Suppose two people are charged with murder for one killing. Only one of them pulled the trigger. The other is charged as an accomplice, meaning the Commonwealth says she helped plan or carry out the killing. At trial, the accomplice testifies that the shooter fired only to stop an attack on her. Can she ask the jury to decide whether the shooting was justified, even though she did not fire the gun?
In Commonwealth v. Parks, 2026 PA Super 252 (filed November 6, 2026), the Superior Court answered that question for the first time in Pennsylvania. The answer is yes. The court also restated a rule that matters in every homicide trial where self-defense comes up: if there is any evidence supporting the defense, the judge must give the instruction, and the judge cannot refuse it because the defendant’s story seems hard to believe.
When a Self-Defense Instruction Must Be Given
Self-defense and defense of others are “justification” defenses, found in Sections 505 and 506 of the Crimes Code. They do not deny that force was used. They say the force was lawful. If the jury finds the force was justified, no crime was committed.
Once the defense is properly in the case, the defendant does not have to prove it. The Commonwealth has to disprove it beyond a reasonable doubt, by proving that at least one of three elements is missing: (1) the person who used force, or the person he was protecting, was free from fault in provoking or continuing the fight; (2) he reasonably believed that he or the other person faced death or serious injury and that deadly force was necessary; and (3) neither of them violated a duty to retreat.
Whether the jury hears about the defense at all is a question for the judge, but the threshold is low. The claim goes to the jury if there is “any evidence from whatever source” supporting the three elements. Commonwealth v. Hornberger, 74 A.3d 279, 284-85 (Pa. Super. 2013). That evidence can come from the defendant’s testimony, the Commonwealth’s witnesses, or cross-examination.
The credibility point traces to the Superior Court’s en banc decision in Commonwealth v. Mayfield, 585 A.2d 1069, 1071 (Pa. Super. 1991). (An en banc decision is one issued by a larger panel of the court, and it binds later three-judge panels.) Mayfield, restating earlier case law, held that the charge “must be given upon request where the jury would have a possible basis for finding it,” and that this holds “even though the evidence of self-defense may appear to the trial court as not credible.” Judging credibility is the jury’s job. A judge who refuses the instruction because the defendant’s account seems unlikely has taken that job from the jury.
What Happened in Parks
The case comes from Clearfield County. Danielle Parks had separated from her husband after a history of abuse. In 2023 he was charged with strangling her, she obtained a Protection From Abuse order (a civil order barring him from contact with her), and he was twice charged with violating it. During the separation, Parks began a relationship with Bryan Michaelis.
On February 24, 2024, the husband came to the home where Parks was living to pick up their children. That night he was shot five times in an upstairs hallway with a .22 handgun Parks had bought the day before.
Parks’s account changed several times. She first told police that she shot her husband while he was on top of her. In a later interview, she said Michaelis came into the house during the attack, fought with her husband over the gun, and shot him. At trial she gave that second version: her husband charged into the house and tackled her, her gun fell from her waistband, Michaelis came up the stairs, both men grabbed for the gun, and Michaelis shot him.
The Commonwealth’s theory was that Parks and Michaelis planned the killing. Its evidence included a recorded jail call in which Michaelis said he was “coming back for” the husband, the gun purchase about an hour after Parks bailed Michaelis out of jail, burned clothing at a friend’s home, and Parks’s admission that she fired the gun afterward so she would have gunshot residue on her hands. She was tried as an accomplice.
At the charging conference, defense counsel asked for instructions on self-defense and defense of others. The Commonwealth objected that because Parks now said Michaelis was the shooter, any justification defense was “[Michaelis’s] defense to raise, not hers.” The trial court agreed and refused both instructions. The jury convicted Parks of first-degree murder and conspiracy, and she was sentenced to life in prison.
An Accomplice Can Rely on the Shooter’s Justification
Judge Murray wrote for a unanimous panel that included Judges Bowes and Olson. The court found no Pennsylvania case on the question and treated it as one of first impression.
The reasoning rests on how accomplice liability works. An accomplice is not guilty of a separate crime. Accomplice liability under Section 306 of the Crimes Code is only a way of holding one person responsible for a crime someone else committed. Justification, on the other hand, means no crime occurred at all. Commonwealth v. Weston, 749 A.2d 458, 461 (Pa. 2000). Putting the two together, the court held that if the shooter’s conduct was not criminal, the accomplice cannot be held liable for it.
