Denial of a Defense-of-Others Jury Instruction Is Reviewed Under AEDPA § 2254(d)(1), and Keahey Forecloses Habeas Relief Absent Clearly Established Supreme Court Law Requiring the Instruction

Introduction

In Barbara Mercer v. Anthony Stewart (Sixth Cir. Apr. 2, 2026), the Sixth Circuit addressed the recurring habeas question whether a state court’s refusal to give a justification-related jury instruction (here, defense of others) can support federal habeas relief under the Antiterrorism and Effective Death Penalty Act (AEDPA), 28 U.S.C. § 2254.

Parties. Petitioner Barbara Jean Mercer sought federal habeas relief from Michigan convictions for second-degree murder (two counts), tampering with evidence, and third-degree arson. Respondent was the warden, Anthony Stewart.

Factual backdrop. Two drug dealers, Anthony Hannah and Shemel Thomas, were killed and later found in a burned car. The prosecution tried Mercer as an aider-and-abettor (and alleged conspiracy). Co-defendant Richard “Ricky” Janish admitted shooting both victims, later claiming (as to Thomas) he acted to protect Mercer from sexual assault.

Key issues on habeas. Mercer argued (1) a due process violation from the trial court’s refusal to instruct the jury on defense of others regarding Thomas’s killing; (2) ineffective assistance for counsel’s mistaken invocation of duress; and (3) prosecutorial misconduct based on a rebuttal closing misstatement about hearsay and credibility. The district court granted habeas relief on the jury-instruction claim but denied relief on the rest. The Sixth Circuit reversed the grant and affirmed the denials.

Summary of the Opinion

  • Jury-instruction claim (defense of others): The Sixth Circuit held AEDPA barred relief because the question whether the evidence warranted the instruction is a mixed question governed by § 2254(d)(1), not § 2254(d)(2). Under Keahey v. Marquis, there is no clearly established Supreme Court rule requiring a self-defense instruction, and that logic forecloses a defense-of-others instruction claim as well.
  • Ineffective assistance: The court held Mercer could not satisfy Strickland prejudice under AEDPA’s “doubly deferential” review; counsel’s early duress mistake did not reasonably undermine the verdict, especially given the shared mistake by the court and prosecutor and curative instruction.
  • Prosecutorial misconduct: Although the prosecutor misstated hearsay principles, the state court’s conclusion that the trial was not rendered fundamentally unfair was not an unreasonable application of Supreme Court precedent.

Analysis

1) Precedents Cited

AEDPA framework and deference

The opinion grounds its analysis in Supreme Court AEDPA deference cases:

  • Burt v. Titlow and Harrington v. Richter: These cases supply the overarching posture—AEDPA is a “formidable barrier,” and relief is available only for error “beyond any possibility for fairminded disagreement.” The Sixth Circuit uses them to emphasize that even a strong claim of state-law error does not equate to an AEDPA-eligible constitutional violation.
  • Bergman v. Howard: Central to classification of the jury-instruction dispute. The Sixth Circuit relies on Bergman for the proposition that “mixed questions” (applying a legal standard to historical facts) are analyzed under § 2254(d)(1), not § 2254(d)(2).
  • Carter v. Bogan and Davis v. Lafler: These reinforce the high bar for § 2254(d)(2) and the presumption of correctness for state factual determinations absent clear and convincing rebuttal.

