facts (sexual contact with an eight-month-old and sharing of images) that had not been used in the Guidelines computation. The district court imposed 327 months — the top of the range yet within the appeal waiver. Muñoz appealed, alleging a governmental breach and insisting the appeal waiver did not bar that claim.

Summary of the Judgment

The First Circuit affirmed the 327-month sentence.
Because the defendant did not allege breach during sentencing and did not invoke the plain-error standard in his opening brief, the alleged breach claim was deemed waived.
Even if not waived, the Court found no “clear or obvious” breach: the prosecutor’s reliance on stipulated facts to justify the agreed-upon 276-month recommendation was “reasonably consistent” with the plea bargain and permissible rebuttal to the defense’s lower-sentence request.
Having found no breach, the panel declined to decide whether the broad waiver-of-appeal clause would have separately barred the challenge.

Analysis

1. Precedents Cited & Their Influence

United States v. Lessard, 35 F.4th 37 (1st Cir. 2022) — Reiterated the “meticulous standards of promise and performance” governing plea agreements. The Court borrowed its “totality of the circumstances” framework and notion that defendants are entitled to the “benefit of the bargain.”
United States v. Montañez-Quiñones, 911 F.3d 59 (1st Cir. 2018) — Emphasized the government’s “right (indeed, duty)” to explain why its recommended sentence is appropriate when the plea permits divergent recommendations. This authority underpinned the Court’s acceptance of the prosecutor’s detailed allocution.
United States v. Mulkern, 49 F.4th 623 (1st Cir. 2022); United States v. Pabon, 819 F.3d 26 (1st Cir. 2016) — Confirmed that issues subject to plain-error review are waived unless the appellant addresses each prong in his opening brief. These cases supplied the doctrinal hook for the waiver ruling.
United States v. Miranda-Martínez, 790 F.3d 270 (1st Cir. 2015) and United States v. Cruz-Vázquez, 841 F.3d 546 (1st Cir. 2016) — Held that recounting undisputed facts relevant to sentencing does not breach a plea bargain so long as the government adheres to its explicit recommendations.
Other supportive authorities — Acevedo-Osorio (2024); Cortés-López (2024); Davis (2019); Rivera-Ruiz (2022) — fleshed out the standards for breach and plain-error review.

2. The Court’s Legal Reasoning

Standard of Review – Plain Error. The panel first determined that because Muñoz raised no breach objection below, plain-error review applied. Under Ruiz-Huertas, the burden rests on the appellant to establish (i) error, (ii) that is clear or obvious, (iii) affects substantial rights, and (iv) seriously impugns the proceeding’s integrity.
Procedural Waiver. Citing Mulkern, the Court held that Muñoz’s failure to analyze the four-prong test in his opening brief automatically forfeited the claim, rendering the alleged error unreviewable.
No “Clear or Obvious” Breach. In dicta, the panel explained that even if evaluated on the merits, the prosecutor’s conduct complied with the agreement. The government:
- Reaffirmed the promised 276-month recommendation.
- Quoted verbatim the plea’s factual stipulation rather than introducing new or unagreed facts.
- Spoke in rebuttal to defense counsel’s request for the bottom of the range, a context the First Circuit has repeatedly deemed permissible.
Thus, no “end-run” around the plea bargain occurred.
Unreached Appeal-Waiver Question. Having found no breach, the Court found it unnecessary to decide if the waiver-of-appeal clause independently barred the appeal. This preserves space for future litigation over whether a breach claim automatically circumvents broad waivers.

3. Impact of the Decision

Sentencing Advocacy Clarified. Prosecutors may safely draw the court’s attention to stipulated, though unscored, facts to defend their agreed-upon recommendation, provided they do not urge enhancements or sentences beyond the bargain.
Plain-Error Practice Tightened. The decision intensifies the existing expectation that appellants explicitly walk through all four plain-error prongs in their opening briefs. Omitting that structure now nearly guarantees waiver in the First Circuit.
Plea-Agreement Drafting & Litigation Strategy.
- Defense counsel must ensure that every fact the prosecutor might rely on is either (a) incorporated in the Guidelines calculation or (b) expressly cabined in the agreement if they wish to foreclose it at sentencing.
- On appeal, practitioners must treat breach allegations as plain-error claims whenever no contemporaneous objection was made.
Future Cases. Expect increased government citation of Muñoz-Gonzalez when defending plea-breach allegations in which the prosecutor stuck to the recommendation but recited lurid, stipulated facts. Defendants, conversely, will need either an on-the-record objection or a meticulously crafted opening-brief plain-error analysis.

Complex Concepts Simplified

Plea Agreement: A written contract between the defendant and the government where the defendant agrees to plead guilty in exchange for concessions (e.g., dismissal of other counts, sentencing recommendations).
Breach of Plea Agreement: When either side fails to perform a material promise contained in the agreement, the other side can seek relief such as specific performance (resentencing) or withdrawal of the plea.
Plain-Error Review (Fed. R. Crim. P. 52(b)): An appellate standard applied to unpreserved errors. The appellant must show (1) error, (2) that is clear or obvious, (3) affects substantial rights, and (4) seriously affects the fairness or integrity of the proceedings.
Waiver-of-Appeal Clause: A plea-agreement term in which the defendant voluntarily gives up the right to appeal part or all of the conviction or sentence, typically subject to listed exceptions (e.g., illegal sentence, breach by the government).
Guidelines Enhancements: Specific offense-characteristic increases to the base offense level under the U.S. Sentencing Guidelines, typically triggered by aggravating factors such as the victim’s age or the defendant’s distribution conduct.

Conclusion

United States v. Muñoz-Gonzalez crystallizes two practical teachings: (1) A prosecutor who remains within the four corners of the plea bargain — both in recommendation and factual recitation — does not breach the agreement by emphasizing disturbing, yet stipulated, facts; and (2) Appellate counsel must front-load a full plain-error analysis in their opening brief or risk automatic procedural waiver. As the First Circuit continues to police both plea-agreement integrity and briefing rigor, Muñoz-Gonzalez will serve as a touchstone for litigants navigating the delicate boundary between zealous sentencing advocacy and contractual overreach, while simultaneously reinforcing a stringent approach to issue preservation on appeal.