Massachusetts Manslaughter Laws: OUI Manslaughter and Vehicle Homicide

Massachusetts has a single crime of manslaughter, defined by the courts rather than by statute; General Laws chapter 265, section 13 sets its penalty at up to 20 years in state prison, or alternatively a fine of up to $1,000 and up to 2 1/2 years in jail or a house of correction. It is a felony, because it is punishable by state prison (G.L. c. 274, s. 1).

The Supreme Judicial Court recognizes two forms, voluntary and involuntary manslaughter. Deaths caused by impaired or careless driving are covered by separate statutes: manslaughter while operating under the influence (c. 265, s. 13 1/2, 5 to 20 years) and the homicide by a motor vehicle offenses in c. 90, s. 24G. For how other states define and grade the same conduct, see our guide to manslaughter laws by state.

Information last verified on October 18, 2026. This article has not been reviewed by a licensed lawyer.

Jurisdiction scope: This article covers Massachusetts criminal law on homicide below murder: the manslaughter penalty in G.L. c. 265, s. 13, the common-law definitions of voluntary and involuntary manslaughter, manslaughter while operating under the influence (c. 265, s. 13 1/2), homicide by a motor vehicle (c. 90, s. 24G), homicide by a vessel (c. 90B, s. 8B), leaving the scene of a fatal collision (c. 90, s. 24), license revocation, parole eligibility, the firearm add-on (c. 265, s. 18B), the habitual offender law (c. 279, s. 25), the viable-fetus rule for vehicle homicide, and other offenses connected to a death. It does not cover murder (see how long a life sentence is in Massachusetts and murder sentencing guidelines), self-defense (see Massachusetts self-defense laws), civil lawsuits over a death (see Massachusetts wrongful death), or federal offenses (see the manslaughter laws hub).

What is manslaughter in Massachusetts?

Section 13 of chapter 265 does not define manslaughter. It sets the punishment:

"Section 13. Whoever commits manslaughter shall, except as hereinafter provided, be punished by imprisonment in the state prison for not more than twenty years or by a fine of not more than one thousand dollars and imprisonment in jail or a house of correction for not more than two and one half years."

The definitions come from decisions of the Supreme Judicial Court (SJC). The General Laws contain no numbered degrees of manslaughter and no general statutory definition of "recklessly" or "criminal negligence" for the criminal code; the only statutory definition of reckless operation is in c. 90, s. 24G(c), and it applies to that section only.

Voluntary manslaughter. In Commonwealth v. Acevedo, 446 Mass. 435 (2006), the SJC described it as an unlawful killing "arising not from malice, but 'from . . . sudden passion induced by reasonable provocation, sudden combat, or excessive force in self-defense.'"

Involuntary manslaughter. In Commonwealth v. Life Care Centers of America, Inc., 456 Mass. 826 (2010), the SJC repeated its definition: involuntary manslaughter is "an unlawful homicide unintentionally caused by an act which constitutes such a disregard of probable harmful consequences to another as to amount to wanton or reckless conduct."

The SJC's Model Jury Instructions on Homicide recognize a second form: "an unlawful killing unintentionally caused by a battery that the defendant knew or should have known endangered human life," limited by the case law to a battery that is not a felony.

The main homicide offenses below murder in Massachusetts are:

• Manslaughter (common law, penalty in G.L. c. 265, s. 13), covering voluntary and involuntary manslaughter.
• Manslaughter while operating under the influence (c. 265, s. 13 1/2), for a motor vehicle or a boat.
• Homicide by a motor vehicle while under the influence of an intoxicating substance (c. 90, s. 24G(a)).
• Homicide by a motor vehicle (c. 90, s. 24G(b)).
• Reckless homicide by a motor vehicle (c. 90, s. 24G(c)).
• Homicide by a vessel while under the influence and homicide by a vessel (c. 90B, s. 8B).