Mixed questions, jury instructions, and the (d)(1) vs (d)(2) boundary

  • McMullan v. Booker: The Sixth Circuit treats McMullan as directly on point: “whether to provide a jury instruction” based on a record is not scrutinized under § 2254(d)(2). This is the bridge from abstract mixed-question doctrine to the specific “instruction warranted?” determination.
  • Moore v. Mitchell and Barnes v. Elo: Cited (through Bergman) to show long-standing Sixth Circuit practice treating law-application questions as (d)(1).
  • U.S. Bank Nat. Ass'n ex rel. CWCapital Asset Mgmt. LLC v. Vill. at Lakeridge, LLC and Guerrero-Lasprilla v. Barr: These Supreme Court cases are cited in support of categorizing “application” questions as legal/mixed rather than purely factual, reinforcing the Sixth Circuit’s interpretive methodology.
  • Lambert v Blodgett: The district court relied on this Ninth Circuit approach (separating underlying facts from legal conclusions). The Sixth Circuit does not adopt or reject it, but explains that even under that framework the district court erred by treating the state appellate court’s “no evidence” phrasing as a literal factual finding of zero evidence.
  • Brumfield v. Cain and Wofford v. Woods: Used as contrasts—cases where a state court “ignored” record evidence. The Sixth Circuit says Mercer’s is not such a case because the Michigan Court of Appeals discussed the key record material and simply found it insufficient under the governing standard.
  • Klein v. Martin: Quoted for the proposition that state courts need not write detailed opinions addressing all evidence. This bolsters the Sixth Circuit’s insistence that federal habeas cannot impose opinion-writing demands and must give states the “benefit of the doubt.”

“Clearly established Federal law” and the self-defense/defense-of-others instruction problem

  • Keahey v. Marquis: The dispositive authority. The Sixth Circuit treats Keahey as foreclosing § 2254(d)(1) relief because the Supreme Court has never “clearly established” a constitutional right to a self-defense instruction. The panel extends the logic to Mercer’s defense-of-others claim.
  • Dowling v. United States and Gilmore v. Taylor: Dowling supplies the narrow “fundamental fairness” concept; Gilmore is used to reject a broad theory that the right to present a defense necessarily includes a right to have the jury instructed on it, warning that such a theory would nullify limits on habeas review of state-law instructional errors.
  • Estelle v. McGuire: Serves as a backstop: federal habeas does not lie for errors of state law. Even if Michigan’s “some evidence” standard was misapplied, that alone would not create a federal habeas entitlement.

De novo review, Teague, and limits on announcing new rules in habeas

  • Rice v. White: Cited for the proposition that if a petitioner passes through (d)(2), review can become de novo. The Sixth Circuit’s key move is to clarify what de novo does not mean.
  • Teague v. Lane, Edwards v. Vannoy, Horn v. Banks, and Williams v. Taylor: These frame the non-retroactivity principle. The Sixth Circuit stresses that even if AEDPA deference drops out, Teague can still bar relief because habeas courts may not announce and retroactively apply “new rules.”
  • Caspari v. Bohlen: Cited to note the state may waive Teague arguments; the court emphasizes it is not deciding Teague here but flags it as a persistent constraint.

Ineffective assistance standards under AEDPA

  • Strickland v. Washington and Harrington v. Richter: Provide the governing two-prong framework and AEDPA’s overlay—Mercer must show the state court’s no-prejudice conclusion is beyond fairminded disagreement.
  • White v. Plappert: Used to characterize the “doubly deferential gauntlet” for ineffective assistance claims on habeas.
  • English v. Romanowski: Mercer’s preferred analogy (counsel’s credibility harmed by an unfulfilled promise). The Sixth Circuit distinguishes it because, here, the prosecutor and court shared the error and the trial court issued corrective instructions.
  • Delaware v. Van Arsdall and Thompson v. Rapelje: Support the idea that the Constitution guarantees a fair, not perfect trial, and that juries are expected to follow curative instructions.

Prosecutorial misconduct and “fundamental fairness”

  • Parker v. Matthews: Provides the operative due process standard (“so infected the trial with unfairness”) and underscores that the standard is “very general,” granting state courts leeway.
  • Trimble v. Bobby: Reinforces that a petitioner must point to Supreme Court precedent making the state court’s resolution unreasonable in the specific factual context.
  • Darden v. Wainwright and Donnelly v. DeChristoforo: Used comparatively: even more inflammatory comments did not compel relief there, so the state court’s no-relief conclusion here could not be deemed unreasonable.
  • Stewart v. Trierweiler: Cited to describe the severity of the prosecutor’s rhetoric in Darden, strengthening the comparison.

