Self-Defense and Mutual Combat in Massachusetts Domestic Violence Prosecutions

By Attorney Joe Serpa | Georgetown University Law Center | 30 Years Massachusetts Criminal Defense

Massachusetts police responding to a domestic call operate under a preferred-arrest policy and must decide in minutes, at a chaotic scene, usually from two conflicting accounts and whatever is visible: a red mark, a torn shirt, who is crying, who called 911. The person arrested is the person the officers judged, in that moment, to be the aggressor. In a meaningful share of cases charged under M.G.L. c. 265, § 13M in the Boston Municipal Court, the Quincy District Court, and every court in the Commonwealth, that snap judgment is wrong: the arrested person was defending against the other’s violence, or both parties were combatants and the police picked one. Self-defense in this setting is not an exotic theory. Properly developed, it is one of the most common and most powerful paths to a not-guilty verdict in a domestic violence trial.

The Burden Belongs to the Commonwealth

Self-defense in Massachusetts is not an affirmative defense the accused must prove. Once the evidence, from any source, including the Commonwealth’s own witnesses, raises the issue, the Commonwealth must prove beyond a reasonable doubt that the defendant did not act in self-defense. Commonwealth v. Rodriguez, 370 Mass. 684, 687-688 (1976). For non-deadly force, the jury asks whether the defendant reasonably and actually believed he was being attacked or immediately about to be attacked, whether he used no more force than reasonably necessary in the circumstances, and, outside the home, whether he availed himself of reasonable means of escape before resorting to force. The force must be proportional; the right to defend against a shove does not license a response the law treats as deadly force. Commonwealth v. Santos, 454 Mass. 770 (2009). These are the Commonwealth’s elements to disprove, not the defendant’s to establish, and that allocation is the spine of the defense.

No Duty to Retreat in Your Own Home

Because most domestic allegations arise inside a shared residence, the retreat question is frequently governed by statute. Under M.G.L. c. 278, § 8A, an occupant who is attacked within his dwelling by an intruder has no duty to retreat before using reasonable force, including, where he reasonably believes he is in imminent danger of great bodily injury or death, deadly force. The statute’s application between two lawful co-occupants of the same home, the usual domestic posture, raises genuine questions that must be litigated carefully on the facts, but the core principle, that a person is not required to flee his own home before defending himself, removes from many domestic cases the retreat element the Commonwealth would otherwise press. Whether the defendant could have walked away is, inside the home, frequently the wrong question as a matter of law.

The First-Aggressor Question and Adjutant Evidence

Domestic trials often reduce to a single disputed fact: who started the physical confrontation. Massachusetts law gives the defense a specific and underused tool. Under Commonwealth v. Adjutant, 443 Mass. 649 (2005), where the identity of the first aggressor is in dispute, the defense may introduce evidence of the complainant’s specific prior acts of violence, even acts the defendant did not know about at the time, as probative of who was more likely the aggressor in the incident charged. In a relationship with a documented two-way history, prior police responses to either party, prior cross-complaints, prior 209A applications each filed against the other, Adjutant evidence can reframe the entire trial, converting the Commonwealth’s tidy aggressor-and-victim narrative into a factual contest the jury must resolve against the defendant beyond a reasonable doubt. Building it requires early and aggressive investigation: incident reports from every prior address, the complainant’s own record where obtainable, and the paper trail of any prior 209A proceedings, gathered before memories and records fade.

Mutual Combat and the Complainant’s Own Exposure

Where the evidence shows both parties were violent, the consequences run in two directions at once. For the defense, mutual combat frames the reasonableness of the defendant’s responsive force and dismantles the one-sided-assault story the arrest was built on. For the complainant, it creates real criminal exposure, and with that exposure a Fifth Amendment privilege: a witness whose truthful testimony would admit an assault, a threat under M.G.L. c. 275, § 2, or destruction of property may, after judicial inquiry and consultation with counsel, decline to testify. Combined with the spousal privilege under M.G.L. c. 233, § 20, this is why so many genuinely mutual cases resolve in trial-date dismissals. But the privileges belong to the witness, and here the warning is the same one that governs recantation: no defendant may ever discuss the case, the testimony, or the privileges with the complainant, because that path leads directly to a witness intimidation charge under M.G.L. c. 268, § 13B and to forfeiture of the very confrontation and hearsay objections the defense needs. The work runs through counsel, always.

Injuries, Photographs, and the Wrong-Arrest Problem

Defense of these cases is physical-evidence work, done fast. Defensive injuries on the defendant, scratches on the forearms, bite marks, wounds to the hands, tell the story the arrest got backward, and they fade within days, so they are photographed immediately and documented in medical records. The 911 audio is obtained and studied, because the voice that sounds like the aggressor on the call frequently belongs to the person who was not arrested. Body-worn camera footage is preserved before agency retention periods lapse. Medical records are read against the claimed mechanism of injury to test whether the account is even physically possible. Excited-utterance statements captured on scene are analyzed for what they actually show about sequence and aggression. Attorney Serpa has tried domestic violence cases to not-guilty verdicts across Massachusetts for thirty years, and these trials are won with a record assembled in the first weeks, not the last; representative outcomes are at Massachusetts Criminal Defense Results.

Why These Cases Often Must Be Tried: Professionals, Students, Non-Citizens

The self-defense case is frequently the case that must be tried rather than pled, precisely because the client cannot absorb the collateral consequences of any admission. A nurse or physician with a board license, a teacher, a securities-registered professional, a university student facing a parallel Title IX proceeding, a License to Carry holder facing suitability review under St. 2024, c. 135, a lawful permanent resident for whom a CWOF on a domestic charge is a federal conviction, for each of these clients a plea that resolves the criminal case can detonate the rest of a life, so the correct answer is often to make the Commonwealth prove a case it cannot prove; see Domestic Violence Charges and Immigration in Massachusetts and Boston domestic violence defense. Trial readiness in these cases is not posture; it is the plan from the first court date, whether in the BMC divisions, Dedham, Newton, Somerville, or any court in the region; see the complete court guide.

Key Takeaways. Once self-defense is raised by any evidence, the Commonwealth must disprove it beyond a reasonable doubt under Commonwealth v. Rodriguez. There is no duty to retreat before defending yourself in your own dwelling under M.G.L. c. 278, § 8A. Where the first aggressor is disputed, Commonwealth v. Adjutant permits evidence of the complainant’s prior violent acts. Mutual combat gives the complainant a Fifth Amendment privilege that frequently leads to a trial-date dismissal, but the defendant must never discuss it with the witness, on pain of a felony intimidation charge and forfeiture by wrongdoing. These cases are won with immediate preservation of injuries, 911 audio, and body-camera footage, and with trial preparation from day one, especially for professionals, students, and non-citizens who cannot absorb any admission.

Contact Serpa Law Office at 617.936.0201. Boston office: 20 Park Plaza #400A. Quincy office: 500 Victory Rd., Suite 400A. Available 24 hours a day.

Related Serpa Law Office resources

• Assault and Battery on a Family or Household Member (M.G.L. c. 265, § 13M)
• Strangulation or Suffocation (M.G.L. c. 265, § 15D)
• Intimidation of a Witness (M.G.L. c. 268, § 13B)
• Massachusetts 209A Restraining Orders and Abuse Prevention Orders
• Massachusetts Domestic Violence Law FAQs
• Massachusetts Criminal Defense Results
• Boston Domestic Violence Defense Lawyer