Alternative Factual Theories as Waiver Triggers in Proffer Agreements: Commentary on United States v. Steve Bonner

Alternative Factual Theories as Waiver Triggers in Proffer Agreements: Commentary on United States v. Steve Bonner

I. Introduction

The Eleventh Circuit’s unpublished decision in United States v. Steve (Scott) Bonner, No. 24-11426 (11th Cir. Nov. 19, 2025), deals with a recurring and practically important problem in federal criminal practice: when, and how broadly, a defendant’s statements made under a proffer agreement can be used against him at trial under a contractual waiver provision.

The case arises from a long-running theft and resale scheme involving high-value government-owned night-vision and optical devices—AN/PVS-30 scopes (“PVS-30s”) and Advanced Combat Optical Gunsights (“ACOGs”)—stolen from the Anniston Army Depot in Alabama. A group of law-enforcement officers abused their positions to steal equipment worth roughly $4 million, which they resold or otherwise disposed of through various channels. Bonner was prosecuted as a middleman who allegedly acquired stolen scopes and passed them to a surplus store owner and others for resale.

Before being indicted, Bonner entered into a written proffer agreement with the government, under which he made inculpatory admissions in two separate proffer sessions. The agreement conferred limited “use immunity” for those statements, but—crucially—contained an express waiver clause permitting the government to use his proffer statements to impeach him or to “rebut any evidence or argument” he later offered at trial or sentencing.

At trial on a conspiracy charge under 18 U.S.C. § 371, the district court concluded that Bonner’s opening statement and cross-examination of government witnesses had triggered this waiver clause, thereby allowing the government to introduce fourteen specified statements from the proffer sessions as rebuttal evidence. Bonner was convicted and sentenced to 30 months’ imprisonment and over $1.8 million in restitution.

On appeal, Bonner argued that:

  • the district court misinterpreted the waiver provision in his proffer agreement, and
  • even if interpreted correctly, the court abused its discretion in finding that his defense strategy at trial actually triggered the waiver and justified admitting the fourteen proffer statements.

The Eleventh Circuit rejected both arguments and affirmed. Although the opinion is designated “Not for Publication” and therefore non-precedential, it is a detailed application of existing Eleventh Circuit and other circuit authority to a common proffer-agreement template. It clarifies how defense theories presented in opening statements and cross-examination can “open the door” to the use of proffer statements under a waiver clause, even where the defendant never takes the stand.

II. Summary of the Opinion

The panel (Judges Jill Pryor, Luck, and Brasher) affirmed Bonner’s conviction, focusing on two core issues:

  1. Interpretation of the waiver clause in the proffer agreement; and
  2. Application of that clause to Bonner’s conduct at trial.

First, the court reviewed de novo the proffer agreement’s waiver provision, which allowed the government to use Bonner’s proffer “statements or information”:

“to rebut any evidence or argument offered by him or on his behalf in connection with any trial and/or sentencing.”

The panel held that, applying contract-law principles as adapted to criminal cases, the waiver clearly functioned as an exception to the general promise of use immunity and permitted the government to introduce specific portions of the proffer necessary to rebut defense evidence or argument. It approved the district court’s narrower reading: the waiver did not open the entire proffer file; it allowed only those parts that directly rebutted what Bonner put before the jury.

Second, the panel reviewed for abuse of discretion the district court’s ruling that Bonner’s opening statement and cross-examination had in fact triggered this waiver and justified admission of fourteen discrete proffer statements. The court emphasized:

  • Bonner’s opening statement advanced an alternative factual theory: he was just a “fix-it guy” who repaired scopes, believed his co-conspirator had permission to take them, and did not financially benefit from any unlawful conspiracy.
  • His cross-examination of government witnesses elicited testimony to support that theory (e.g., that he repaired scopes, that he was told the items were authorized, and that his profit was uncertain or minimal).

These moves, the court held, went beyond a mere attack on witness credibility or the sufficiency of the government’s evidence. Instead, they implicitly asserted that:

  • Bonner did not know the scopes were stolen,
  • he received them only for repair, and
  • he did not meaningfully profit from any criminal scheme.

