Perjury Under § 1623 Cannot Rest on “I Don’t Know” About Another’s Motives Absent a Foundation

1. Introduction

United States v. Milliron (10th Cir. June 23, 2026) arose from a federal grand-jury investigation into whether dentist Larry Rudolph murdered his wife, Bianca Rudolph, during a 2016 safari in Zambia and then obtained approximately $5 million in life-insurance proceeds. Lori Milliron—Rudolph’s longtime employee and romantic partner—testified before the grand jury under subpoena. Based on that testimony, the government charged Milliron with five counts of perjury (18 U.S.C. § 1623(a)), accessory after the fact to foreign murder (18 U.S.C. §§ 3, 1119, 1111), and obstruction of justice (18 U.S.C. § 1503(a)).

After a joint trial with Rudolph, a petit jury convicted Milliron on two perjury counts (Counts Six and Nine), accessory after the fact, and obstruction. On appeal, Milliron principally argued that (i) the perjury convictions resulted from imprecise questioning and lacked sufficient evidence; (ii) accessory after the fact cannot be based on perjury/false testimony alone; and (iii) punishing her for both perjury and obstruction violated the Double Jeopardy Clause.

The Tenth Circuit vacated Count Six (perjury) as unsupported by sufficient evidence of knowing falsity, but affirmed Count Nine (perjury), accessory after the fact, and obstruction.

2. Summary of the Opinion

  • Perjury (Count Six) vacated: Milliron’s answers “I don’t know” to why Rudolph was “so generous” and “exactly why” he gave her $60,000 in 2015 could not support perjury because the questions asked her to speculate about Rudolph’s motives and the record lacked evidence that she actually knew those motives.
  • Perjury (Count Nine) affirmed: A reasonable jury could find Milliron knowingly lied when, in the context of a specific conversation about the FBI investigation, she testified Rudolph “probably” proclaimed his innocence; the court also held the statement was material under the circuit’s “conspicuously low” materiality standard.
  • Accessory after the fact affirmed: Under binding circuit precedent, false statements intended to hinder apprehension/trial/punishment can qualify as “assist[ing] the offender” under 18 U.S.C. § 3; perjury-like conduct can therefore support accessory liability.
  • Obstruction affirmed; no double jeopardy: Obstruction under § 1503(a) is not a lesser-included offense of perjury under § 1623(a) because obstruction requires a distinct element—specific intent to subvert the due administration of justice.

Judge Carson concurred in part and dissented in part, agreeing on Count Six, accessory, and double jeopardy, but disputing the sufficiency of evidence for Count Nine.

3. Analysis

3.1. Precedents Cited

A. Perjury: precise questioning, speculation, and “knowing falsity”

  • Bronston v. United States, 409 U.S. 352 (1973):
    • Used as the foundational warning that “[p]recise questioning is imperative as a predicate to the offense of perjury”, and that the burden is on the questioner to “pin the witness down.”
    • Milliron extends Bronston’s practical lesson beyond “literally true but evasive” answers to the scenario where the question itself demands speculation about another person’s internal motivations; the court frames this as a prosecution problem (ask better questions), not a perjury solution.
  • United States v. Lighte, 782 F.2d 367 (2d Cir. 1986):
    • Central to Count Six: Lighte held that “I don’t know” cannot be perjury when the question requires speculation about someone else’s motives.
    • The Tenth Circuit adopts Lighte’s logic: absent evidence that the motive was communicated to the witness, the government cannot prove the witness knew the “I don’t know” answer was false.
  • United States v. Leifson, 568 F.3d 1215 (10th Cir. 2009) and United States v. Strohm, 671 F.3d 1173 (10th Cir. 2011):
    • Provide the four elements of 18 U.S.C. § 1623(a) and govern sufficiency review.
    • Strohm is also used to clarify doctrinal boundaries:
      • Literal-truth defense: Strohm limits it to nonresponsive but literally true answers; the panel notes “I don’t know” is typically responsive and thus Count Six is not a literal-truth case.
      • Materiality and multi-statement perjury counts: Strohm supports affirmance of Count Nine even if only one charged statement is proven knowingly false and material.
  • United States v. Farmer, 137 F.3d 1265 (10th Cir. 1998):
    • Used for two linked principles: (i) courts should not “affirm a conviction based on a jury’s guess,” and (ii) questions must be assessed in context rather than isolated from surrounding testimony.
    • Farmer supports the Count Six result (no speculative leaps about motive) and the Count Nine result (context shows the prosecutor asked about a specific conversation, not Rudolph’s general public posture).
  • United States v. Tapaha, 891 F.3d 900 (10th Cir. 2018) and United States v. Hoffner, 777 F.2d 1423 (10th Cir. 1985):
    • Cited to underscore the court’s skepticism toward speculative testimony about a person’s state of mind without foundation—reinforcing why motive-guessing “I don’t know” answers are difficult to convert into “knowing falsity.”
  • United States v. Sainz, 772 F.2d 559 (9th Cir. 1985) and United States v. Shotts, 145 F.3d 1289 (11th Cir. 1998):
    • Serve as persuasive reinforcement of Bronston’s theme: the prosecutor’s role is “to obtain the truth,” not “to obtain perjury,” and the appropriate response to evasiveness is better questioning.

