New Mexico Manslaughter Laws: Voluntary, Involuntary and DWI Deaths

New Mexico defines manslaughter as "the unlawful killing of a human being without malice" and splits it into voluntary manslaughter, committed upon a sudden quarrel or in the heat of passion, and involuntary manslaughter, committed in an unlawful act not amounting to a felony or in a lawful act done without due caution and circumspection (NMSA 30-2-3). Voluntary manslaughter is a third degree felony resulting in the death of a human being, with a 6-year basic sentence, and involuntary manslaughter is a fourth degree felony, with an 18-month basic sentence (31-18-15).

Deaths caused by driving are a separate Motor Vehicle Code offense, homicide by vehicle (66-8-101), which is a second degree felony when the driver is under the influence and a third degree felony when the driver is violating the reckless driving statute. For other states, see our guide to manslaughter laws by state.

Information last verified on 2026-10-17. This article has not been reviewed by a licensed lawyer.

Jurisdiction scope: This article covers the New Mexico criminal statutes on homicide below murder: voluntary and involuntary manslaughter (NMSA 30-2-3), assisting suicide (30-2-4), homicide by vehicle (66-8-101), leaving the scene of an accident resulting in great bodily harm or death (66-7-201), the unborn-victim offenses of injury to pregnant woman (30-3-7) and injury to pregnant woman by vehicle (66-8-101.1), and the sentencing and earned-time rules that apply to them. It does not cover murder (see how long a life sentence is in New Mexico and our overview of murder sentencing), self-defense and justification (see New Mexico self-defense laws), civil lawsuits over a death (see New Mexico wrongful death law), or federal manslaughter, which our manslaughter laws hub covers.

What is manslaughter in New Mexico?

Section 30-2-3 of the New Mexico Statutes Annotated sets out the whole offense in one paragraph:

"Manslaughter is the unlawful killing of a human being without malice. A. Voluntary manslaughter consists of manslaughter committed upon a sudden quarrel or in the heat of passion. Whoever commits voluntary manslaughter is guilty of a third degree felony resulting in the death of a human being. B. Involuntary manslaughter consists of manslaughter committed in the commission of an unlawful act not amounting to felony, or in the commission of a lawful act which might produce death in an unlawful manner or without due caution and circumspection. Whoever commits involuntary manslaughter is guilty of a fourth degree felony." (NMSA 30-2-3)

The absence of malice is what separates manslaughter from murder. New Mexico's second degree murder subsection, 30-2-1(B), opens with the same carve-out: "Unless he is acting upon sufficient provocation, upon a sudden quarrel or in the heat of passion."

Manslaughter offenses and penalties in New Mexico

New Mexico sentences felonies by degree under 31-18-15, which sets a "basic sentence" for each degree. The table in that section lists a separate, higher row for a felony "resulting in the death of a human being": 6 years for a third degree felony resulting in death (compared with 3 years for a third degree felony) and 18 years for a second degree felony resulting in death. A fourth degree felony carries 18 months. The fine figures are $12,500 for a second degree felony resulting in death and $5,000 for a third degree felony resulting in death and for a third or fourth degree felony (31-18-15(E)).

The voluntary manslaughter statute expressly uses the "resulting in the death of a human being" grade. The homicide by vehicle subsections direct sentencing "pursuant to the provisions of Section 31-18-15" without using that phrase, so the table above gives both rows for the reckless form. For how New Mexico sorts crimes into degrees, see New Mexico felony and misdemeanor classes.

Voluntary manslaughter: sudden quarrel or heat of passion

Section 30-2-3(A) defines voluntary manslaughter as "manslaughter committed upon a sudden quarrel or in the heat of passion." The statute does not use the word provocation, but the murder statute does: second degree murder applies "Unless he is acting upon sufficient provocation, upon a sudden quarrel or in the heat of passion" (30-2-1(B)).

Panic defense ban. New Mexico bars a category of these claims by statute. Section 30-1-16, enacted by Laws 2022, ch. 56, s. 52 and effective May 18, 2022, sits in the general provisions of the Criminal Code and applies in any criminal proceeding:

"A. It shall not be a defense, justification or excuse in a criminal proceeding that the defendant's conduct was a reaction to the discovery of, knowledge about or potential disclosure of a victim's or witness's actual or perceived: (1) gender; (2) gender expression; (3) gender identity; or (4) sexual orientation. B. It shall not be a defense, justification or excuse in a criminal proceeding that the defendant was romantically propositioned in a nonviolent or non-threatening manner by a person of the same gender or a person who is transgender. C. Nothing in this section shall prevent a defendant from raising other recognized affirmative defense." (NMSA 30-1-16)

Self-defense and justification are separate questions; see New Mexico self-defense laws.