State-law authorities informing (but not controlling) the federal analysis

The opinion recounts Michigan’s “defense of others” framework:

  • People v. Guajardo (reasonableness depends on ordinarily prudent person based on actor’s perceptions)
  • People v. Leffew and People v. Lemons (defendant must produce “some evidence”; burden not heavy; instruction required only if sufficient evidence)
  • People v. Mercer (Michigan Court of Appeals’ decision under review) and People v. Mercer, 863 N.W.2d 329 (Mich. 2015) (mem.) (leave denial)
  • People v. Buckley (credibility arguments as permissible prosecutorial theme)

2) Legal Reasoning

A. The classification move: instruction-warranted determinations are (d)(1) mixed questions

The pivotal analytical step is the panel’s rejection of the district court’s attempt to treat the Michigan Court of Appeals’ conclusion— phrased as “no evidence”—as a factual determination reviewable under § 2254(d)(2). The Sixth Circuit instead characterizes the state court’s work as: (1) accepting the historical record (texts, interviews, circumstances); (2) applying Michigan’s “some/sufficient evidence” standard; and (3) concluding the evidence did not permit the inference required for defense of others (imminence and honest/reasonable belief).

That application is exactly what Bergman v. Howard and McMullan v. Booker place in § 2254(d)(1), because it is not the question “what happened?” but “do these facts satisfy the legal threshold for an instruction?”

B. The merits under (d)(1): Keahey bars relief because there is no clearly established Supreme Court right to the instruction

Once categorized as (d)(1), Mercer needed clearly established Supreme Court law requiring a defense-of-others (or self-defense) instruction. Keahey v. Marquis holds there is no such clearly established rule for self-defense instructions. The panel treats this as dispositive: without a Supreme Court holding recognizing the constitutional right Mercer asserts, the state court decision cannot be “contrary to” or an “unreasonable application of” clearly established law.

The opinion also invokes Gilmore v. Taylor to caution against bootstrapping the general right to present a defense into a specific, instruction-based entitlement on habeas review, because that would convert ordinary state-law instruction questions into federal habeas claims.

C. Correcting a doctrinal misconception: de novo review does not authorize new rules (Teague still applies)

The district court, after finding (d)(2) satisfied, proceeded de novo and recognized a federal right to a defense-of-others instruction by relying on other circuits and states. The Sixth Circuit rebukes the implication that de novo review allows a habeas court to announce and apply new procedural rules; Teague v. Lane and related cases bar retroactive creation of new rules in habeas, and AEDPA’s deference regime is distinct from Teague.

Although the panel declines to decide Teague’s application (noting Caspari v. Bohlen), it uses the discussion to reinforce the boundary: even if AEDPA deference falls away, habeas remains constrained by non-retroactivity doctrine.

D. Ineffective assistance: no Strickland prejudice under AEDPA’s “doubly deferential” lens

Mercer’s ineffective-assistance theory was largely reputational: counsel’s mistaken reference to duress (an unavailable homicide defense under Michigan law) undermined credibility. The Sixth Circuit accepts the mistake but focuses on prejudice:

  • Counsel pursued a continuing, valid strategy—arguing Mercer lacked the mental state for murder/conspiracy and expected only “scaring,” not killing.
  • The duress error was shared by the prosecutor and judge, reducing the likelihood the jury uniquely discounted Mercer’s counsel.
  • The court’s explicit curative instruction directing jurors not to consider duress is presumed effective.

The panel distinguishes English v. Romanowski, where defense counsel made an unfulfilled promise about witness testimony without the same type of judicial/prosecutorial ownership and corrective instruction. Under Strickland v. Washington and Harrington v. Richter, Mercer did not show that the state court’s no-prejudice conclusion was beyond fairminded disagreement.