Viable fetus. Massachusetts has no separate fetal-homicide statute. In Commonwealth v. Cass, 392 Mass. 799 (1984), the SJC stated: "A viable fetus is a 'person' for purposes of the vehicular homicide statute as applied to homicides occurring after the date of this decision."

Is manslaughter a felony in Massachusetts? Offenses and penalties

Massachusetts does not use felony classes. Under G.L. c. 274, s. 1, "A crime punishable by death or imprisonment in the state prison is a felony. All other crimes are misdemeanors." Manslaughter, manslaughter while operating under the influence and reckless homicide by a motor vehicle can all be punished by state prison, so they are felonies. Homicide by a motor vehicle under s. 24G(b) is punishable only in a jail or house of correction, so under that test it is a misdemeanor.

A business organization that commits manslaughter "shall be punished by a fine of not more than $250,000" under c. 265, s. 13, and the appropriate commissioner or secretary may debar it under c. 29, s. 29F "for a period of not more than 10 years." Section 13 itself sets no minimum term for ordinary manslaughter. A state-prison sentence for manslaughter is indeterminate: the judge sets a minimum and a maximum term, the maximum no longer than the 20 years the law allows and the minimum at least 1 year, because a house-of-correction sentence is also permitted (G.L. c. 279, s. 24). A prisoner sentenced to state prison becomes eligible for parole after serving the minimum term, as reduced by deductions under c. 127, s. 129D (c. 127, s. 133). For how Massachusetts labels felonies and misdemeanors more generally, see Massachusetts felony and misdemeanor classes.

Voluntary manslaughter and reasonable provocation

Acevedo identifies three routes to voluntary manslaughter: sudden passion induced by reasonable provocation, sudden combat, and excessive force in self-defense. On provocation, the SJC explained that reasonable provocation is provocation that "would have been likely to produce in an ordinary person such a state of passion, anger, fear, fright, or nervous excitement as would eclipse his capacity for reflection or restraint."

The court also stated when a jury should be instructed on it: an instruction on reasonable provocation is warranted "if there is evidence of provocation deemed adequate in law to cause the accused to lose his self-control in the heat of passion, and if the killing followed the provocation before sufficient time had elapsed for the accused's temper to cool."

The text of c. 265, s. 13 says nothing about provocation, so the standard comes entirely from the SJC's decisions. Excessive force in self-defense is a manslaughter theory; whether force was justified at all is covered on the Massachusetts self-defense laws page.

Involuntary manslaughter: wanton or reckless conduct

Involuntary manslaughter turns on "wanton or reckless conduct." The leading description comes from Commonwealth v. Welansky, 316 Mass. 383 (1944):

"The essence of wanton or reckless conduct is intentional conduct, by way either of commission or of omission where there is a duty to act, which conduct involves a high degree of likelihood that substantial harm will result to another."

In Life Care Centers, the SJC added that "reckless conduct does not require that the actor intend the specific result of his or her conduct, but only that he or she intended to do the reckless act."

One statute ties a specific act to this standard. Under the firearm storage law, G.L. c. 140, s. 131L(e), a storage violation "shall be evidence of wanton or reckless conduct in any criminal or civil proceeding" if a person under 18 who was not a trespasser, or was a foreseeable trespasser, acquired access to a firearm (unless that person held a valid firearm identification card and was permitted by law to possess it), "and such access results in the personal injury to or the death of any person."

Vehicular manslaughter and OUI deaths in Massachusetts

Massachusetts has two layers for driving deaths: manslaughter while operating under the influence in chapter 265, and the three homicide by a motor vehicle offenses in c. 90, s. 24G. A death caused with a motor vehicle can also be punished as ordinary manslaughter under c. 265, s. 13; the license-revocation rule in s. 24G(d) expressly covers a person "punished under section 13 of chapter 265" when a motor vehicle is the instrument of the offense.

