Self-Defense and Mutual Combat in Massachusetts Domestic Violence Cases

When both people used force during a domestic incident, the arrest decision does not resolve whether either person acted in self-defense. The criminal case requires a closer analysis of who initiated the confrontation, whether either person agreed to fight, how the force escalated, and whether the defendant’s response was reasonably necessary.

Correction, August 16, 2026: An earlier version of this article attributed Adjutant holdings to Commonwealth v. Ramos, SJC-12678. That case is Commonwealth v. Jose Ramos, 490 Mass. 818 (2022), a postconviction DNA-testing decision under G.L. c. 278A. This article has been rewritten after primary-source review.

Those distinctions matter in prosecutions for assault or assault and battery on a family or household member under G.L. c. 265, § 13M. They also matter when the Commonwealth charges simple assault and battery, assault and battery with a dangerous weapon, strangulation, or another offense arising from the same event.

Self-Defense Remains the Commonwealth’s Burden

Self-defense in Massachusetts is a complete justification. Once the evidence fairly raises it, the defendant bears no burden of persuasion. The Commonwealth must prove beyond a reasonable doubt at least one applicable proposition that defeats the defense. If it proves none of the applicable propositions, the verdict must be not guilty.

For nondeadly force, the current Massachusetts model instruction addresses an actual and objectively reasonable concern for immediate personal safety. It also addresses reasonable efforts to avoid combat, proportional force, and whether the defendant was the first aggressor. Deadly force is governed by a separate and more demanding standard.

Evidence that both people made physical contact does not by itself disprove self-defense. One person may have attacked and the other may have responded with reasonably necessary force. The sequence, the level of force, and any opportunity to avoid further combat must be evaluated from the evidence rather than the arrest label.

Mutual Combat Is Not the Same as Self-Defense

The term “mutual combat” has a narrower meaning than an incident in which both people used force. The notes to the Massachusetts self-defense instructions explain that when two people agree to engage in a fistfight, neither generally acts in self-defense because neither used all reasonable means to avoid combat.

An agreement to fight can be express or inferred from conduct, but it should not be assumed merely because each person struck the other. A responsive use of force after an unlawful attack is analytically different from a fight entered by agreement. The jury must consider the circumstances leading to the first physical act and what each person did next.

Withdrawal and Unexpected Escalation

A first aggressor may regain the right to self-defense by withdrawing in good faith and clearly communicating that withdrawal. If the other person continues the attack, the renewed use of force must still satisfy the requirements of necessity and proportionality.

Massachusetts law also recognizes an important limit on agreed combat. A person may regain the right to defend if that person actually believes the other participant, contrary to their mutual understanding, has introduced or threatened deadly force, and that belief is objectively reasonable. The responsive force must still satisfy the applicable requirements of reasonable avoidance, necessity, and proportionality.

Shared Homes Do Not Create an Automatic No-Retreat Rule

Massachusetts’s dwelling statute is often misstated in domestic cases. G.L. c. 278, § 8A removes the duty to retreat when a lawful occupant is charged with killing or injuring a person unlawfully in the dwelling, reasonably believes that person is about to inflict great bodily injury or death on the occupant or another lawful occupant, and uses reasonable means to defend.

The statute does not create an automatic no-retreat rule between two lawful occupants of the same home. In that setting, the ordinary self-defense analysis includes whether the defendant used or attempted to use all reasonable means available to avoid physical combat. A person need not take an unsafe avenue of retreat, but shared residence alone does not remove the avoidance requirement.

First-Aggressor Evidence Under Adjutant

When the identity of the first aggressor or the first person to use or threaten deadly force is genuinely disputed, the defense may ask the judge to admit qualifying specific-act evidence. The Adjutant rule can include specific violent incidents that the alleged victim is reasonably alleged to have initiated, even if the defendant did not know about them at the time.

The rule is discretionary and does not make a police report, charge, or docket entry automatically admissible. Ordinary evidence rules still apply. Massachusetts Rule of Criminal Procedure 14.3(c) requires detailed written notice no later than 21 days after the pretrial hearing, unless the judge sets another time for good cause.

