One Word in a Jury Instruction: Missouri Appeals Court Reverses Murder Conviction Over Castle Doctrine Self-Defense

On September 15, 2026, the Missouri Court of Appeals, Western District, reversed a Jackson County second-degree murder conviction because the jury instruction joined two self-defense theories with the word “or” instead of “and.” The decision is a close look at how Missouri’s castle doctrine works in a courtroom, and why the wording of a jury instruction can decide a case.

Missouri’s self-defense statute, section 563.031 RSMo, gives people two distinct routes to justify the use of deadly force. One is the general rule that applies anywhere. The other, commonly called the castle doctrine, applies when someone unlawfully enters, or tries to enter, a home, residence or vehicle that the defender lawfully occupies.

In State v. Matlock, the trial court instructed the jury on both routes. The Western District held that when a jury is given both, the State must disprove both beyond a reasonable doubt before it can obtain a conviction. Because the murder instruction told jurors they could convict if the State disproved either one, the court concluded the State’s burden of proof had been lowered, and it ordered a new trial.

What happened

According to the opinion, the defendant and the man who died were co-renters of a house. Each had signed a separate lease, each had his own locked bedroom, and they shared the common areas. On June 16, 2021, after an argument about the cleanliness of the house, the defendant shot the other man in the hallway outside the defendant’s bedroom; the medical examiner found seven gunshot wounds. He called police himself and told officers that the other man had been reaching behind his back and that he believed the man had a weapon. No weapon was found on the other man.

At trial, the defendant testified that the other man blocked him from closing his bedroom door, that part of the man’s arm came into the bedroom, and that the man then appeared to reach for something behind his back. On cross-examination he acknowledged he never saw anything in the man’s hand. The State argued that the defendant was the initial aggressor and that the other man never unlawfully entered any part of the house. The defense argued that the defendant acted out of fear for his life and that the castle doctrine applied because part of the other man’s body crossed into the defendant’s bedroom.

The trial court gave the jury two defense instructions: Instruction No. 5 on general self-defense, patterned on MAI-CR 4th 406.06, and Instruction No. 6 on self-defense under the castle doctrine, patterned on MAI-CR 4th 406.10. The State’s verdict director for second-degree murder then listed, as its third and fourth paragraphs, that the defendant “did not act in lawful self-defense as submitted in Instruction No. 5, or” that he “did not act in lawful self-defense as submitted in Instruction No. 6.” Defense counsel stated no objection. The jury convicted on second-degree murder and armed criminal action, and the court imposed consecutive sentences of eighteen and seven years.

What the Western District held

Because the defense never objected to the instruction and did not raise it in the motion for new trial, the appeal was reviewed only for plain error. That is a demanding standard: the defendant had to show that the instruction was clearly and obviously wrong and that the error caused a manifest injustice. The court noted that saying “no objection” to a State-proposed instruction does not waive plain error review, citing the Supreme Court of Missouri’s decision in State v. Clay.

On the first question, the panel explained that self-defense in Missouri is a special negative defense. The defendant carries only the burden of injecting the issue, which the statute says expressly in subsection 5. Once the issue is injected, the State must prove beyond a reasonable doubt that the defendant did not act in self-defense. The Notes on Use for both pattern instructions require a separate cross-reference paragraph in the verdict director for each self-defense theory, but they do not say whether those paragraphs should be joined by “and” or “or.” The court resolved that gap: because the trial court found enough evidence to submit both theories, the State had to disprove both, and the instruction should have said “and.”

On the second question, the court relied heavily on its own 2002 decision in State v. White, which reversed a second-degree murder conviction where a verdict director used “or” between paragraphs that each had to be proven. The State argued that the instruction’s closing language, which told jurors to acquit unless they found “each and all of these propositions,” cured any confusion. The panel rejected that argument, as it had in White, reasoning that jurors were unlikely to disregard the express word “or.”