Manslaughter while operating under the influence (c. 265, s. 13 1/2)

"Whoever commits manslaughter while operating a motor vehicle in violation of paragraph (a) of subdivision (1) of section 24 of chapter 90 or section 8A of chapter 90B, shall be punished by imprisonment in the state prison for not less than 5 years and not more than 20 years, and by a fine of not more than $25,000."

The offense requires both a manslaughter and an operating-under-the-influence violation. The sentence "shall not be reduced to less than 5 years, nor suspended, nor shall any such person be eligible for probation, parole or furlough or receive a deduction from his sentence for good conduct until he shall have served 5 years of such sentence." On notice of a conviction, the registrar "may suspend the license or right to operate of such person for any extended period up to life, provided that such suspension be at least a 15 year period."

Homicide by a motor vehicle while under the influence (c. 90, s. 24G(a))

This offense applies to a person who, on a way or place to which the public has a right of access, operates a motor vehicle "with a percentage, by weight, of alcohol in their blood of.08 or greater, or while under the influence of intoxicating liquor, or of marijuana, narcotic drugs, depressants or stimulant substances," and "so operates a motor vehicle recklessly or negligently so that the lives or safety of the public might be endangered, and by any such operation so described causes the death of another person."

The penalty is 2 1/2 to 15 years in state prison and a fine of up to $5,000, or 1 to 2 1/2 years in a jail or house of correction and a fine of up to $5,000. The sentence "shall not be reduced to less than 1 year, nor suspended," and the person is not eligible for probation, parole or furlough or any deduction until at least 1 year has been served. Prosecutions under the section "shall neither be continued without a finding nor placed on file."

Homicide by a motor vehicle (c. 90, s. 24G(b))

The official text of subsection (b) reads:

"(b) Whoever, upon any way or in any place to which the public has a right of access or upon any way or in any place to which members of the public have access as invitees or licensees, operates a motor vehicle with a percentage, by weight, of alcohol in their blood of.08 or greater, or while under the influence of intoxicating liquor, or of marijuana, narcotic drugs, depressants or stimulant substances, all as defined in section 1 of chapter 94C, or from smelling or inhaling the fumes of any substance having the property of releasing toxic vapors as defined in section 18 of chapter 270, or whoever operates a motor vehicle negligently so that the lives or safety of the public might be endangered and by any such operation causes the death of another person, shall be guilty of homicide by a motor vehicle and shall be punished by imprisonment in a jail or house of correction for not less than 30 days nor more than 21/2 years, or by a fine of not less than $300 nor more than $3,000 dollars, or both."

As printed, the subsection joins an impaired-operation clause and a negligent-operation clause with "or whoever." The penalty is 30 days to 2 1/2 years in a jail or house of correction, a fine of $300 to $3,000, or both.

Reckless homicide by a motor vehicle (c. 90, s. 24G(c))

Subsection (c) covers a person who "operates a motor vehicle recklessly so that the lives or safety of the public might be endangered and by any such operation causes the death of another person." For that section only, "a person operates recklessly when that person consciously disregards a substantial and unjustifiable risk that the lives or safety of the public might be endangered." The penalty is up to 2 1/2 years in a jail or house of correction, up to 5 years in state prison, a fine of up to $3,000, or both fine and imprisonment.

License revocation

Under c. 90, s. 24G(d), "When a motor vehicle is the instrument of the offense, the registrar shall revoke the license or right to operate of a person convicted of a violation of subsection (a), (b) or (c), or punished under section 13 of chapter 265, for a period of 15 years after the date of conviction for a first offense." A subsequent violation means revocation "for the life of such person."

The non-fatal companion offense, operating under the influence and causing serious bodily injury (c. 90, s. 24L), carries 2 1/2 to 10 years in state prison or 6 months to 2 1/2 years in a house of correction, plus a fine of up to $5,000 and at least 6 months served, where the operation was also reckless or negligent (s. 24L(1)); without that element, up to 2 1/2 years in a jail or house of correction, a fine of at least $3,000, or both (s. 24L(2)). For OUI penalties where no one is hurt, see Massachusetts DUI laws.

