Manslaughter is the unlawful killing of another human being that occurs when a person kills another, without intent, malice, or forethought. In other words, the killing must have been without prior thought to do harm, or must have occurred “in the heat of passion.” Manslaughter is considered a less culpable crime than murder in most states. To explore this concept, consider the following manslaughter definition.

Definition of Manslaughter


  1. The unlawful killing of a person without malice or prior thought.


1250-1300        Middle English

What is Manslaughter

Manslaughter is the crime of killing a person without the intent, forethought, or reckless disregard for life that defines murder. Manslaughter is a serious crime, though the punishment is typically less serve than that for murder. The specific circumstances considered to be manslaughter may vary by state, and the crime is typically divided into three categories: voluntary manslaughter, involuntary manslaughter, and vehicular manslaughter.

Voluntary Manslaughter

Voluntary manslaughter takes place when the perpetrator intentionally kills the victim, though he had no prior plan or intent to kill. This crime is often referred to as killing in the “heat of passion.” In voluntary manslaughter, the circumstances leading to the killing are seen as to lead a reasonable person to become so emotionally disturbed that he would act in the heat of the moment. There are typically three defenses used to mitigate voluntary manslaughter:

  1. Provocation – refers to the reason the perpetrator killed the victim. Any provocation that would cause a reasonable person to lose control may be deemed “adequate,” or “reasonable,” provocation. Adequate provocation often marks the difference between voluntary manslaughter and murder.
  2. Imperfect Self-Defense – if a perpetrator acts, reasonably believing self-defense to be necessary, even if that belief was erroneous, the killing would be considered justified, and therefore voluntary manslaughter.
  3. Diminished Capacity. This defense refers to the metal state of mind when the killing occurred. In most states, when a person commits murder and the court finds evil intent was not in place due to a metal disability, the court will offer the defendant lesser charges.

Example of Voluntary Manslaughter

James comes home and finds his wife, Alice, in bed with another man. James is immediately heartbroken and angry. He picks up a golf club next to the bed and hits the man in the head. The man dies instantly. In ordinary circumstances, James would never kill another person, but he was so emotionally disturbed after finding his wife having an affair, he acted out of passion. Because James intentionally killed the man, but had no prior thought or intent to kill, he has committed voluntary manslaughter.

Punishment for Voluntary Manslaughter

The punishment for voluntary manslaughter varies depending on the jurisdiction, as well as the specific facts of the case. The punishments that may be handed down for voluntary manslaughter during the sentencing phase of the trial range from probation, fines, and community service, to incarceration in a state prison. In addition to the range of punishments dictated by law, the judge also considers other factors in determining sentencing.

Circumstances surrounding the manslaughter also have an effect on the exact length of time such as the brutality of the crime and the history of the defendant. These are known as “mitigating factors,” which are factors that decrease the severity of the crime, and “aggravating factors,” which are factors that increase the severity of the crime, and usually add to the sentence.

For example:

Jamal becomes enraged when he catches his girlfriend drinking and dancing with another man at the local nightclub. Jamal picks up a solid wooden chair and beats the man to death. In his state of California, Jamal faces 3 to 11 years in prison. During the sentencing phase of the trial, the judge considers the brutality of the crime, as Jamal continued beating the victim even after he was unconscious, or perhaps dead.

Additionally, Jamal has a prior conviction for felony domestic violence, in which a previous girlfriend was hospitalized for two weeks. These aggravating factors mean the judge is likely to sentence Jamal to the maximum of 11 years, rather than offering him a break with a shorter sentence.

Involuntary Manslaughter

The term involuntary manslaughter refers to the unintentional killing of a person that happens when the perpetrator is committing another minor crime, with no intent to kill, or is engaging in reckless behavior that caused the death. Involuntary manslaughter is differentiated from voluntary manslaughter, as there is an absence of intent to kill or cause harm to the victim. In most jurisdictions, there are two types of involuntary manslaughter, constructive and criminally negligent.

  • Constructive Manslaughter – also known as “misdemeanor manslaughter,” constructive manslaughter is the act of killing a person during the commission of an unlawful act. This usually applies when the death was caused as an unintentional consequence of the perpetrator’s actions in committing a minor crime.
  • Criminally Negligent Manslaughter – also known as “criminally negligent homicide,” refers to a death caused by the perpetrator’s serious negligence or reckless act. The degree of negligence required to subject the perpetrator to criminal charges is very high. Criminally negligent manslaughter may also apply when a person who has a duty to act in a certain manner fails to do so, causing the victim’s death.

Example of Involuntary Manslaughter

Bob has an argument with his wife, and ends up down at the bar drinking with his friends. Later that day, after drinking for hours, Bob gets into his car and attempts to drive home. During his drive, Bob swerves to the right and hits a man on a bicycle, killing him. Bob was committing a crime by driving under the influence of alcohol when he unintentionally killed the cyclist. He may be charged with involuntary manslaughter.

