Idaho Manslaughter Laws: Voluntary, Involuntary and Vehicular (2026)

Idaho has one manslaughter statute with three kinds: under Idaho Code 18-4006, manslaughter is "the unlawful killing of a human being including, but not limited to, a human embryo or fetus, without malice," committed either voluntarily, involuntarily or in the operation of a motor vehicle. Voluntary manslaughter carries up to 15 years and involuntary manslaughter up to 10 years (18-4007), and vehicular manslaughter ranges from a misdemeanor to a felony with a 10-year mandatory minimum fixed term for a repeat DUI offender.

For the rules in 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 Idaho statutes on homicide below murder: manslaughter and its three kinds (Idaho Code 18-4006), the manslaughter penalties (18-4007), drug-induced homicide (37-2734D), excusable homicide (18-4012), and related sentencing and driving statutes. It does not cover murder sentencing (see how long a life sentence is in Idaho and our overview of murder sentencing guidelines), self-defense (see Idaho self-defense laws), civil lawsuits by surviving family (see Idaho wrongful death law), abortion law, or federal offenses, which the manslaughter laws hub covers.

What is manslaughter in Idaho?

The full definition reads:

"Manslaughter is the unlawful killing of a human being including, but not limited to, a human embryo or fetus, without malice. It is of three (3) kinds: (1) Voluntary - upon a sudden quarrel or heat of passion. (2) Involuntary - in the perpetration of or attempt to perpetrate any unlawful act, other than those acts specified in section 18-4003 (d), Idaho Code; or in the commission of a lawful act which might produce death, in an unlawful manner, or without due caution and circumspection; or in the operation of any firearm or deadly weapon in a reckless, careless or negligent manner which produces death. (3) Vehicular - in which the operation of a motor vehicle is a significant cause contributing to the death because of: (a) The commission of an unlawful act, not amounting to a felony, with gross negligence; or (b) The commission of a violation of section 18-8004 or 18-8006, Idaho Code; or (c) The commission of an unlawful act, not amounting to a felony, without gross negligence." Idaho Code 18-4006

Three features of the text matter.

No degrees. Idaho does not number its manslaughter offenses. The three kinds sit in one section, and the penalty for each is set separately in 18-4007.

Without malice. Malice is what separates manslaughter from murder, which Idaho defines as an unlawful killing "with malice aforethought" (18-4001).

Embryo or fetus. Both the manslaughter and murder definitions include "a human embryo or fetus." Idaho's homicide chapter has no separate fetal-homicide offense; the unborn victim is covered within these definitions. Idaho Code 18-4016 defines an embryo or fetus as "any human in utero" and provides that the homicide chapter does not permit prosecution of any person for conduct relating to an abortion with the consent of the pregnant woman (or consent implied by law), of any person for medical treatment of the pregnant woman or her embryo or fetus, or of the woman herself with respect to her embryo or fetus. Idaho's abortion statutes (Title 18, chapter 6) are separate and are not covered here.

Idaho manslaughter and homicide offenses at a glance

Idaho does not sort its crimes into felony classes. Each statute sets its own range, and Idaho Code 18-111 supplies the dividing line: "A felony is a crime which is punishable with death or by imprisonment in the state prison," and "Every other crime is a misdemeanor." The same section adds that a crime punishable by state prison that is also punishable by a fine or county jail "shall be deemed a misdemeanor for all purposes after a judgment imposing a punishment other than imprisonment in the state prison." Our guide to how Idaho sorts felonies and misdemeanors explains the rest of the system.

Is manslaughter a felony in Idaho, and what is the sentence?

Voluntary manslaughter, involuntary manslaughter and the first two forms of vehicular manslaughter are felonies, because each is punishable by a sentence to the custody of the state board of correction. Where a fine alone is also available, 18-111 deems the crime a misdemeanor after a judgment imposing a punishment other than state prison. The third form of vehicular manslaughter, 18-4006(3)(c), is a misdemeanor punishable by a jail sentence.

