Manslaughter is the unlawful killing or homicide of a human being without the premeditation or malice (malice aforethought) required for the criminal offense of murder. Many states have two types of manslaughter: (1) voluntary manslaughter—the defendant intended to kill the victim, but did so in self-defense, or in the heat of passion and without premeditation, or the defendant was insane and did not understand that the killing was wrong; and (2) involuntary manslaughter—the defendant negligently or recklessly caused the death of another person—such as when a person is intoxicated while operating a motor vehicle and causes an accident that results in the death of another person.

Some states do not have separate criminal offenses for voluntary and involuntary manslaughter—these states may have the offense of manslaughter and identify certain aggravating factors that may enhance the penalties upon a conviction for manslaughter. Manslaughter is a felony offense and may be punished by a lengthy prison term. Manslaughter laws are generally located in a state's statutes—often in the penal or criminal code.

In Wisconsin, manslaughter is not categorized as 'voluntary' or 'involuntary' but rather is addressed under the broader term of 'homicide.' Wisconsin statutes define different degrees of homicide based on intent, circumstances, and recklessness. First-degree reckless homicide (Wis. Stat. § 940.02) involves the reckless causing of the death of another human being under circumstances that show utter disregard for human life. Second-degree reckless homicide (Wis. Stat. § 940.06) involves causing death through reckless conduct but without the 'utter disregard for human life' element. Homicide by intoxicated use of a vehicle or firearm (Wis. Stat. § 940.09) is another relevant statute that addresses situations akin to what is commonly referred to as involuntary manslaughter in other jurisdictions, where the death is caused by the operation of a vehicle or handling of a firearm while intoxicated. Manslaughter in Wisconsin, under these various forms of homicide, is a felony offense and can result in significant prison terms, with the exact penalties varying based on the degree of the offense and the specific circumstances surrounding the incident.