Offering this evidence can permit a response from the Commonwealth. Under Commonwealth v. Morales, the prosecution may seek to admit specific incidents of the defendant’s prior violent conduct. The firm’s detailed article on Adjutant evidence and prosecution rebuttal explains the governing limits, reciprocal notice, balancing test, and limiting instructions.

The Fifth Amendment and Spousal Rules Are Separate

A complaining witness who may have committed an offense during the same incident can have a valid privilege against self-incrimination. The privilege is not automatic merely because both people used force. Under Massachusetts Guide to Evidence § 511, the judge determines whether an answer could present a real danger of legal detriment.

The privilege ordinarily must be asserted in response to particular questions. A witness may be permitted to assert it more broadly when most or all relevant questions would create the same danger. Statutory immunity may be available in some proceedings and for some offenses. If immunity is lawfully granted, the witness can be compelled to testify within its scope.

The spousal testimonial rule is different. Under G.L. c. 233, § 20, a currently married witness-spouse generally cannot be compelled to testify against the defendant-spouse at the trial of a criminal case, subject to statutory exceptions. The choice belongs to the witness-spouse. The separate rule for private marital communications has different exceptions and should not be treated as the same privilege.

Neither privilege guarantees dismissal. The Commonwealth may have other admissible evidence, the court may reject an unsupported Fifth Amendment claim, and the scope of a valid privilege may be narrower than the prosecution’s entire examination.

Contact with the Complaining Witness Can Create New Charges

A defendant should not discuss testimony, nonappearance, recantation, or privilege with the complaining witness. Contact may violate a release condition or a 209A order even when the witness initiated it.

G.L. c. 268, § 13B applies to specified willful conduct against a covered person. The statute includes threats, attempts or acts causing physical, emotional, or economic injury or property damage; offers of value; and misleading conduct, intimidation, or harassment.

The Commonwealth must also prove the required mental state. It must prove intent to interfere with a listed proceeding or to punish, harm, or otherwise retaliate against a covered person for participation in one, or reckless disregard that the conduct may have either effect.

Forfeiture by wrongdoing is also not automatic. The Commonwealth must establish the governing intent and causation requirements, and Massachusetts adds a reliability requirement for the statement it seeks to admit. A routine conversation is not necessarily intimidation or forfeiture, but direct contact about the case can create serious evidentiary and criminal consequences. Communication should proceed through counsel.

A Missing Witness Does Not End the Evidence Analysis

The prosecution does not control a witness’s privilege, but it does decide whether to continue the case with other evidence. Police observations, authenticated recordings, photographs, medical evidence, and a defendant’s admissible statements may remain available. Recorded statements require a separate hearsay analysis, and testimonial statements may also implicate the Confrontation Clause.

A 911 statement or body-camera recording is not automatically admissible merely because it was recorded. The purpose and circumstances of the statement matter. The firm’s discussions of excited utterances and the Confrontation Clause and recantation in domestic violence cases explain those separate issues.

Evidence That Can Distinguish Defense from Aggression

Self-defense analysis begins with the sequence of events. A complete 911 recording may show who sought help, what was said before police arrived, and whether either account changed. Body-camera footage may show demeanor, injuries, the physical setting, and statements made close in time to the incident.

Injuries should be documented promptly and from more than one angle. Medical records may help explain whether an injury is consistent with offensive or defensive conduct. Digital evidence should be preserved in full rather than as selected screenshots. The messages before and after the event may provide context that a single image omits.

Prior incidents require their own proof. A defense investigation may identify witnesses, recordings, photographs, or court records that lead to admissible evidence. The investigation should also account for potential rebuttal concerning the defendant. The decision to offer first-aggressor evidence should follow that complete assessment.

Building a Domestic Self-Defense Case

A careful defense identifies the charged form of assault or battery, the level of force the Commonwealth alleges, and every applicable self-defense proposition. It then tests each item of evidence for admissibility and completeness. The broader Massachusetts domestic-violence defense page explains the criminal process and the civil proceedings that may occur at the same time.

Serpa Law Office represents defendants in domestic assault, self-defense, dangerous-weapon, strangulation, and related cases throughout Massachusetts. Call 617-936-0201 or use the contact form to request a confidential consultation.