Those implicit factual claims directly contradicted Bonner’s own prior proffer statements, where he admitted, among other things, that he knew the items with CAGE numbers were government property, that he knowingly bought substantial quantities of stolen scopes from co-conspirator Battle, and that he was involved in substantial volumes of unlawful transactions.

The panel, relying on Eleventh Circuit precedent and supportive decisions from the Second and Fifth Circuits, held that this kind of alternative factual theory—put before the jury via opening and cross, not just via defendant testimony—was sufficient to trigger the waiver and allow the government to introduce the conflicting proffer statements as rebuttal evidence. Finding no clear error of judgment in the district court’s careful, statement-by-statement approach, the court affirmed.

III. Detailed Analysis

A. Legal Framework: Proffer Agreements, Use Immunity, and Waiver

A proffer agreement (often called a “queen-for-a-day” letter) is a written agreement under which a suspect or target, typically through counsel, agrees to speak candidly with prosecutors and agents about their own conduct and that of others. In exchange, the government usually promises some form of limited immunity for the statements made in the proffer session.

In Bonner’s case, the government promised:

“[n]o [s]tatement made by [Bonner] or other information provided by [him] during the proffer will be used by the [g]overnment against [him] in any criminal or civil proceeding[.]”

But this promise was explicitly subject to several exceptions. One critical exception was the waiver provision:

“In the event that you appear as a witness at any judicial proceeding or submits [sic] any oral or written statement in conjunction with any future trial and/or sentencing, any statements or information provided during this proffer may be used for cross-examination and impeachment. In addition, such statements or information may be used to rebut any evidence or argument offered by him or on his behalf in connection with any trial and/or sentencing.”

Thus, the prosecution gained two tools:

  1. Impeachment/cross-examination: If Bonner testified or submitted a statement, the government could use his proffer statements to impeach him.
  2. Rebuttal: Even if he did not testify, the government could use the proffer statements “to rebut any evidence or argument” offered “by him or on his behalf.”

Bonner concerns this second, broader component—the “rebut any evidence or argument” clause—and asks: What counts as “evidence or argument” by or on behalf of the defendant that is sufficient to trigger this waiver?

B. Interpretation of the Waiver Provision

1. Applicable interpretive principles

The Eleventh Circuit applied its established framework for construing proffer agreements:

  • They are interpreted using principles of contract law, as adapted to the criminal context. (United States v. Blanco, 102 F.4th 1153, 1163 (11th Cir. 2024); United States v. Pielago, 135 F.3d 703, 709 (11th Cir. 1998); United States v. Hill, 643 F.3d 807, 874 (11th Cir. 2011).)
  • But the court cautions that the contract analogy “should not be taken too far,” and that “a hyper-technical reading of the written agreement and a rigidly literal approach … should not be accepted.” (Blanco quoting Pielago.)
  • The agreement must be read in light of the parties’ negotiations and purposes, not as an abstract commercial contract.
  • Ambiguities in a proffer agreement are resolved in favor of the defendant. (Blanco, Pielago.)

This approach reflects the hybrid nature of proffer letters: they are contracts, but they directly implicate a defendant’s constitutional rights and liberty. Courts therefore interpret them more protectively than, say, a commercial lease.

2. The Pielago analogy

The panel pays particular attention to United States v. Pielago, which it uses as a template for reconciling overlapping clauses in a proffer agreement. In Pielago, the agreement contained:

  • a broad promise that “[n]o information or statement” provided by the defendant “may be used against [her] in this case or any other criminal investigation,” and
  • a reservation of the government’s right to “pursue any and all investigative leads derived from [her] statements or information and use such derivative evidence in any criminal or civil proceeding against her and/or others.”

The defendant there argued that using her statements to indict a co-conspirator (who then testified against her) violated the ban on using her information “against her.” The Eleventh Circuit, applying contract principles, concluded:

  • In the broadest sense, the government had indeed used her information “against” her, because it helped generate incriminating testimony.
  • But the two paragraphs could be harmonized by reading the derivative-evidence clause as a qualification of the general no-use promise, not as a contradiction.

That method—harmonizing apparent tension by treating specific exceptions as qualifications of general promises—informs the court’s reading of Bonner’s agreement.