Leaving the scene of a fatal collision

A driver who, without stopping and making known his name, residence and registration number, "goes away to avoid prosecution or evade apprehension after knowingly colliding with or otherwise causing injury to any person" faces, "if the injuries result in the death of a person," 2 1/2 to 10 years in state prison or 1 to 2 1/2 years in a jail or house of correction, plus a fine of $1,000 to $5,000 (c. 90, s. 24(2)(a 1/2)(2)). The sentence may not be reduced below 1 year or suspended, with no probation, parole or furlough before 1 year is served. See Massachusetts hit-and-run laws.

Refusing to stop for a police officer under c. 90, s. 25 is punishable by a fine of one hundred dollars, and drag racing under c. 90, s. 17B by up to 2 1/2 years in a house of correction or a fine of up to $1,000; neither section has a tier for a death.

Boating deaths

Manslaughter while operating a boat under the influence in violation of c. 90B, s. 8A falls under c. 265, s. 13 1/2, with the same 5-to-20-year penalty. Chapter 90B, s. 8B adds two vessel offenses:

• Homicide by a vessel while under the influence of an intoxicating substance (s. 8B(1)): 2 1/2 to 15 years in state prison, or 1 to 2 1/2 years in a jail or house of correction, and a fine of up to $5,000, with at least 1 year served before probation or parole. Prosecutions under s. 8B "shall neither be continued without a finding nor placed on file."
• Homicide by a vessel (s. 8B(2)), impaired operation or reckless or negligent operation causing a death: 30 days to 2 1/2 years in a jail or house of correction, or a fine of $300 to $3,000, or both.

The operator's license or certificate is revoked for 10 years after a first conviction and for life after a subsequent one (s. 8B(3)).

Other offenses graded by a resulting death

• Manslaughter while violating c. 266, ss. 102 to 102C, G.L. c. 265, s. 13: state prison for life or for any term of years.
• Firearm storage leading to a minor's access, G.L. c. 140, s. 131L(e): no separate death offense, but a violation is evidence of wanton or reckless conduct where the access results in injury or death (see above).

Sentencing: habitual offenders, firearms and registration

Habitual offenders (c. 279, s. 25(b)). Manslaughter (c. 265, s. 13) and manslaughter while operating under the influence (s. 13 1/2) are among the offenses listed in s. 25(b). A person convicted of a listed offense who has been convicted 2 times previously of listed offenses, "arising out of charges separately brought and tried, and arising out of separate and distinct incidents," and who was sentenced to at least 3 years in a state or federal prison for each of the prior 2 convictions, "shall be considered a habitual offender and shall be imprisoned in the state prison or state correctional facility for the maximum term provided by law for the offense enumerated in clause (i)." For ordinary manslaughter, the maximum provided by c. 265, s. 13 is 20 years. Under s. 25(b), no such sentence may be reduced or suspended, and the person is not eligible for probation, parole or work release.

Separately, s. 25(a) treats a person convicted of any felony, who has been twice previously convicted and sentenced to a state or federal prison for a term of not less than 3 years, as a habitual criminal who must be punished by imprisonment in state prison "for such felony for the maximum term provided by law." That rule is not limited to the offenses listed in s. 25(b), so it also reaches the felony vehicle and vessel homicide offenses.

Firearms (c. 265, s. 18B). Possessing or controlling a firearm while committing an offense punishable by state prison, which includes manslaughter, is punished, "in addition to the penalty for such offense," by at least 5 years in state prison; at least 10 years if the firearm is a large capacity firearm or a machine gun; and at least 20 years for a second or subsequent such offense.

Registration. The Massachusetts sex offender registry law defines "sex offense" in G.L. c. 6, s. 178C by a list of sex crimes, and manslaughter is not on that list.

