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 Indiana, manslaughter is categorized under Indiana Code Title 35. Criminal Law and Procedure § 35-42-1. It is defined as the unlawful killing of a human being without malice aforethought, which distinguishes it from murder. Indiana recognizes both voluntary and involuntary manslaughter. Voluntary manslaughter (IC 35-42-1-3) occurs when someone intentionally kills another person while acting under sudden heat, which is a mitigating factor that reduces the offense from murder to manslaughter. Involuntary manslaughter (IC 35-42-1-4) involves the unintentional killing of another person due to reckless behavior, such as operating a vehicle while intoxicated. Manslaughter in Indiana is a felony offense and can result in significant prison time, with the exact penalties varying based on the circumstances of the offense and the presence of any aggravating factors.