3. Application to Bonner’s waiver clause

The court first characterizes the waiver clause as an express exception to the general use-immunity provision:

“[Bonner’s] proffer agreement stated that the waiver provision was an exception to the promise not to use his proffer statements against him in criminal proceedings.”

It then focuses on the key phrase “statements or information” and the restriction that such material may be used “to rebut any evidence or argument offered by him or on his behalf.” The district court, and the Eleventh Circuit, read this to mean:

  • The government may introduce only those specific portions of the proffer statements that are necessary to rebut what the defense has put at issue.
  • The waiver does not permit the government to wholesale introduce everything Bonner said in his proffer sessions.

The appellate court expressly endorses the district court’s approach:

“Applying those principles, the district court correctly read the waiver provision to permit the government to introduce only the specific portions of the ‘statements or information’ to which Bonner had opened the door to rebuttal. We see no error in the district court’s interpretation of the waiver provision.”

Thus, the opinion:

  • rejects Bonner’s contention that the district court adopted an “overly expansive” view of the waiver; and
  • approves a targeted rebuttal-only model for using proffer statements under such clauses.

In doctrinal terms, the court reinforces that a use-immunity clause plus an explicit rebuttal/waiver clause must be read together, with the waiver operating as a specific qualification of the general immunity promise, consistent with Pielago.

C. Admission of the Proffer Statements as Rebuttal Evidence

1. Standard of review and general rebuttal principles

The Eleventh Circuit reviews:

  • Interpretation of the proffer agreement de novo (Hill, Blanco), and
  • Evidentiary rulings allowing admission of the proffer statements under that agreement for abuse of discretion. (United States v. Henderson, 409 F.3d 1293, 1297 (11th Cir. 2005); United States v. Frazier, 387 F.3d 1244, 1259 (11th Cir. 2004) (en banc); United States v. Barrow, 400 F.3d 109, 117 (2d Cir. 2005).)

Under the abuse-of-discretion standard:

  • The trial court is given a “range of choice” so long as its decision does not constitute a “clear error of judgment” or rely on the wrong legal standard. (Frazier.)
  • Appellate courts recognize that trial judges “are uniquely situated to assess the impact certain evidence or arguments have made on a jury,” especially in the nuanced realm of rebuttal. (Barrow, quoting United States v. Tejada, 956 F.2d 1256, 1267 (2d Cir. 1992).)

The panel also invokes the Eleventh Circuit’s longstanding view of rebuttal evidence, citing United States v. Gold, 743 F.2d 800, 818 (11th Cir. 1984):

“The purpose of rebuttal evidence is to explain, repel, counteract, or disprove the evidence of the adverse party, and the decision to permit rebuttal testimony is one that resides in the sound discretion of the trial judge.”

And it quotes former Fifth Circuit authority (binding on the Eleventh Circuit for pre-October 1981 decisions) in United States v. Hall, 653 F.2d 1002, 1006 (5th Cir. Unit A 1981):

“when the defendant has opened the door to a line of testimony by presenting evidence thereon, he cannot object to the prosecution’s accepting the challenge and attempting to rebut the proposition asserted.”

With that framework, the question becomes: did Bonner merely attack the sufficiency and credibility of the government’s case (which would not trigger the waiver), or did he affirmatively or implicitly assert factual propositions that contradicted his proffer statements (which would trigger the waiver)?

2. Bonner’s theory: “I only attacked sufficiency and credibility”

On appeal, Bonner argued that his trial conduct:

  • was limited to challenging the sufficiency of the government’s evidence on the elements of the offense, and
  • attacked the credibility of government witnesses.

In his view, those types of arguments fall short of offering “evidence or argument” within the meaning of the waiver clause that would justify admitting his proffer statements; they are simply standard defensive tactics. If accepted, this would sharply limit the scope of such waiver clauses.

3. The Eleventh Circuit’s response: an “alternative factual theory” was presented

The Eleventh Circuit squarely rejects Bonner’s characterization. Instead, the court concludes that Bonner:

  • put forward a coherent alternative factual theory of the case in his opening statement, and
  • reinforced that theory through targeted cross-examination that elicited factual assertions inconsistent with his proffer statements.

