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 Maryland, manslaughter is indeed categorized as either voluntary or involuntary, aligning with the general distinction made in many states. Voluntary manslaughter occurs when someone kills another person in the heat of passion or during a sudden quarrel without premeditation. It is treated as a felony and can result in significant prison time. Involuntary manslaughter in Maryland occurs when a person's negligent or reckless behavior leads to the death of another, such as in cases of vehicular manslaughter where the driver is intoxicated. This is also a felony and can lead to severe penalties. Maryland law does not require malice aforethought for manslaughter, distinguishing it from murder charges. The specific statutes detailing manslaughter offenses and penalties can be found in Maryland's criminal law code, and the penalties upon conviction can vary based on the circumstances and presence of any aggravating factors.