The ranges in 18-4007 are maximums:

• Voluntary: "a fine of not more than fifteen thousand dollars ($15,000), or by a sentence to the custody of the state board of correction not exceeding fifteen (15) years, or by both."
• Involuntary: "a fine of not more than ten thousand dollars ($10,000), or by a sentence to the custody of the state board of correction not exceeding ten (10) years, or by both."
• Vehicular: the tiers in the table above, discussed in the vehicular section below.

Weapon enhancement

Under Idaho Code 19-2520, a person convicted of manslaughter under 18-4006 "who displayed, used, threatened, or attempted to use a firearm or other deadly weapon while committing or attempting to commit the crime, shall be sentenced to an extended term of imprisonment." The extended term is computed "by increasing the maximum sentence authorized for the crime for which the person was convicted by fifteen (15) years."

Probation and withheld judgment

Idaho Code 19-2601 lets a district court, "in its discretion," commute a sentence to county jail, suspend execution of the judgment and place the defendant on probation, or withhold judgment, after a conviction or guilty plea to "any crime against the laws of the state, except those of treason or murder." Manslaughter is not on that exception list. Separately, the repeat-DUI tiers of vehicular manslaughter in 18-4007(3)(b)(ii)-(iii) call for a "mandatory minimum fixed term of imprisonment."

Voluntary and involuntary manslaughter in Idaho

Idaho uses the voluntary and involuntary labels in its statute.

Voluntary manslaughter is a killing without malice "upon a sudden quarrel or heat of passion" (18-4006(1)). The statute does not define adequate provocation or a cooling-off period.

Involuntary manslaughter has three routes (18-4006(2)):

• a killing in the perpetration of, or an attempt to perpetrate, an unlawful act, other than the acts specified in 18-4003(d);
• a killing in the commission of a lawful act that might produce death, done "in an unlawful manner, or without due caution and circumspection"; and
• a killing "in the operation of any firearm or deadly weapon in a reckless, careless or negligent manner which produces death."

Idaho's criminal code defines negligence in its general definitions: the words "negligence" and "negligently" "import a want of such attention to the nature of probable consequences of the act or omission as a prudent man ordinarily bestows in acting in his own concerns" (18-101(2)). Every crime requires "a union, or joint operation, of act and intent, or criminal negligence" (18-114).

Excusable homicide. The homicide chapter also describes when a killing is not a crime at all. Under 18-4012, homicide is excusable "When committed by accident and misfortune in doing any lawful act by lawful means, with usual and ordinary caution, and without any unlawful intent," and "When committed by accident and misfortune, in the heat of passion, upon any sudden and sufficient provocation, or upon a sudden combat when no undue advantage is taken nor any dangerous weapon used, and when the killing is not done in a cruel or unusual manner."

Can a killing be reduced from murder to manslaughter?

The statutory line is malice. A killing "with malice aforethought" is murder (18-4001); an unlawful killing "without malice" upon a sudden quarrel or heat of passion is voluntary manslaughter (18-4006(1)). Idaho's homicide chapter (Title 18, Chapter 40) contains no further definition of provocation and no provision addressing a gay or trans panic defense. Self-defense and justifiable homicide are covered on our Idaho self-defense laws page.

Vehicular manslaughter and DUI deaths in Idaho

Vehicular manslaughter is a kind of manslaughter under 18-4006(3), and every form requires that "the operation of a motor vehicle is a significant cause contributing to the death." The form depends on the reason the driving caused the death.

Gross negligence. An unlawful act not amounting to a felony, committed with gross negligence (18-4006(3)(a)), is a felony punishable by up to 10 years, a fine of up to $10,000, or both (18-4007(3)(a)). Section 18-4006 does not define gross negligence.

DUI or aggravated DUI. A death caused because of a violation of 18-8004 (driving under the influence) or 18-8006 (aggravated DUI) is vehicular manslaughter under 18-4006(3)(b). Idaho has no separately named DUI manslaughter offense; this is it. Section 18-4007(3)(b) grades it by the driver's prior DUI findings:

The prior-finding tiers are recent. Senate Bill 1099 (2025 Idaho Session Laws, chapter 171) amended 18-4007, according to its statement of purpose, "by addition of mandatory minimum sentence for an individual who has previously been found guilty of a violation of driving under the influence and is again found guilty of driving under the influence, along with vehicular manslaughter." Its emergency clause made the act effective "on and after July 1, 2025." The same act amended 18-8005 and 18-8006 to require the court to inform a defendant of certain information.