The panel identifies three core elements of that alternative theory:

  1. Bonner as a “fix-it guy,” not a criminal middleman.
    In opening, he portrayed himself as an “expert gunman” and “the fix-it guy,” suggesting that his role was to repair scopes, not to participate in theft or unlawful resale. This implied that:
    • he received scopes only for legitimate repair work, and
    • he did not know or participate in any illicit distribution.
  2. Bonner’s alleged belief that Battle had permission.
    He told the jury he expected testimony that co-conspirator Battle had told Bonner he had permission to take the items, pointing toward an absence of criminal intent or knowledge that the items were stolen.
  3. “Follow the money” – lack of profit as evidence of innocence.
    He invited jurors to compare his financial records with those of the conspirators, suggesting that because Bonner did not receive “millions of dollars” or even deposits in large denominations, he was:
    • not a significant participant, and
    • perhaps an unwitting actor rather than a knowing conspirator.

The court characterizes this as more than mere cross-examination or abstract argument about insufficiency:

“This amounted to an alternative factual theory that conflicted with the fourteen proffer statements in which Bonner admitted to knowingly purchasing government-owned scopes for resale that had been taken from Anniston without permission.”

4. Cross-examination reinforcing the alternative theory

The opinion then catalogs how Bonner’s cross-examination of key witnesses reinforced this narrative:

  • He questioned Battle about whether Battle ever told Bonner the items were stolen, inviting Battle to agree that he did not do so.
  • He elicited from Battle and others that Battle had at some point represented having permission to take the items and that distinguishing military from civilian scopes could be difficult—both supporting the idea that Bonner might reasonably have believed the items were legitimate.
  • He pressed Battle on whether Battle knew if Bonner made “a nickel” or “a dollar,” drawing out testimony that Battle could not say Bonner profited—reinforcing the “follow the money” theme.
  • He elicited testimony regarding Bonner’s skill in repairing scopes, further anchoring the “fix-it guy” theory.

The panel concludes that through this questioning:

“Bonner implicitly asserted facts during cross-examination to support his unwitting-conspirator theory of defense, and by doing so, Bonner opened the door to the government's use of whichever proffer statements conflicted with that theory.”

5. Reliance on Barrow (2d Cir.) and Scott (5th Cir.)

The opinion aligns its analysis with persuasive authority from other circuits that have addressed similar waiver language:

  • United States v. Barrow, 400 F.3d 109 (2d Cir. 2005)
    The Second Circuit in Barrow distinguished:
    • cross-examinations that merely challenge witness perception, memory, or credibility, from
    • cross-examinations that implicitly assert that an event did not occur or that a different event occurred.
    When a defense opening and cross-examination implicitly assert factual propositions contrary to the defendant’s proffer, the waiver clause is triggered. The Eleventh Circuit explicitly invokes this distinction.
  • United States v. Scott, 70 F.4th 846 (5th Cir. 2023)
    The Fifth Circuit similarly held that when a defendant offers a “new factual theory” in opening statement that goes beyond sufficiency or credibility attacks, this can trigger a proffer waiver. The Eleventh Circuit cites Scott approvingly and notes that to hold otherwise:
    “would let defendants gut the waiver exceptions in proffer agreements with verbal tricks.”

By relying on Barrow and Scott, the Eleventh Circuit positions Bonner within a developing inter-circuit consensus: defense counsel cannot use opening statements and cross-examination to tell a story inconsistent with a client’s proffer, and then shield the proffer from use under a narrowly literal reading of the waiver clause.

6. The district court’s statement-by-statement approach

Procedurally, the district court took a cautious, granular approach:

  1. It instructed the government pretrial that any attempt to use the proffer statements must be raised outside the jury’s presence, so the court could rule.
  2. After Bonner’s opening and cross, the government renewed its request to admit specific proffer statements as rebuttal, supplying a detailed list.
  3. The court then required the government to go “statement-by-statement” and explain how each particular statement rebutted a specific piece of defense evidence or argument.
  4. Of seventeen statements the government sought to admit, the court allowed fourteen, excluding three.