Involuntary manslaughter and the mental state

Involuntary manslaughter has two branches in 30-2-3(B): a killing "in the commission of an unlawful act not amounting to felony," and a killing "in the commission of a lawful act which might produce death in an unlawful manner or without due caution and circumspection."

New Mexico's Criminal Code does not define "recklessly" or "criminal negligence" in its general definitions section (30-1-12), so the mental state for involuntary manslaughter comes from case law. In a nonprecedential January 2026 decision, State v. Hubbard, No. S-1-SC-40649, the Supreme Court of New Mexico, quoting its earlier decision in State v. Henley, 2010-NMSC-039, stated that the required mens rea for an involuntary manslaughter conviction includes "recklessness, [by] which a defendant consciously disregards a substantial and unjustifiable risk that harm will result from his conduct."

Homicide by vehicle: New Mexico's vehicular manslaughter and DWI death law

New Mexico does not use the names vehicular manslaughter or DUI manslaughter. Under 66-8-101(A), "Homicide by vehicle is the killing of a human being in the unlawful operation of a motor vehicle." The grade depends on how the vehicle was operated.

Under the influence. "A person who commits homicide by vehicle while under the influence of intoxicating liquor or while under the influence of any drug is guilty of a second degree felony and shall be sentenced pursuant to the provisions of Section 31-18-15 NMSA 1978" (66-8-101(C)). Laws 2016, ch. 16 raised this form from a third degree to a second degree felony.

Prior DWI convictions. Under 66-8-101(F), a person who commits homicide by vehicle or great bodily harm by vehicle while under the influence, and "who has incurred a prior DWI conviction within ten years of the occurrence for which the person is being sentenced under this section shall have the person's basic sentence increased by four years for each prior DWI conviction."

Reckless driving. A person who commits homicide by vehicle while violating the reckless driving statute, 66-8-113, is guilty of a third degree felony (66-8-101(D)). The statute adds that a violation of the speeding laws "shall not per se be a basis for violation of Section 66-8-113." Reckless driving itself means driving "carelessly and heedlessly in willful or wanton disregard of the rights or safety of others and without due caution and circumspection and at a speed or in a manner so as to endanger or be likely to endanger any person or property" (66-8-113(A)).

Fleeing an officer. Under 66-8-101(H), a person who willfully operates a motor vehicle in violation of 30-22-1(C) "and directly or indirectly causes the death of or great bodily harm to a human being is guilty of a third degree felony."

The same section makes great bodily harm by vehicle, an injury rather than a death, a third degree felony when the driver is under the influence or driving recklessly (66-8-101(E)). Leaving the scene. A driver involved in an accident resulting in injury to or death of any person must immediately stop and remain at the scene until the requirements of 66-7-203 are fulfilled (66-7-201(A)). Failing to stop or comply where the accident results in great bodily harm or death is a fourth degree felony, or a third degree felony if done knowingly (66-7-201(B), (C)), and the director must revoke the person's licence (66-7-201(E)). For more on a driver's duties after a crash, see New Mexico hit-and-run laws. For DWI penalties where no one dies, see New Mexico DUI laws.

Other homicide offenses below murder

Assisting suicide. "Assisting suicide consists of deliberately aiding another in the taking of the person's own life, unless the person aiding another in the taking of the person's own life is a person acting in accordance with the provisions of the End-of-Life Options Act." It is a fourth degree felony (30-2-4), a separate offense from manslaughter.

Unborn child. New Mexico's homicide statutes apply to a "human being"; the death of a fetus is graded through two injury offenses. Injury to pregnant woman (30-3-7) is a person other than the woman injuring a pregnant woman in the commission of a felony, causing her to suffer a miscarriage or stillbirth, and is a third degree felony. Injury to pregnant woman by vehicle (66-8-101.1) is the same result caused in the unlawful operation of a motor vehicle; it is a third degree felony when the driver is under the influence of intoxicating liquor or any drug or is violating the reckless driving statute, 66-8-113. Both statutes define "stillbirth" as the death of a fetus before complete expulsion or extraction from its mother, irrespective of the duration of pregnancy, and exclude an induced abortion.

Drug deaths. The homicide article of the Criminal Code, 30-2-1 through 30-2-9, contains no separate offense for causing a death by distributing a controlled substance.

Other offenses graded by a resulting death.

• Negligent abuse of a child resulting in the child's death, 30-6-1(F): first degree felony.
• Intentional abuse of a child 12 to 18 resulting in the child's death, 30-6-1(G): first degree felony; of a child under 12, 30-6-1(H): first degree felony resulting in the death of a child (basic sentence of life imprisonment under 31-18-15).
• Abandonment of a child resulting in the child's death or great bodily harm, 30-6-1(B): second degree felony.
• Abuse or neglect of a care facility resident resulting in the resident's death, 30-47-4(D), 30-47-5(D): second degree felony.