Without gross negligence. An unlawful act not amounting to a felony, committed without gross negligence (18-4006(3)(c)), is a misdemeanor punishable by up to 1 year in jail, a fine of up to $2,000, or both (18-4007(3)(c)). This form still requires fault. In State v. McNair, 141 Idaho 263, 108 P.3d 410 (Ct. App. 2005), the Idaho Court of Appeals held that negligence is an element of vehicular manslaughter under 18-4006(3)(c), concluding that "Idaho law requires a culpable mental state of at least simple negligence before an individual may be convicted of vehicular manslaughter."

The non-fatal companion. Aggravated DUI, causing "great bodily harm, permanent disability or permanent disfigurement" to another person while violating 18-8004(1)(a) or (1)(c), is a felony with a sentence "not to exceed fifteen (15) years" (18-8006(1)). For impaired-driving penalties when no one dies, see Idaho DUI laws.

License revocation. The Idaho Transportation Department "shall revoke the operating privilege of any driver upon receiving a record of the person's conviction" of vehicular manslaughter, "when the conviction has become final, if the court has not ordered the suspension or revocation of the privilege" (Idaho Code 49-325(1)(a)). The sentencing court may itself suspend the license of a person convicted of vehicular manslaughter "for a time determined by the court" (18-4007(3)(e)), and may order a person whose vehicular manslaughter caused the death of a parent of minor children to pay support for each child until the child reaches 18 (18-4007(3)(d)).

Leaving the scene and eluding police

Leaving the scene. A violation of Idaho Code 18-8007, leaving the scene of an accident resulting in injury or death, "shall constitute a felony and be punished by a fine of not more than five thousand dollars ($5,000) or by imprisonment in the state penitentiary for a period of not more than five (5) years, or by both," and the director of the transportation department "shall revoke for a period of one (1) year" the person's license (18-8007(2)-(3)). Our Idaho hit-and-run laws page covers the driver's duties.

Fleeing or attempting to elude a peace officer. The offense becomes a felony when the driver travels more than 30 miles per hour above the posted limit, causes damage to another's property or bodily injury to another, drives so as to endanger or be likely to endanger another's person or property, or leaves the state (Idaho Code 49-1404(2)). The section has no form graded by a resulting death.

Reckless driving. A first conviction is a misdemeanor punishable by up to 6 months in jail, a fine of up to $1,000, or both (Idaho Code 49-1401(2)).

Other homicide offenses below murder

Drug-induced homicide. Idaho added this offense in 2024 (2024 Idaho Session Laws, chapter 4). A person is guilty if the person "has violated the provisions of section 37-2732 (a), 37-2732B, or 37-2732D, Idaho Code, and has provided a controlled substance to a person," and "A person died as a result of the injection, inhalation, ingestion, or administration by any other means of any amount of such controlled substance" (Idaho Code 37-2734D(1)). It is "a felony punishable by imprisonment for an indeterminate term of life and a maximum fine of twenty-five thousand dollars ($25,000)" (37-2734D(2)).

Other offenses graded by a resulting death

• Injury to a child while transporting a child under the influence, Idaho Code 18-1501(3): if a child suffers bodily injury or death due to a violation of that subsection, it is a felony punishable by up to 10 years, "unless a more severe penalty is otherwise prescribed by law."
• Willfully or maliciously obstructing a railroad, causing a death, Idaho Code 18-6011: felony, not less than 5 years and up to life, or the person "may be tried and punished for murder."
• Causing or assisting a suicide, Idaho Code 18-4017: with the purpose of assisting another person's suicide or attempt, knowingly and intentionally providing the physical means or participating in a physical act by which the person commits or attempts it; felony, up to 5 years. The section excludes a health care professional relieving pain (unless acting to cause death) and withholding or withdrawing treatment under a living will, health care directive or similar document (18-4017(5)).
• A crime under the aircraft-damage chapter that results in a death, Idaho Code 21-703: the person is "subject also to imprisonment for life" at the jury's or court's discretion.

