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 New Hampshire, homicide is defined as the unlawful killing of one person by another. The state differentiates between murder, manslaughter, and negligent homicide. Murder is further classified into first and second degree. First-degree murder involves premeditated intent to kill, while second-degree murder involves reckless conduct with an awareness of a likely fatal outcome. Manslaughter in New Hampshire is usually considered a result of heat of passion or provocation and does not involve malice aforethought. Negligent homicide occurs when a person causes the death of another through criminal negligence, such as reckless driving or driving under the influence of drugs or alcohol. New Hampshire law also recognizes affirmative defenses like self-defense or insanity, which can justify or excuse the act. The specific charges and penalties for homicide offenses are detailed in the New Hampshire Revised Statutes Annotated (RSA), particularly in the sections pertaining to criminal offenses against the person.