Homicide is the act of one person causing the death of another person. Not all homicides are murder—some are manslaughter due to mitigating circumstances—and some are lawful when justified by an affirmative defense such as self-defense or insanity.

Criminal homicide generally involves (1) intent to cause death or serious bodily injury, or (2) negligence that causes the death of another person. Criminal homicide committed with the intent to cause death or serious bodily injury is generally charged as the criminal offense of murder (committed with intent and with premeditation or malice) or as voluntary manslaughter or second degree murder (committed with intent but without premeditation or malice).

And criminal homicide caused by negligence is generally charged as the criminal offense of involuntary manslaughter—for example, when a person is driving recklessly or speeding and hits another motor vehicle or pedestrian, causing the death of the other motorist or the pedestrian. A person driving a motor vehicle while intoxicated by drugs or alcohol who hits another motor vehicle or pedestrian, causing the death of the other motorist or the pedestrian, may be charged with involuntary manslaughter, or with a more specific offense like intoxication manslaughter or vehicular homicide—depending on applicable state laws.

Criminal homicide laws vary from state to state—including the names, degrees of severity, and punishments. These laws are generally found in a state’s statutes—often in the penal or criminal code.

In Idaho, homicide is defined as the killing of one person by another and can be classified into different categories based on the circumstances and the intent of the perpetrator. Murder, which is intentional and premeditated, is the most serious form of homicide and can be charged as first-degree murder under Idaho Code § 18-4003. Voluntary manslaughter, described in Idaho Code § 18-4006, occurs when a homicide is committed intentionally but without premeditation or malice aforethought, often in the heat of passion. Involuntary manslaughter, under Idaho Code § 18-4006(2) and (3), occurs when a person causes the death of another without intent but through negligence or unlawful acts that are not felonious or inherently dangerous. This can include deaths resulting from reckless driving or driving under the influence of drugs or alcohol. Idaho law also recognizes justifiable homicide, such as in cases of self-defense, and excusable homicide under specific circumstances outlined in Idaho Code § 18-4007 and § 18-4009. The specific charges and penalties for homicide offenses vary and are detailed in the Idaho Penal Code, with factors such as the perpetrator's intent, the presence of mitigating or aggravating circumstances, and the manner of death all playing a role in how a homicide case is prosecuted.