The Eleventh Circuit takes note of this care and cites it as a reason for deference:

“After reviewing the district court's admissibility rulings and mindful of the time taken by the district court leading up to and at trial to analyze the rebuttal issue, we cannot say that the district court's admissibility rulings fell outside the ‘range of choice’ rising to the level of ‘a clear error of judgment.’”

The panel thus affirms not only the substantive ruling but the methodology: targeted use of proffer statements tied to specific factual assertions by the defense, evaluated statement-by-statement.

D. Precedents Cited and Their Influence

The opinion is built around and consistent with a network of Eleventh Circuit and other-circuit precedents:

1. United States v. Blanco, 102 F.4th 1153 (11th Cir. 2024)

Blanco confirmed that:

  • proffer agreements are construed under contract principles,
  • those principles are adapted to criminal law,
  • hyper-technical and rigidly literal interpretations are disfavored, and
  • ambiguities are resolved in favor of the defendant.

Bonner relies on Blanco and Pielago to claim that a protective reading should bar broad use of his proffer statements. The Eleventh Circuit responds by applying the same principles but concludes that:

  • the waiver clause is not ambiguous; and
  • its reasonable reading, against the background of negotiations and purpose, plainly allows rebuttal use of specific conflicting statements once the defense introduces an inconsistent factual theory.

2. United States v. Pielago, 135 F.3d 703 (11th Cir. 1998)

As discussed above, Pielago is the leading Eleventh Circuit case on harmonizing overlapping clauses in a proffer agreement. It influences Bonner in two ways:

  • Methodologically: read specific reservation/waiver clauses as qualifications of the general non-use promise.
  • Substantively: acknowledge that the government may “use” proffer information in a broader causal sense than direct evidentiary introduction, provided the agreement so allows.

In Bonner, this approach justifies reading the rebuttal clause as a deliberate and enforceable exception to use immunity.

3. United States v. Hill, 643 F.3d 807 (11th Cir. 2011)

Hill is cited for the standard of review—interpretation of a proffer agreement is reviewed de novo. This ensures that the Eleventh Circuit independently checks whether the district court read the waiver clause correctly, rather than deferring under an abuse-of-discretion standard.

4. United States v. Henderson, 409 F.3d 1293 (11th Cir. 2005)

Henderson is cited for the standard that evidentiary rulings admitting a defendant’s proffer statements are reviewed for abuse of discretion. This sets the deferential posture for evaluating the district court’s decision to admit the fourteen statements as rebuttal evidence.

5. United States v. Frazier, 387 F.3d 1244 (11th Cir. 2004) (en banc)

Frazier is a foundational Eleventh Circuit case on abuse-of-discretion review, emphasizing:

  • the range of permissible decisions open to a trial judge, and
  • that appellate courts may affirm even where they “would have gone the other way” if deciding in the first instance.

In Bonner, the court cites Frazier to underscore that:

  • rebuttal determinations are inherently fact- and context-sensitive, and
  • the district court’s well-reasoned, cautious approach falls within that discretionary range.

6. United States v. Gold, 743 F.2d 800 (11th Cir. 1984)

Gold supplies the definition and purpose of rebuttal evidence—“to explain, repel, counteract, or disprove” the adversary’s evidence—and reinforces that decisions about rebuttal lie in the “sound discretion” of the trial judge.

7. United States v. Hall, 653 F.2d 1002 (5th Cir. Unit A 1981), and United States v. Delk, 586 F.2d 513 (5th Cir. 1978)

These former Fifth Circuit cases, which are binding precedent in the Eleventh Circuit for decisions predating October 1, 1981, articulate the “opening the door” principle: a defendant who injects a line of testimony cannot then complain when the prosecution offers rebuttal. Bonner is a straightforward application of that doctrine in the specific setting of a proffer waiver.

8. United States v. Barrow, 400 F.3d 109 (2d Cir. 2005)

Barrow provides the critical distinction between:

  • cross-examination that merely attacks the reliability or credibility of government witnesses (which generally does not trigger a waiver), and
  • cross-examination that implicitly asserts a competing factual narrative (which can trigger a waiver).

The Eleventh Circuit quotes Barrow in emphasising that:

“a defendant's theory presented in his opening statement and the implicit factual assertions elicited during cross-examination that reinforced that statement triggered his proffer agreement's waiver provision.”

