When Self-Defense Leads to the Death of a Bystander: The SJC Recognizes Transferred-Intent Self-Defense
Introduction
In a landmark decision issued on October 14, 2025, the Massachusetts Supreme Judicial Court recognized a new and important principle in the law of self-defense: a person who lawfully defends himself against an attacker may, in certain circumstances, be excused from criminal liability if an innocent bystander is killed.
The case, Commonwealth v. Kenneth Jose Santana-Rodriguez (SJC-13753), establishes that self-defense can transfer to an unintended victim—but only to a point. A defendant who acts reasonably in defending himself may be found not guilty of murder, but he may still be convicted of involuntary manslaughter if his use of force was wanton or reckless10-116-25.
This decision fills a gap in Massachusetts law and brings the Commonwealth in line with most other states, which have long recognized some form of transferred-intent self-defense.
Case Background
In January 2023, Kenneth Jose Santana-Rodriguez went to a Holyoke nail salon with his girlfriend, Sacha Santiago. A confrontation began when Irving Sanchez, the father of Santiago’s child, entered the salon. According to the defendant, Sanchez lifted his shirt to reveal a gun and said, “You know what’s about to happen.”
Believing his life was in danger, Santana-Rodriguez—who lawfully possessed a firearm—drew his pistol and fired two shots toward Sanchez. Sanchez was uninjured, but one round struck Trung Tran, a salon employee who was working nearby. Tran died of the wound.
Santana-Rodriguez was arrested at the scene and told police that he fired in self-defense. The Commonwealth indicted him for murder in the first degree under a theory of transferred intent, arguing that his intent to kill Sanchez could be legally “transferred” to the killing of Tran10-116-25.
The defense countered that if intent could transfer, so should justification—that the same right to self-defense should apply even if the bullet struck the wrong person. The trial judge reported the question of law to the Appeals Court, and the SJC took the case directly.
The Legal Question
Two questions were presented:
Whether Massachusetts law recognizes transferred-intent self-defense—that is, whether lawful self-defense against one person can excuse the accidental killing of another.
If so, whether that defense is complete (leading to acquittal) or partial (reducing the offense).
Until this case, Massachusetts had never formally recognized such a defense. The SJC had long applied transferred intent in homicide prosecutions—where a defendant aims at one person but kills another—but had never extended the doctrine to the justification side of the equation.
The SJC’s Decision
Writing for a unanimous Court, Justice Gaziano held that a defendant’s lawful self-defense can transfer to an unintended victim—but only if the defendant’s actions were not wanton or reckless.
In other words:
If the defendant used deadly force reasonably and lawfully in response to an imminent threat, the killing of a bystander may be justified.
If the defendant acted with wanton or reckless disregard for the risk to others, self-defense does not excuse the death. In that situation, the appropriate charge is involuntary manslaughter, not murder10-116-25.
The Court declined to follow Pennsylvania’s broader rule, which grants a complete defense even where the conduct was reckless. Instead, it adopted the approach used in most states, where justification extends to unintended victims only if the self-defense was exercised with reasonable care.
This creates a partial defense: it can eliminate a murder charge, but it does not preclude manslaughter liability.
Why the Court Drew This Line
The Court grounded its decision in two long-standing principles of Massachusetts law.
First, self-defense is lawful only when carried out reasonably—that is, when the person actually and reasonably believes deadly force is necessary to avoid death or serious harm, and uses no more force than required. If those elements are met, the act is justified and not criminal.
Second, Massachusetts criminal law punishes wanton or reckless conduct, not mere negligence. As the Court reaffirmed, conduct crosses from negligence into crime only when it involves “a high degree of likelihood that substantial harm will result to another.”10-116-25
By applying that standard to self-defense cases, the SJC avoided turning every tragic accident into a homicide, while still preserving accountability for reckless use of force in crowded or public settings.
A Model Jury Instruction
To guide future trials, the SJC appended a provisional model jury instruction. Judges should now instruct juries that:
A person is not guilty if he acted in proper self-defense.
If he acted in self-defense but did so in a wanton or reckless manner that caused the death of an innocent bystander, he may be guilty of involuntary manslaughter.
The instruction emphasizes that jurors must consider the defendant’s conduct “realistically,” allowing for the pressures and fear of a life-threatening moment. It also clarifies that ordinary negligence is not enough to establish criminal liability.