B. Accessory after the fact: false statements as “assistance”

  • United States v. Day, 533 F.2d 524 (10th Cir. 1976):
    • Binding precedent holding that false statements to an investigator about a crime can constitute “assist[ing] the offender” under 18 U.S.C. § 3.
    • Day is the decisive authority rejecting Milliron’s argument that § 3 requires affirmative acts beyond lying.
  • Yates v. United States, 574 U.S. 528 (2015) (plurality opinion):
    • Mentioned to acknowledge a possible canon-of-construction concern (avoid giving one word a breadth inconsistent with its neighbors), but the panel declines to revisit the issue because Day already governs.
  • United States v. Lepanto, 817 F.2d 1463 (10th Cir. 1987):
    • Milliron relied on Lepanto’s skepticism about imposing accessory liability for “every false unsworn statement” to federal officers.
    • The panel treats Lepanto’s caution as dicta and distinguishes it (Milliron lied under oath before a grand jury), while noting Lepanto did not purport to limit Day.
  • United States v. Reed, 39 F.4th 1285 (10th Cir. 2022) and Tokoph v. United States, 774 F.3d 1300 (10th Cir. 2014):
    • Reed supplies the rule of interpanel stare decisis (later panels are bound absent en banc/Supreme Court change).
    • Tokoph supplies the rule that dicta is not binding, used to discount Lepanto’s broad language.
  • Additional authorities used to support the breadth of § 3 as applied: United States v. Roach, 502 F.3d 425 (6th Cir. 2007); McFarland v. Childers, 212 F.3d 1178 (10th Cir. 2000); United States v. Osborn, 120 F.3d 59 (7th Cir. 1997); Ortega v. Evans, No. 08-CV-00894, 2009 WL 1085483 (E.D. Cal. Apr. 22, 2009).

C. Double jeopardy / multiplicity: perjury vs. obstruction

  • Blockburger v. United States, 284 U.S. 299 (1932):
    • Governs whether one offense is a lesser-included offense of another by comparing statutory elements.
  • United States v. Isabella, 918 F.3d 816 (10th Cir. 2019); United States v. Angilau, 717 F.3d 781 (10th Cir. 2013); United States v. Dixon, 509 U.S. 688 (1993):
    • Reiterate that Blockburger compares elements, not the overlapping conduct charged in an indictment.
  • United States v. Benoit, 713 F.3d 1 (10th Cir. 2013) and United States v. Morris, 247 F.3d 1080 (10th Cir. 2001):
    • Clarify that multiplicitous convictions can exist, but imposing separate sentences for multiplicitous offenses violates double jeopardy.
  • United States v. Erickson, 561 F.3d 1150 (10th Cir. 2009) and 10th Cir. Crim. Pattern Jury Instruction 2.62:
    • Provide the elements of obstruction under 18 U.S.C. § 1503(a), particularly the specific intent to subvert the due administration of justice.
  • Persuasive consensus from other circuits that obstruction is not a lesser-included offense of perjury: United States v. Langella, 776 F.2d 1078 (2d Cir. 1985); United States v. Rankin, 870 F.2d 109 (3d Cir. 1989); United States v. Bridges, 717 F.2d 1444 (D.C. Cir. 1983); United States v. Hill, 442 F. App’x 811 (4th Cir. 2011); plus the intent distinction discussed in United States v. Williams, 874 F.2d 968 (5th Cir. 1989) and United States v. Grubb, 11 F.3d 426 (4th Cir. 1993).