E. Prosecutorial misconduct: incorrect hearsay commentary did not render the trial fundamentally unfair

The prosecutor inaccurately suggested admissions against interest are “inherently believable” and self-serving statements “inherently unbelievable” and barred by hearsay. The Michigan Court of Appeals called this inappropriate but not outcome-determinative. Applying Parker v. Matthews, the Sixth Circuit emphasizes the generality of the due-process test and the “leeway” afforded state courts. The panel highlights:

  • The remarks were isolated and embedded in a broader credibility argument.
  • Curative instructions informed the jury that lawyer argument is not evidence and that the hearsay rule is complex.
  • Darden v. Wainwright and Donnelly v. DeChristoforo denied relief in arguably worse circumstances, making it hard to call this case an unreasonable application.
  • The jury’s verdict (second-degree rather than first-degree) suggested it did not simply accept the prosecutor’s discrediting theory of defendants’ statements.

3) Impact

  • Reinforces (d)(1) as the primary battleground for instruction-warranted disputes. Petitioners often attempt to recast “insufficient evidence for instruction” rulings as (d)(2) factual unreasonableness; this opinion, building on Bergman v. Howard and McMullan v. Booker, tightens that pathway in the Sixth Circuit.
  • Extends Keahey’s practical effect to defense-of-others claims. Even if a state’s law strongly supports giving defense-of-others/self-defense instructions, habeas relief remains largely unavailable unless the Supreme Court clearly establishes the specific constitutional right to such an instruction.
  • Signals limits on district-court innovation during de novo review. The opinion’s Teague discussion serves as a caution: a habeas court cannot use “de novo” review as a license to craft and apply new procedural rules based on non-Supreme Court authorities.
  • Raises the bar for “credibility collapse” prejudice theories. Where a trial error is shared and corrected (judge/prosecutor acknowledge mistake; court issues curative instructions), claiming counsel became non-credible may be especially hard to translate into AEDPA-eligible Strickland prejudice.

Complex Concepts Simplified

AEDPA § 2254(d)(1) vs § 2254(d)(2)
  • (d)(1) asks whether the state court unreasonably applied clearly established Supreme Court law.
  • (d)(2) asks whether the state court made an unreasonable factual determination based on the state-court record.
This case holds that deciding whether evidence is “enough” to require a jury instruction is typically a mixed law-and-fact application question for (d)(1), not a pure factual question for (d)(2).
“Mixed question”
A question that takes settled historical facts and asks whether they satisfy a legal standard (e.g., whether the facts constitute “some evidence” justifying a defense instruction).
“Clearly established Federal law”
A rule found in an actual holding of the U.S. Supreme Court (not lower courts; not dicta), stated with sufficient specificity. Without such a holding, a habeas petitioner cannot win under (d)(1).
De novo review (in habeas)
Reviewing an issue without AEDPA deference to the state decision. But it does not remove other habeas limits, such as Teague v. Lane’s ban on retroactively applying “new rules.”
Teague “new rule” bar
Federal habeas cannot generally grant relief by announcing a new constitutional procedural rule not dictated by existing precedent at the time the conviction became final.
Strickland “doubly deferential” review
In state convictions reviewed on habeas, courts apply deference both to counsel’s performance choices (Strickland) and to the state court’s adjudication (AEDPA), making relief especially difficult.
Prosecutorial misconduct “fundamental fairness” test
Improper comments violate due process only if they so infect the trial with unfairness that the conviction is a denial of due process—a highly context-dependent, general standard.

Conclusion

The Sixth Circuit’s decision in Mercer v. Stewart establishes (and strongly reinforces) three practical rules for habeas litigation: (1) a state court’s refusal to give a justification-based instruction based on record sufficiency is ordinarily a § 2254(d)(1) mixed question; (2) under Keahey v. Marquis, habeas petitioners generally cannot obtain relief for the absence of self-defense/defense-of-others instructions because the Supreme Court has not clearly established such a right; and (3) even when a federal court reviews de novo, it cannot evade core habeas limits—especially Teague’s prohibition on retroactively applying newly announced procedural rules.