9. United States v. Tejada, 956 F.2d 1256 (2d Cir. 1992)

Tejada is cited indirectly (through Barrow) to support the notion that district judges, having watched the entire trial unfold, are in the best position to judge what truly counts as rebuttal.

10. United States v. Scott, 70 F.4th 846 (5th Cir. 2023)

Scott is particularly influential on the question of whether an opening statement alone can trigger a proffer waiver. The Fifth Circuit affirmed admission of proffer statements where the defense, in opening, advanced a “new factual theory” inconsistent with the proffer. The Eleventh Circuit follows this logic, holding that to treat opening statements and cross as categorically safe from triggering waivers would, as Scott warned, allow defendants to “gut the waiver exceptions … with verbal tricks.”

11. Rasbury v. IRS, 24 F.3d 159 (11th Cir. 1994)

Cited by Frazier, Rasbury is used for the “range of choice” formulation of abuse of discretion. It reinforces the highly deferential review applied to trial-level evidentiary judgments like the one at issue here.

E. Key Legal Principles Clarified or Reinforced

Several practical and doctrinal points emerge clearly from Bonner:

  1. Proffer agreements are contracts with a criminal-law overlay.
    Courts will:
    • apply general contract interpretation principles,
    • avoid hyper-technical or rigidly literal constructions, and
    • resolve genuine ambiguities in favor of the defendant.
    But courts will also enforce clearly drafted waiver provisions, especially where the defendant is represented by counsel during negotiations and proffer sessions.
  2. Explicit waiver clauses are enforceable if properly triggered.
    A clause permitting the government to use proffer statements “to rebut any evidence or argument offered by [the defendant] or on his behalf” is:
    • valid and enforceable, and
    • not limited to the defendant’s own testimony; it applies to his counsel’s arguments and the evidence they elicit.
  3. Opening statements and cross-examination can trigger waiver.
    The defense cannot assume that the waiver is triggered only if the defendant testifies. As Bonner holds:
    • Opening statements that present an alternative factual theory conflicting with the proffer can trigger waiver.
    • Cross-examination that implicitly asserts such a factual theory—by eliciting favorable substantive facts—can likewise trigger the waiver.
    Mere attacks on witness credibility or on the sufficiency of proof, without asserting a conflicting factual narrative, may not suffice. But once a coherent alternative story is presented, the waiver applies.
  4. The government’s use of proffer statements must be tailored to rebuttal.
    Even when the waiver is triggered, the prosecution is:
    • limited to those proffer statements—or parts of statements—that directly rebut the defense theory or evidence; and
    • not free to introduce the entirety of the proffer as if it were part of its case-in-chief.
    This “surgical” approach is both required by the contract language (“statements or information” used “to rebut”) and, as Bonner demonstrates, enforced by district judges subject to appellate review.
  5. Rebuttal decisions are highly discretionary.
    Because the distinction between “pure credibility attack” and “implicit factual assertion” is often subtle, the appellate court affords broad discretion to the trial judge, who observed the tone, sequence, and context of the arguments and testimony.

F. Potential Impact and Practical Implications

1. For defense counsel

Bonner carries serious practical warnings for defense lawyers whose clients have given proffer statements subject to waiver clauses:

  • Beware of “storytelling” in opening.
    If the client has made incriminating admissions in a proffer, and the agreement has a rebuttal waiver clause like Bonner’s, counsel must assume that:
    • offering a competing factual narrative in opening—especially as to knowledge, intent, or participation—risks triggering the waiver; and
    • the prosecution will then be able to put damaging admissions before the jury.
  • Be cautious in cross-examination.
    There is a difference between:
    • probing a witness’s memory or bias (e.g., “You were using drugs when you saw this, weren’t you?”), and
    • eliciting facts that affirmatively support a new factual theory inconsistent with the proffer (e.g., “You told my client you had permission, didn’t you?” when the client previously admitted he knew the items were stolen).
    The latter can—and in Bonner, did—open the door to rebuttal use of the proffer.
  • Consider pre-trial clarity and rulings.
    Although the district court here declined to rule definitively on waiver in limine and chose to wait to see how trial unfolded, defense counsel can:
    • seek detailed pre-trial guidance on what lines of defense argument are likely to trigger waiver; and
    • press for clear record of the court’s rationale if waiver is found triggered midtrial.
  • Weigh the strategic value of the proffer itself.
    Knowing that such robust waiver provisions may be enforced, defense counsel must carefully weigh:
    • the benefits of proffering (e.g., potential cooperation credit, influence on charging decisions) against
    • the downside risk that, if negotiations fail and the case goes to trial, the proffer can be used in rebuttal if the defense narrative deviates.