Related offenses graded by risk or injury rather than death:

• Abuse or neglect of a vulnerable adult under circumstances likely to produce great bodily harm or death, Idaho Code 18-1505(1): felony, up to 10 years and a $25,000 fine.
• Aggravated operation of a vessel under the influence, causing great bodily harm, permanent disability or permanent disfigurement, Idaho Code 67-7035(1): felony, up to 5 years.
• Operating a snowmobile, motorbike, utility type vehicle, specialty off-highway vehicle or all-terrain vehicle under the influence, Idaho Code 67-7114: misdemeanor.

Recent changes

• 2024: 2024 Idaho Session Laws, chapter 4 (House Bill 406), added drug-induced homicide, Idaho Code 37-2734D, alongside a fentanyl trafficking section (37-2732D).
• July 1, 2025: Senate Bill 1099 (2025 Idaho Session Laws, chapter 171) added the mandatory minimum fixed terms of 5 and 10 years in 18-4007(3)(b) for DUI-based vehicular manslaughter by a person with one or with two or more prior DUI findings. Offenses committed before that date fall under the earlier version of the section.
• 2025 and 2026 sessions: no other act amended 18-4006 or 18-4007.

Federal law, 18 U.S.C. 1112, separately covers manslaughter on federal land and in other federal jurisdictions; the manslaughter laws hub explains it.

Related pages

• Manslaughter laws by state
• Idaho felony and misdemeanor classes
• Idaho DUI laws
• Idaho hit-and-run laws
• The difference between murder, homicide and manslaughter
• Washington manslaughter laws
• Oregon manslaughter laws

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

Last updated: 2026-10-17.

Frequently Asked Questions

Is manslaughter a felony in Idaho?

Voluntary and involuntary manslaughter are felonies, as are the gross-negligence and DUI forms of vehicular manslaughter, because each is punishable by imprisonment in the state prison (Idaho Code 18-111, 18-4007); under 18-111, where a fine alone is also available, the crime is deemed a misdemeanor after a judgment imposing a punishment other than state prison. Vehicular manslaughter under 18-4006(3)(c), an unlawful act without gross negligence, is a misdemeanor of up to 1 year in jail.

What is the sentence for voluntary manslaughter in Idaho?

Up to 15 years, a fine of up to $15,000, or both (Idaho Code 18-4007(1)). If the person displayed, used, threatened or attempted to use a firearm or other deadly weapon, 19-2520 increases the maximum by 15 years.

What is the sentence for involuntary manslaughter in Idaho?

Up to 10 years, a fine of up to $10,000, or both (Idaho Code 18-4007(2)).

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

Both are unlawful killings without malice under 18-4006. Voluntary manslaughter is a killing upon a sudden quarrel or heat of passion; involuntary manslaughter is a killing in committing an unlawful act (other than those in 18-4003(d)), a lawful act done unlawfully or without due caution and circumspection, or reckless, careless or negligent use of a firearm or deadly weapon.

What is the penalty for DUI vehicular manslaughter in Idaho?

Under 18-4007(3)(b), up to 15 years and $15,000 for a person with no prior DUI finding; a mandatory minimum fixed term of 5 years, up to 25 years, after one prior; and a mandatory minimum fixed term of 10 years, up to 25 years, after two or more priors. The prior-finding tiers took effect July 1, 2025.

Can vehicular manslaughter be a misdemeanor in Idaho?

Yes. When the operation of a motor vehicle is a significant cause of a death because of an unlawful act not amounting to a felony, committed without gross negligence, it is a misdemeanor of up to 1 year in jail and $2,000 (18-4006(3)(c), 18-4007(3)(c)). State v. McNair (2005) held this form still requires at least simple negligence.

Is a drug overdose death a crime in Idaho?

Idaho Code 37-2734D makes it drug-induced homicide when a person who violated 37-2732(a), 37-2732B or 37-2732D provided a controlled substance to someone who died from it. It is a felony punishable by an indeterminate term of life and a fine of up to $25,000.

Does Idaho ban the gay or trans panic defense?

Idaho's homicide chapter contains no provision addressing it. Its only provocation language is the sudden quarrel or heat of passion clause in 18-4006(1) and the excusable-homicide clause in 18-4012.