Involuntary manslaughter is the unlawful killing of another human being without intent. The absence of the intent element is the essential difference between voluntary and involuntary manslaughter. Also in most states, involuntary manslaughter does not result from a heat of passion but from an improper use of reasonable care or skill while in the commission of a lawful act or while in the commission of an unlawful act not amounting to a felony.
Generally there are two types of involuntary manslaughter: (1) criminal-negligence manslaughter; and (2) unlawful-act manslaughter. The first occurs when death results from a high degree of NEGLIGENCE or recklessness, and the second occurs when death is caused by one who commits or attempts to commit an unlawful act, usually a misdemeanor.
Although all jurisdictions punish involuntary manslaughter, the statutes vary somewhat. In some states, the criminal negligence type of manslaughter is described as gross negligence or culpable negligence. Others divide the entire offense of manslaughter into degrees, with voluntary manslaughter constituting a more serious offense and carrying a heavier penalty than involuntary manslaughter.
Many statutes do not define the offense or define it vaguely in common-law terms. There are, however, a small number of modern statutes that are more specific. Under one such statute, the offense is defined as the commission of a lawful act without proper caution or requisite skill, in which one unguardedly or undesignedly kills another or the commission of an unlawful act that is not felonious or tends to inflict great bodily harm.
Criminally Negligent Manslaughter A homicide resulting from the taking of an unreasonable and high degree of risk is usually considered criminally negligent manslaughter. Jurisdictions are divided on the question of whether the defendant must be aware of the risk. Modern criminal codes generally require a consciousness of risk, although, under some codes, the absence of this element makes the offense a less serious homicide.
There are numerous cases in which an omission to act or a failure to perform a duty constitutes criminally negligent manslaughter. The existence of a duty is essential. Since the law does not recognize that an ordinary person has a duty to aid or rescue another in distress, an ensuing death from failure to act would not be manslaughter. On the other hand, an omission in which one has a duty, such as the failure of a lifeguard to attempt to save a drowning person, might constitute the offense.
When the failure to act is reckless or negligent, and not intentional, it is usually manslaughter. If the omission is intentional and death is likely or substantially likely to result, the offense might be murder. When an intent to kill, recklessness, and negligence are present, no offense is committed.
In many jurisdictions, death that results from the operation of a vehicle in a criminally negligent manner is punishable as a separate offense. Usually it is considered a less severe crime than involuntary manslaughter. Although criminal negligence is an element, it is generally not the same degree of negligence as that which is required for involuntary manslaughter. For example, some vehicular homicide statutes have been construed to require only ordinary negligence while, in a majority of jurisdictions, a greater degree of negligence is required for involuntary manslaughter.
Unlawful-Act Manslaughter In many states, unlawful-act manslaughter is committed when death results from an act that is likely to cause death or serious physical harm to another person. In a majority of jurisdictions, however, the offense is committed when death occurs during the commission or attempted commission of a misdemeanor.
In some states, a distinction is made between conduct that is malum in se, bad in itself and conduct that is malum prohibitum, bad because prohibited by law. In these states, the act that causes the death must be malum in se and a felony in order for the offense to constitute manslaughter. If the act is malum prohibitum, there is no manslaughter unless it was foreseeable that death would be a direct result of the act. In other states that similarly divide the offense, the crime is committed even though the act was malum prohibitum and a misdemeanor, especially if the unlawful act was in violation of a statute that was intended to prevent injury to other persons.