The State also pointed to cases in which a missing “and” between instruction paragraphs was held harmless. The court distinguished those decisions. Leaving out a connecting word, it said, does not mislead a literate juror the way that affirmatively substituting “or” for “and” does.

Why the castle doctrine made the error matter

The distinction between the two theories was the heart of the decision. Under the general rule in section 563.031.2(1), deadly force is justified only when a person reasonably believes it is necessary to protect against death, serious physical injury or a forcible felony. Under the castle doctrine in section 563.031.2(2), deadly force may be used against a person who “unlawfully enters, remains after unlawfully entering, or attempts to unlawfully enter a dwelling, residence, or vehicle lawfully occupied by such person.”

Quoting the Supreme Court of Missouri’s 2022 decision in State v. Straughter, the panel observed that the castle doctrine “allows for the use of deadly force in much broader circumstances” than general self-defense. A defender relying on it does not need to face death or serious physical injury; he needs only to reasonably believe force is necessary to defend against the use or imminent use of unlawful force, provided the other statutory conditions are met. Subsection 5 of the statute places the burden on the State to disprove that belief beyond a reasonable doubt once the castle doctrine is asserted.

Because the jury could have rejected general self-defense while still finding the castle doctrine applied, an instruction that allowed conviction on disproof of either theory relieved the State of part of its burden on the central contested issue at trial. The panel found a reasonable probability that the error affected the outcome, reversed both the murder conviction and the dependent armed criminal action conviction, and remanded for a new trial. It added that retrial after reversal for trial error does not violate double jeopardy.

What the decision does not decide

The opinion is about jury instructions, not about whether the shooting was justified. The panel did not rule on whether a co-tenant standing in a shared hallway, whose arm, according to the defendant’s testimony, briefly crossed into another tenant’s bedroom, “unlawfully” entered a dwelling within the meaning of section 563.031.2(2). The State argued there was no unlawful entry; the defense argued there was. The court also did not rule on the State’s initial-aggressor argument, which matters because subsection 1 of the statute generally withholds the justification from a person who was the initial aggressor. Those are factual questions for the jury on retrial, and the evidence the State described, including a cell phone recording and the absence of any weapon in the other man’s hands, will be weighed again.

Practical points for Missouri readers

For anyone facing a charge involving self-defense

The Matlock appeal succeeded under plain error review, which is the narrowest path available. The simpler route is to object at the instruction conference, submit a correct alternative instruction, and repeat the objection in the motion for new trial. Anyone charged with a felony or a firearms offense in which justification is at issue should expect the precise wording of each instruction to receive careful attention.

For gun owners who share a home

The castle doctrine turns on an unlawful entry into a place the defender lawfully occupies. Roommates, co-tenants and family members usually have a lawful right to be in shared spaces, which can make the doctrine far harder to apply inside a shared residence than against an outside intruder. Responsible owners who live with others should understand that the broader castle doctrine standard may not be available to them in every room of their own home.

For landlords renting by the room

The facts of Matlock involved a single house rented to two people under separate leases. For landlords who rent this way, written leases that clearly define private and common areas, and clear procedures for resolving disputes between tenants, can reduce conflict and create a better record if a disagreement escalates. The firm’s landlord-tenant practice regularly addresses how those terms are drafted.

More broadly, the case illustrates a principle that runs through Missouri criminal law: the State bears the burden of disproving a properly injected defense, and a single word in an instruction can shift that burden. Whether one views the outcome as a correct application of due process or as an unwelcome retrial of a serious case, the opinion gives trial judges and lawyers clear direction on how to connect multiple self-defense instructions going forward.

This article is for general educational purposes only and is not legal or tax advice. Reading it does not create an attorney-client relationship with Haake Law Group PC or Derek R. Haake. Laws and court decisions change, and the use of force carries serious criminal and civil consequences. Verify current law with the official sources cited above and consult an attorney about your specific situation.