Defenses to Involuntary Manslaughter

To prove a defendant committed involuntary manslaughter, the prosecutor must prove that the victim’s death was directly caused by the defendant’s actions, or failure to act. A defense to involuntary manslaughter will typically cast doubt on whether the defendant knew that his act was dangerous, and presented a risk of causing death.

Punishments for Involuntary Manslaughter

Punishments for involuntary manslaughter vary by jurisdiction, both by state, and as a federal crime. In all jurisdictions, however, involuntary manslaughter is a felony, and the perpetrator faces a year or more in prison, as well as other punishments such as probation, fines, restitution, and community service. The perpetrator of this crime may also face civil penalties, as the victim’s family has the right to sue in civil court. In such a case, it is not necessary that the defendant be convicted, or even formally charged, for the civil lawsuit to occur.

An example of this is the famous O.J. Simpson case in which the former pro football player was tried for the murders of his ex-wife, Nicole Brown Simpson, and her friend, Ronald Lyle Goldman. Though Simpson was acquitted in the murder trial, the families of the victims filed a civil lawsuit against Simpson, and were ultimately awarded nearly $34 million in damages.

Vehicular Manslaughter

Also known as “vehicular homicide, vehicular manslaughter is defined as the killing of another while illegally, negligently, or recklessly operating a motor vehicle. Most people relate deaths caused by driving under the influence of alcohol or drugs to the term vehicular manslaughter. In truth, it has a much broader application. An individual who has caused someone’s death by driving in an illegal manner, recklessly, or without regard for the harm he may cause, may be charged with vehicular manslaughter.

In fact, before laws forbidding texting while driving, many prosecutors used the charge of vehicular manslaughter to prosecute defendants for killing someone because they were texting or otherwise paying attention to their phone rather than the road. Other applications of this charge include street racing and road rage incidents.

Example of Vehicular Manslaughter

Donald drives a truck for a major grocery supplier. He lied to his supervisor about when he unloaded, and accepted another load knowing he was too fatigued to drive. He falls asleep at the wheel and hits another car, killing the passenger. Donald is charged with vehicular manslaughter, as he did not intend to kill another person, but he acted negligently, choosing to drive with the knowledge that he should not have been behind the wheel.

Defenses to Vehicular Manslaughter

Because this crime is charged due to the defendant’s recklessness and disregard for the safety of others, there are not many viable defenses to vehicular manslaughter. There can be no claim of self defense, but the defendant may attempt to show that the victim’s death was not actually caused by his actions. This is referred to as “lack of causation.” Such a defense, even if not wholly successful, may mitigate the defendant’s liability, resulting in reduced charges, and a lighter sentence.

Punishments for Vehicular Manslaughter

Punishments for vehicular manslaughter range from imprisonment, restitution, and fines, to suspended sentences and probation. Imprisonment for as long as 20 years is a possibility in most jurisdictions, and the perpetrator may be ordered to participate in a drug or alcohol recovery program, and safe driving courses to be allowed to legally drive again.

In addition to whatever criminal punishment the judge may deem appropriate, the perpetrator may face a civil lawsuit filed by the victim’s family. If the family is successful in proving it is more likely than not that the defendant’s acts caused the victim’s death, the judge may award monetary damages for medical expenses incurred by the victim, property damages, and even the pain and suffering experienced by the family.

Related Legal Terms and Issues

  • Acquit – To relieve someone from a criminal charge; to declare not guilty.
  • Aggravating Factor – Any fact or circumstance that increases the severity or culpability of a criminal act.
  • Civil lawsuit – A lawsuit brought about in court when one person claims to have suffered a loss due to the actions of another person.
  • Criminal Charge – A formal accusation by a prosecuting authority that an individual has committed a crime.
  • Culpability – Guilt, blame, or responsibility for an act.
  • Damages – A monetary award in compensation for a financial loss, loss of or damage to personal or real property, or an injury.
  • Defendant – A party against whom a lawsuit has been filed in civil court, or who has been accused of, or charged with, a crime or offense.
  • Emotional Distress – A negative emotional reaction, such as anguish, humiliation, or grief, resulting from the conduct of another individual. Also referred to as “mental anguish.”
  • Intent – A resolve to perform an act for a specific purpose; a resolution to use a particular means to a specific end.
  • Jurisdiction – The legal authority to hear legal cases and make judgments; the geographical region of authority to enforce justice.
  • Lesser charge — A lesser charge, or included offense, shares some elements of the main charge or greater criminal offense. For example, trespassing is a lesser included offense of burglary, aggravated sexual assault is a lesser included offense of rape, and manslaughter is a lesser included offense of murder.
  • Malice – The intention to do evil, inflict injury, or cause suffering of another.
  • Mitigate – To lessen the intensity, force, or harshness; to moderate; to make less severe.
  • Negligence – Failure to exercise a degree of care that would be taken by another reasonable person in the same circumstances.
  • Trial – A formal presentation of evidence before a judge and jury for the purpose of determining guilt or innocence in a criminal case, or to make a determination in a civil matter.
  • Victim – A person who is injured, killed, or otherwise harmed as a result of a criminal act, accident, or other event.