2. For prosecutors

The opinion also offers guidance for the government:

  • Draft clear waiver language.
    The Bonner waiver language—allowing use “to rebut any evidence or argument offered by [the defendant] or on his behalf”—proved enforceable and was interpreted in line with other federal circuits. Prosecutors can take this as a model clause.
  • Use proffer statements surgically, not wholesale.
    Bonner reinforces that courts expect a statement-by-statement justification:
    • tie each proffer statement to a specific defense argument or piece of evidence, and
    • expect courts to exclude proffer statements that are merely cumulative or go beyond rebuttal.
  • Build a clear record on what “opened the door.”
    The government in Bonner carefully documented:
    • the defense’s opening themes, and
    • the specific cross-examination questions and answers that advanced the alternative factual theory.
    That record significantly strengthened its position on appeal.

3. For district courts

District judges receive implicit guidance on best practices:

  • Defer final waiver rulings until the trial record develops.
    The district court declined to rule abstractly at the motion-in-limine stage and instead:
    • waited to see how the defense actually proceeded, and
    • only then determined whether and how the waiver was triggered.
  • Conduct a statement-by-statement analysis.
    Requiring the prosecution to justify each individual proffer statement as rebuttal:
    • enforces the contractual limit that use be for “rebuttal,” and
    • strengthens the evidentiary record against potential appellate claims of overreach.

IV. Simplifying Complex Concepts and Terminology

Several technical legal concepts appear in the opinion. The following explanations may aid general understanding:

1. Proffer Session and Proffer Agreement

  • Proffer session: A meeting between a suspect/defendant (usually with counsel), prosecutors, and agents where the suspect describes his conduct and knowledge of relevant events. It is a hybrid between a debriefing and negotiation session.
  • Proffer agreement: The written contract governing that session, specifying:
    • what use, if any, may be made of the suspect’s statements, and
    • under what conditions the government may use the statements directly (e.g., for rebuttal, impeachment, or upon breach of the agreement).

2. Use Immunity and Limited Immunity

  • Use immunity: A promise that the government will not use a person’s statements directly against them in a criminal case. It can be statutory (compulsion-based) or contractual (as in a proffer agreement).
  • Limited use immunity: A narrower form in which the government promises no direct use, but reserves specified exceptions—such as use for impeachment if the person later testifies inconsistently or for rebuttal of defense evidence.

3. Waiver Provision

A waiver provision in a proffer agreement is a clause in which the defendant agrees that if he later engages in certain conduct (for example, gives inconsistent testimony, or argues a story incompatible with the proffer), he “waives” some of the protection previously granted, allowing the government to use his proffer statements for certain purposes.

4. Rebuttal Evidence vs. Case-in-Chief

  • Case-in-chief: The evidence a party presents in the main part of its presentation, intended affirmatively to prove the elements of the claim or charge.
  • Rebuttal evidence: Evidence introduced after the opponent’s case-in-chief (or sometimes after the defense raises specific evidence) to directly counter, disprove, or explain away points raised by the opponent.

In Bonner, the government’s proffer statements were admitted as rebuttal, not as part of the original prosecution case-in-chief. That distinction matters for enforcing the contractual limitations and for appellate review.

5. “Opening the Door”

To “open the door” is a metaphor: by introducing certain evidence or arguments, a party “opens the door” to the opposing side introducing other evidence that would otherwise have been inadmissible. The idea is one of fairness and completeness: a party cannot selectively present a distorted picture and then complain when the opponent offers context or contradiction.

In the context of proffer agreements, “opening the door” often means that:

  • by presenting a factual theory inconsistent with the proffer, the defense activates the waiver clause, allowing the government to use proffer statements to correct or rebut that theory.