3.2. Legal Reasoning

A. Count Six: why “I don’t know” about motive was not “knowingly false”

The court’s key move is to treat the prosecutor’s questions—“Why was Larry so generous to you?” and “you don’t know exactly why he gave you $60,000 in 2015?”—as requests for testimony about Rudolph’s internal motivations. Under § 1623(a), the government had to prove Milliron’s answers were (i) false and (ii) that she knew they were false.

The panel held that, without evidence Rudolph told Milliron his reasons for the 2015–2016 generosity (or otherwise supplied a concrete basis for her knowledge), the government could not establish “knowing falsity.” The court refused to let the jury “guess” a single “exact” reason (e.g., “because they were in a relationship”) as though it were the only plausible motive, emphasizing that multiple motives could coexist.

Notably, the panel clarified what Count Six is not: it is not a “literal truth” reversal (because “I don’t know” is responsive under United States v. Strohm), and it is not a “fundamental ambiguity” case (the questions were understandable, but demanded speculation). It is a sufficiency-of-the-evidence holding grounded in the mismatch between the knowledge element and the government’s failure to prove a foundation for knowledge of motive.

B. Count Nine: contextual narrowing of the question and inference of knowing falsity

For Count Nine, the court treated the prosecutor’s “Did he proclaim his innocence?” as tied—by surrounding questions—to a specific conversation about the FBI investigation (not Rudolph’s general habit of proclaiming innocence to the world). Applying United States v. Farmer, the panel insisted questions cannot be read in isolation; context can narrow meaning.

On that narrowed meaning, the panel found sufficient evidence for a reasonable jury to infer Milliron knew Rudolph did not proclaim his innocence to her in that conversation, relying heavily on relationship-specific evidence: Milliron’s long intimacy with Rudolph, her proximity to key events, and especially Rudolph’s earlier steakhouse statement, “I killed my fucking wife for you.” The court deemed it reasonable to infer that Rudolph would not “proclaim innocence” to the one person he had (in effect) confessed to and bound by shared benefit.

Judge Carson’s dissent highlighted the tension with Bronston v. United States and argued the government failed to ask with “near-absolute clarity” about the specific conversation; he also pointed to abundant record evidence of Rudolph proclaiming innocence generally. The majority’s answer, in essence, is that Count Nine turned not on whether Rudolph ever proclaimed innocence, but whether he did so in the particular FBI-investigation conversation as framed by the examination’s context.

C. Materiality: reaffirming the “conspicuously low” threshold

The panel reaffirmed that materiality under § 1623 is “conspicuously low” and asks only whether the statement was capable of influencing the grand jury, not whether it actually did or whether there was ample other evidence. Here, whether Rudolph “proclaimed innocence” to his most intimate confidante could influence the grand jury’s view of intent, consciousness of guilt, and credibility of the “accident” narrative.

D. Accessory after the fact: perjury-like assistance remains within § 3 (in the Tenth Circuit)

Milliron’s textual argument—that “receives, relieves, comforts or assists” suggests affirmative conduct beyond testimony—ran into United States v. Day. The panel treated Day as binding on the proposition that lying to hinder apprehension/trial/punishment can itself constitute “assist[ing]” under § 3. The court also declined to use United States v. Lepanto to narrow Day, emphasizing Lepanto’s remarks were dicta and involved “false unsworn statements,” whereas Milliron lied under oath with extensive procedural safeguards.

The decision thus solidifies (and may encourage) a charging pathway in this circuit: when false statements are given with the purpose of shielding a principal offender, § 3 can attach even if the “assistance” is informational rather than physical.

E. Double jeopardy: perjury and obstruction require different intents

The court rejected Milliron’s claim that obstruction is a lesser-included offense of perjury. Under Blockburger v. United States, obstruction contains a distinct element: specific intent to subvert or undermine the due administration of justice. Perjury requires knowing falsity and materiality, but does not require an intent to obstruct. Overlap in conduct (lying can obstruct) does not collapse the element-based test.