Federal law (18 U.S.C. 1112) separately covers manslaughter on federal land and in other places under federal jurisdiction; the manslaughter laws hub explains it.

Leading Massachusetts cases

• Commonwealth v. Welansky, 316 Mass. 383 (1944): "The essence of wanton or reckless conduct is intentional conduct, by way either of commission or of omission where there is a duty to act, which conduct involves a high degree of likelihood that substantial harm will result to another."
• Commonwealth v. Acevedo, 446 Mass. 435 (2006): voluntary manslaughter arises from sudden passion induced by reasonable provocation, sudden combat, or excessive force in self-defense, and a provocation instruction requires that the killing followed the provocation before the accused's temper had time to cool.
• Commonwealth v. Life Care Centers of America, Inc., 456 Mass. 826 (2010): involuntary manslaughter is an unintentional unlawful homicide caused by wanton or reckless conduct, and recklessness requires intending the reckless act, not the specific result.

Related Massachusetts laws

• Manslaughter laws by state
• Massachusetts DUI laws
• Massachusetts hit-and-run laws
• Massachusetts self-defense laws
• Massachusetts felony and misdemeanor classes
• Murder, homicide and manslaughter: the differences

This article provides general legal information about Massachusetts law, not legal advice. Statutes and court decisions change, and how they apply depends on the facts. For advice about a specific situation, contact a lawyer licensed in Massachusetts.

Last updated: October 18, 2026.

Frequently Asked Questions

Is manslaughter a felony in Massachusetts?

Yes. Under G.L. c. 274, s. 1, a crime punishable by state prison is a felony, and manslaughter is punishable by up to 20 years in state prison under c. 265, s. 13.

What is the sentence for manslaughter in Massachusetts?

Up to 20 years in state prison, or a fine of up to $1,000 and up to 2 1/2 years in jail or a house of correction (G.L. c. 265, s. 13). Manslaughter while violating c. 266, ss. 102 to 102C carries life or any term of years, and OUI manslaughter carries 5 to 20 years.

What is the difference between voluntary and involuntary manslaughter in Massachusetts?

Voluntary manslaughter is an unlawful killing from sudden passion induced by reasonable provocation, sudden combat, or excessive force in self-defense (Commonwealth v. Acevedo). Involuntary manslaughter is an unintentional unlawful homicide caused by wanton or reckless conduct (Commonwealth v. Life Care Centers), or by a battery not amounting to a felony that the defendant knew or should have known endangered human life (SJC Model Jury Instructions on Homicide).

What is vehicular manslaughter in Massachusetts?

Massachusetts uses several offenses. Manslaughter while operating under the influence (G.L. c. 265, s. 13 1/2) carries 5 to 20 years. Chapter 90, s. 24G covers homicide by a motor vehicle while under the influence (2 1/2 to 15 years in state prison or 1 to 2 1/2 years in jail), homicide by a motor vehicle (30 days to 2 1/2 years), and reckless homicide by a motor vehicle (up to 5 years in state prison).

Is there a mandatory minimum for an OUI death in Massachusetts?

Yes. A sentence under c. 265, s. 13 1/2 cannot be reduced below 5 years or suspended, with no probation, parole or furlough until 5 years are served. Under c. 90, s. 24G(a), the sentence cannot be reduced below 1 year, with no probation or parole until 1 year is served.

How long is a license revoked after a vehicle homicide in Massachusetts?

When a motor vehicle is the instrument of the offense, the registrar revokes the license for 15 years after a first conviction under c. 90, s. 24G or punishment under c. 265, s. 13, and for life after a subsequent violation of s. 24G (c. 90, s. 24G(d)).

Does Massachusetts law define provocation by statute?

No. G.L. c. 265, s. 13 sets only the penalty. The SJC defines reasonable provocation as provocation likely to produce in an ordinary person a state of passion, anger, fear, fright or nervous excitement that would eclipse the capacity for reflection or restraint (Commonwealth v. Acevedo).