This instruction will likely appear in the next edition of the Model Jury Instructions on Homicide, giving judges and attorneys clear language for future cases.
Practical Impact for Defendants and Counsel
The Santana-Rodriguez decision gives both prosecutors and defense lawyers clearer boundaries when dealing with self-defense cases that involve unintended victims.
For the defense, it offers a recognized framework to argue that an act of self-defense remains lawful even when it causes unintended harm. Counsel can now request a transferred-intent self-defense instruction whenever the evidence supports it, and can argue for an involuntary-manslaughter verdict instead of murder when the shooting involved risk but not malice.
For the Commonwealth, the decision clarifies the burden of proof. Prosecutors must now establish beyond a reasonable doubt that the defendant’s self-defense was wanton or reckless if they wish to pursue a conviction for involuntary manslaughter. If the evidence shows a measured and reasonable defensive act, a murder conviction will not stand.
The Broader Context
The SJC’s reasoning builds upon earlier Massachusetts cases defining the scope of self-defense and manslaughter.
In Commonwealth v. Johnson (1992), the Court held that self-defense is not “an all-or-nothing proposition.”
In Commonwealth v. Hinds (2010), it recognized that excessive force in self-defense may reduce murder to voluntary manslaughter.
In Commonwealth v. Roman (2025), the Court reaffirmed that the Commonwealth must disprove self-defense beyond a reasonable doubt.
Santana-Rodriguez extends these principles to the unintended-victim scenario, clarifying that the same balance applies: self-defense remains a right, but it is bounded by reasonableness.
How the Decision May Affect Charging and Trial Strategy
1. Charging decisions. Prosecutors may now hesitate to pursue first-degree murder when the evidence shows genuine self-defense and a bystander death. Instead, they may charge involuntary manslaughter if they can show recklessness.
2. Jury instructions. Defense attorneys should request the SJC’s model instruction whenever a bystander is harmed during self-defense. This ensures that jurors understand the distinction between reasonable defense and reckless conduct.
3. Expert evidence. Ballistics, trajectory, and witness-location evidence will become more important. Demonstrating that a client fired in a narrow, controlled way may help show the absence of recklessness.
4. Negotiations and sentencing. The case gives both sides a common legal vocabulary for resolving homicide cases where the facts fall between full justification and full culpability.
Key Takeaways
Transferred-intent self-defense is now recognized in Massachusetts.
The defense applies when a person acts lawfully in self-defense but unintentionally kills a bystander.
It is a partial defense—it may eliminate a murder charge but allow conviction for involuntary manslaughter if the conduct was wanton or reckless.
The Court has provided a model jury instruction, signaling that this doctrine will have immediate practical application in trial courts.
The ruling reinforces the principle that Massachusetts criminal law punishes recklessness, not mere human error.
What This Means for Defendants
If you are charged with homicide after acting in what you believed was self-defense, this decision gives you new legal ground. Your attorney can now argue that your actions, if reasonable under the circumstances, should not be treated as murder—even if someone else was unintentionally harmed.
However, the case also underscores the importance of how force is used. The right to defend yourself is not unlimited. Using a firearm or other deadly weapon in a crowded or confined space can still result in serious criminal liability if the act is considered reckless.
Every case turns on its facts, including the immediacy of the threat, the space available to retreat, and the measures taken to avoid harming others. Effective defense representation now requires careful reconstruction of those details.
Conclusion
Commonwealth v. Santana-Rodriguez marks a significant evolution in Massachusetts self-defense law. It recognizes that a person’s right to protect his own life can, in some circumstances, extend to tragic outcomes he did not intend. At the same time, it preserves accountability when defensive acts are carried out without regard for others’ safety.
The decision reflects a balanced approach: compassionate toward those who act in genuine fear, but firm about the duty to avoid reckless harm. For judges, juries, and lawyers alike, it provides clear guidance on how to handle one of the hardest questions in criminal law—when self-defense and accident collide.
About Benzaken, Sheehan & Wood, LLP
Benzaken, Sheehan & Wood, LLP is a Massachusetts criminal-defense firm based in Brockton, representing clients statewide in serious state and federal cases, including homicide, firearms, and self-defense matters. Our attorneys have extensive trial and appellate experience and have appeared before both the Supreme Judicial Court and the Appeals Court.
If you or someone you love faces homicide or self-defense-related charges, contact our office for a confidential consultation. We are committed to providing skilled, practical, and compassionate representation when the stakes are highest.