3.3. Impact

A. Grand-jury practice: a sharper boundary on “motive questions” in perjury prosecutions

Milliron’s most concrete doctrinal contribution is its sufficiency-based rule of restraint: where prosecutors ask a witness to explain why someone else acted— especially with qualifiers like “exactly why”—a perjury case cannot be sustained on an “I don’t know” answer absent evidence the witness had a reliable foundation for knowing that motive (for example, the actor told the witness, or the witness otherwise acquired that information).

Practically, the case encourages prosecutors to replace motive-guessing questions with foundation-building questions: who said what, when, what was promised, what was understood, what did you believe, what did you agree to—i.e., questions anchored in the witness’s own perceptions and communications rather than inferences about another’s internal state.

B. Perjury charging decisions: “imprecise” vs. “ambiguous” vs. “speculative”

The opinion draws a useful taxonomy:

  • Ambiguous question defenses (fundamental/arguable ambiguity) apply when reasonable people cannot tell what is being asked.
  • Literal-truth defense applies when the answer is literally true but nonresponsive.
  • Speculation problem (Milliron): even clear questions can be impermissibly speculative; without proof the witness has a foundation for knowing, “I don’t know” is not “knowingly false.”

C. Expansion pressure on § 3 (accessory) remains—tempered by intent

By reaffirming United States v. Day, the court leaves in place the possibility that perjury-like conduct can drive accessory-after-the-fact liability—raising (as the panel acknowledged) potential overcharging concerns. The limiting principle, however, remains statutory: the government must prove the defendant acted “in order to hinder or prevent” apprehension, trial, or punishment. Not every lie under oath will satisfy that accessory-specific intent.

D. Cumulative punishment: perjury and obstruction can both stand

The ruling adds to a growing cross-circuit consensus that prosecutors may charge and obtain separate punishments for perjury and obstruction where the obstruction-specific intent is proven. Defense strategies based on “lesser-included” arguments will face an element-based barrier.

4. Complex Concepts Simplified

  • Perjury under 18 U.S.C. § 1623(a): Lying under oath in a grand jury or court proceeding. The government must prove (1) oath, (2) falsity, (3) knowledge of falsity, and (4) materiality.
  • “Knowingly false”: It is not enough that a statement was wrong; the witness must have known it was wrong when said.
  • Materiality (low threshold): The lie only needs to be capable of influencing the proceeding; it need not actually change the outcome.
  • Literal-truth defense: A witness cannot be convicted for an answer that is literally true even if it misleads, so long as the government’s remedy was to ask a better follow-up question.
  • Ambiguity defenses: If the question is so unclear that a truthful answer cannot be pinned down, perjury cannot rest on the response.
  • Accessory after the fact (18 U.S.C. § 3): Helping someone who committed a federal offense, knowing they did it, with the purpose of hindering their apprehension, trial, or punishment. In the Tenth Circuit, “help” can include lies that obstruct investigators or proceedings.
  • Multiplicity / Double Jeopardy: The Constitution forbids multiple punishments for the same offense. Under Blockburger, courts compare the statutory elements; if each crime has an element the other lacks, separate punishments may be imposed even if the same conduct is involved.
  • Dicta: Statements in an opinion not necessary to the result; they are not binding precedent.

5. Conclusion

United States v. Milliron delivers a dual message about truth-seeking in grand-jury practice. First, it enforces a meaningful evidentiary constraint on perjury prosecutions: where the government’s questioning calls for speculation about another person’s motives, an “I don’t know” answer cannot be treated as perjury absent proof the witness had a concrete foundation to know the motive. Second, it simultaneously affirms robust prosecutorial tools where the evidence supports them: perjury can be sustained when context narrows the question and the record supports knowing falsity and materiality; accessory-after-the-fact liability can attach to false statements intended to shield an offender; and obstruction is not a lesser-included offense of perjury under an element-based double-jeopardy analysis.

The case’s lasting significance is its insistence—echoing Bronston v. United States—that the justice system should respond to imprecise examinations with sharper questions, not reflexive perjury charges, while preserving perjury’s core function where a witness knowingly lies about concrete, provable facts.