Difference between Voluntary and Involuntary manslaughter

While manslaughter always refers to an act of killing, there is a distinct legal difference between voluntary and involuntary manslaughter. This article will help explain that difference.


Involuntary manslaughter

Involuntary manslaughter is the unlawful killing of a human being, done by accident, or through negligence, or reckless conduct. Manslaughter is involuntary when there is no intention to kill another human being. However, a condition for involuntary manslaughter is when, despite not intending to kill anyone, the person charged knows that their behavior is dangerous or reckless, and may endanger lives. There are two categories of involuntary manslaughter: criminal negligent manslaughter and unlawful act manslaughter. Manslaughter is criminally negligent when there is a high level of recklessness.  Manslaughter is classified as unlawful act when the person committing the act is breaking the law to do so.

A good example of this is a drunk driver who kills a pedestrian. Even though the drunk driver did not set out with the intention to kill another human being, he did. The driver ought to have known that operating a motor vehicle could cause danger to others, and that alcohol would make this activity more reckless. The drunk driver is committing an unlawful act manslaughter because he is driving under the influence of alcohol. Suppose that the driver was not drunk but killed a pedestrian because he was not paying attention to his driving. He would then be committing criminally negligent manslaughter.

Voluntary manslaughter

Voluntary manslaughter is the unlawful killing of a human being but with some level of prior motivation. It is not murder, however, because there is no premeditation involved. Voluntary manslaughter is often referred to as a killing of passion, or a heat-of-passion/heat-of-the-moment killing. The person charged with voluntary manslaughter committed the act knowing that their actions would harm another human being, but did not plan to commit this act.

A good example of this would be two men who get into a fight at a bar. Suppose that Man A provokes Man B with insults, and Man B attacks and kills him as a result. Man B knew attacking Man A would hurt and possibly kill Man A, but did not have a premeditated intention to murder Man A.

Comparison chart

Voluntary manslaughter Involuntary manslaughter
Intention in the moment. No intention in the moment.
Person committing the act knew their action would harm or kill and did it anyways. Person committing the act did not intend to hurt or kill anyone.

Involuntary vs voluntary manslaughter

What is the difference between involuntary and voluntary manslaughter? The main difference is whether or not there was intention during the act of killing itself.

Both involuntary and voluntary manslaughter are obviously acts of killing. When manslaughter is involuntary, there is no intention in the moment to kill another human being. When manslaughter is voluntary, intention to hurt or kill another human being is present, but there was no premeditation: the intention is only in the moment. Let us return to the two examples above. The drunk driver example is involuntary because the motorist did not intend to kill the pedestrian. The bar example is voluntary because Man B made a decision to hurt Man A in that moment, knowing that that harm could potentially kill Man A.


Below are two videos on voluntary and involuntary manslaughter.