The court noted a conflict in how the case was tried. The trial court acknowledged that Parks was convicted as an accomplice, yet refused the instruction because she “was not the individual who actually shot and killed” her husband. The Commonwealth prosecuted her as an accomplice, yet argued she could not raise justification because she was not the “slayer.” The court observed that the Commonwealth’s brief never mentioned accomplice liability or tried to reconcile it with that position.
The court also pointed out that Sections 505 and 506 speak of an “actor” and never say the actor must be the defendant. It cited two earlier sufficiency cases, Commonwealth v. Johnson, 236 A.3d 1141 (Pa. Super. 2020) (en banc), and Commonwealth v. Laurin, 409 A.2d 1367 (Pa. Super. 1979), in which the court asked whether the Commonwealth had disproved that a co-defendant shooter acted in self-defense. Those cases suggested that a justified shooting would have defeated the non-shooter’s conviction. And it found the same result in State v. Montanez, 894 A.2d 928 (Conn. 2006), along with decisions from Delaware, Georgia, and a federal court in California.
The holding is this: where a defendant is charged as an accomplice and there is evidence that the principal acted in justifiable self-defense or defense of others, the trial court must instruct the jury on those defenses and tell the jury that the Commonwealth must disprove them beyond a reasonable doubt.
The Trial Court Cannot Weigh Credibility
The second half of the opinion applies the Mayfield rule, and it is the part most likely to matter beyond accomplice cases.
The court walked through each element. Parks testified that her husband attacked her in her home without provocation and that she feared he would break her neck, which she had broken twice before. The record showed the strangling charge, the order violations, and evidence that the husband had been “on a rampage” over her relationship with Michaelis. The pathologist placed the gun six to twelve inches from the husband’s body when it was fired, which kept it within reach of a much larger man during the struggle. If believed, that evidence could support a finding that Michaelis reasonably believed deadly force was needed to protect Parks.
There was no duty to retreat. Under Pennsylvania’s “castle doctrine,” a person need not retreat from her own home, and Section 506(b) gives a person defending someone else no greater duty to retreat than the person he is protecting. The jury could also have applied Section 505(b)(2.1), which presumes a reasonable belief that deadly force was necessary when the other person unlawfully and forcefully entered a home.
The trial court had also reasoned that because Parks testified she had gotten free and was moving toward her father’s bedroom when the shots were fired, she could not have believed she was in danger. The Superior Court rejected that. The hallway was small, Parks said a ricochet hit her, and her husband could have blocked the stairs. Most importantly, her account described an immediate danger that he would get the gun while she stood in his line of fire.
The court then acknowledged that the Commonwealth “presented substantial evidence to impair the credibility of Appellant’s account.” That did not change the result. The instruction “must be given upon request, … even though the evidence of self-defense [or defense of others] may appear to the trial court as not credible,” because credibility is the jury’s “sole province.”
Parks gave several versions of what happened, and the Commonwealth had strong evidence of planning. The instruction was still required. The judge asks whether the evidence, if believed, supports each element. Whether to believe it is for the jury.
A New Trial, and Two Issues for the Retrial
The court held that the refusal was an abuse of discretion requiring a new trial. The charge told the jury nothing about justification, including that the Commonwealth had to disprove it. Relying on Commonwealth v. Wortham, 369 A.2d 1287 (Pa. 1977), which granted a new trial over a faulty alibi instruction where alibi was the only defense, the court noted that justification was Parks’s entire defense. The Commonwealth did not argue harmless error.
Two footnotes look ahead to the retrial. Parks preserved only the defense-of-others claim on appeal, but the court said there was also some evidence that Michaelis acted in his own self-defense. And the court noted that the Section 505(b)(2.1) presumption does not apply if the jury finds an exception under Section 505(b)(2.2), including where the person using force “is engaged in criminal activity.”
The opinion also notes that Michaelis was tried separately, his jury received both justification instructions, and it convicted him anyway. His appeal is pending before the same panel. The instruction does not guarantee a different verdict. Parks holds that the jury, not the judge, decides.
Parks raised one other issue. She argued that judicial estoppel, which bars a party from taking a position inconsistent with one it successfully took earlier, should have stopped the Commonwealth from suggesting in closing that her husband never strangled her, since the same office had charged him with it. The court found the issue waived because trial counsel never objected.