6. Abuse of Discretion

A decision is an “abuse of discretion” if the trial court:

  • applies the wrong legal standard, or
  • makes a decision that is outside the range of reasonable choices, such that it constitutes a clear error of judgment.

On appeal, this is a highly deferential standard; the reviewing court does not simply substitute its judgment for that of the trial court.

7. De Novo (Plenary) Review

De novo review means the appellate court examines the issue “from scratch,” without deference to the trial court’s conclusion. In Bonner, the interpretation of the written proffer agreement—what the words in the waiver clause mean—is reviewed de novo.

V. Critical Observations and Limitations

While Bonner is consistent with existing precedent and doctrinally careful, a few aspects merit closer attention:

  • Non-precedential status.
    The opinion is explicitly marked “Not for Publication.” In the Eleventh Circuit, that typically means it is not binding precedent, though it may be cited as persuasive authority under certain rules. Nonetheless, it offers a clear window into how the court is likely to handle similar waiver clauses in future published opinions.
  • The line between rebuttal and case-in-chief use.
    The government, in closing, told the jury:
    “[a]ll of these admissions by themselves would be sufficient to show that Mr. Bonner knew the unlawful purpose of the plan and willfully joined in it.”
    This underscores how powerful the rebuttal use of proffer statements can be: although admitted as rebuttal, they effectively supplied core evidence of guilt. While contractually authorized, this highlights the stakes: a defendant’s prior attempt at cooperation can become key trial evidence if defense strategy triggers the waiver.
  • Ambiguity versus clear drafting.
    The Eleventh Circuit emphasizes that ambiguities must be resolved in the defendant’s favor. Here, however, it sees the waiver clause as unambiguous. In future cases, disputes may arise where the waiver language is less clear, or its application to subtle forms of argument is more debatable. In such cases, the defendant-friendly canon may play a larger role.
  • Fairness and chilling effect on proffers.
    Decisions like Bonner and Scott might make defendants and defense counsel more wary of proffering at all, particularly where waiver clauses are broad. While the law enforces these waivers when knowingly and voluntarily agreed to, there is an ongoing policy tension between:
    • encouraging candid cooperation (which requires some confidence that statements won’t be used too readily), and
    • preventing defendants from taking “one story” in the proffer room and an incompatible “second story” in front of the jury.
  • Internal inconsistency in the opinion’s naming.
    The opinion refers at the outset to “Steve Bonner” but later states “A federal jury found Scott Bonner guilty….” This appears to be a clerical inconsistency, but it does not affect the substantive analysis.

VI. Conclusion

United States v. Steve Bonner is a detailed and instructive application of proffer-agreement law in the Eleventh Circuit. It confirms and clarifies several important principles:

  • Proffer agreements are governed by contract-law principles, tempered by criminal-law concerns and resolved in the defendant’s favor where ambiguous.
  • Express waiver clauses allowing rebuttal use of proffer statements are enforceable and not confined to situations where the defendant testifies.
  • A defendant “opens the door” under such a waiver not only through direct testimony but also by:
    • advancing a conflicting factual narrative in opening statement, and
    • eliciting testimony in cross-examination that implicitly asserts facts contrary to the proffer.
  • Once the waiver is triggered, the government may introduce only those specific proffer statements necessary to rebut the defense’s evidence or argument; wholesale use remains impermissible.
  • District courts are afforded broad discretion in determining whether and how the waiver has been triggered and which statements truly operate as rebuttal.

For practitioners, Bonner stands as a cautionary tale: a defendant who has proffered cannot safely “pivot” at trial to a contrary story without risking that the proffer itself will be weaponized in rebuttal. The decision underscores the need for meticulous pretrial planning and a precise understanding of what the client has already said under the protection—but also the conditional waiver—of a proffer agreement.

In the broader legal context, Bonner aligns the Eleventh Circuit’s approach with that of the Second and Fifth Circuits, collectively building a robust, cross-circuit framework for enforcing proffer waivers against inconsistent trial strategies while still insisting that such use be narrowly tailored to genuine rebuttal.

Case Details

Year: 2025
Court: Court of Appeals for the Eleventh Circuit

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