Sentencing rules that affect manslaughter cases

• Alteration of the basic sentence. The judge decides the amount of any increase or decrease for aggravating or mitigating circumstances, but "in no case shall the alteration exceed one-third of the basic sentence," except that the judge may reduce by more than one-third for a serious youthful offender or youthful offender (31-18-15.1(G)).
• Habitual offenders. A person convicted of a noncapital felony with one prior felony conviction has the basic sentence increased by one year; with two priors, by four years; with three or more, by eight years (31-18-17).
• Earned meritorious deductions. Under 33-2-34, voluntary manslaughter is always a "serious violent offense," and a prisoner confined for a serious violent offense may receive no more than four days per month of meritorious deductions, compared with up to thirty days per month for a nonviolent offense (33-2-34(C)). Involuntary manslaughter and homicide by vehicle count as serious violent offenses only "when the nature of the offense and the resulting harm are such that the court judges the crime to be a serious violent offense."
• Probation. When a district court defers or suspends a sentence, the total period of probation may not exceed five years, and a defendant is automatically released from probation after completing at least half of it if classified as minimum risk by a validated scoring instrument and all probation obligations are met (31-20-5(A), (C)).

Recent changes

• 2025: Laws 2025, ch. 29 (HB 102), effective June 20, 2025, removed the words "third degree" before "homicide by vehicle" in the serious-violent-offense list of 33-2-34. Before that change only third degree homicide by vehicle was on the list; since then a court may judge any homicide by vehicle, including the second degree DWI form, to be a serious violent offense.
• 2025: Laws 2025, ch. 79 (SB 375), effective June 20, 2025, added the automatic-release rule to the probation statute, 31-20-5(C).
• 2022: Laws 2022, ch. 56 added the panic defense ban, 30-1-16, effective May 18, 2022.
• 2016: Laws 2016, ch. 16 made homicide by vehicle while under the influence a second degree felony (it had been a third degree felony).

Federal manslaughter

Federal law, 18 U.S.C. 1112, separately defines manslaughter for killings within the special maritime and territorial jurisdiction of the United States; our manslaughter laws hub covers it.

Related

• Manslaughter laws by state
• New Mexico felony and misdemeanor classes
• New Mexico DUI laws
• New Mexico hit-and-run laws
• The difference between murder, homicide and manslaughter
• Arizona manslaughter laws

This article provides general legal information about New Mexico law as of 2026-10-17. It is not legal advice. For a specific situation, contact a lawyer licensed in New Mexico.

Last updated: 2026-10-17.

Frequently Asked Questions

Is manslaughter a felony in New Mexico?

Yes. Voluntary manslaughter is a third degree felony resulting in the death of a human being and involuntary manslaughter is a fourth degree felony (NMSA 30-2-3). Homicide by vehicle is a second or third degree felony depending on its form (66-8-101).

How much time is voluntary manslaughter in New Mexico?

The basic sentence for a third degree felony resulting in the death of a human being is 6 years (31-18-15). The judge may alter it by no more than one-third for aggravating or mitigating circumstances (31-18-15.1(G)), and habitual-offender enhancements of 1, 4 or 8 years apply for one, two, or three or more prior felony convictions (31-18-17).

How much time is involuntary manslaughter in New Mexico?

Involuntary manslaughter is a fourth degree felony with a basic sentence of 18 months under 31-18-15, subject to the same one-third alteration limit and habitual-offender enhancements.

What is the difference between voluntary and involuntary manslaughter in New Mexico?

Both are unlawful killings without malice (30-2-3). Voluntary manslaughter is committed upon a sudden quarrel or in the heat of passion; involuntary manslaughter is committed in an unlawful act not amounting to a felony, or in a lawful act which might produce death done in an unlawful manner or without due caution and circumspection.

What is the charge for a DWI death in New Mexico?

Homicide by vehicle while under the influence of intoxicating liquor or any drug, a second degree felony sentenced under 31-18-15 (66-8-101(C)). The basic sentence increases by four years for each prior DWI conviction within ten years of the occurrence (66-8-101(F)).

Is speeding enough for homicide by vehicle in New Mexico?

The reckless driving form requires a violation of 66-8-113, and 66-8-101(D) provides that violating the speeding laws shall not per se be a basis for a reckless driving violation. Reckless driving means driving carelessly and heedlessly in willful or wanton disregard of the rights or safety of others.

Does New Mexico ban the gay or trans panic defense?

Yes. Since 2022, NMSA 30-1-16 provides that it is not a defense, justification or excuse in a criminal proceeding that the conduct was a reaction to the discovery of, knowledge about or potential disclosure of a victim's or witness's actual or perceived gender, gender expression, gender identity or sexual orientation, or that the defendant was romantically propositioned in a nonviolent or non-threatening manner by a person of the same gender or a transgender person.