In most jurisdictions, voluntary manslaughter consists of an intentional killing that is accompanied by additional circumstances that mitigate, but do not excuse, the killing. The most common type of voluntary manslaughter occurs when a defendant is provoked to commit the HOMICIDE. It is sometimes described as a heat of passion killing. In most cases, the provocation must induce rage or anger in the defendant, although some cases have held that fright, terror, or desperation will suffice.
If adequate provocation is established, a murder charge may be reduced to manslaughter. Generally there are four conditions that must be fulfilled to warrant the reduction: (1) the provocation must cause rage or fear in a reasonable person; (2) the defendant must have actually been provoked; (3) there should not be a time period between the provocation and the killing within which a reasonable person would cool off; and (4) the defendant should not have cooled off during that period.
Provocation is justifiable if a reasonable person under similar circumstances would be induced to act in the same manner as the defendant. It must be found that the degree of provocation was such that a reasonable person would lose self-control. In actual practice, there is no precise formula for determining reasonableness. It is a matter that is determined by the trier of fact, either the jury or the judge in a nonjury trial, after a full consideration of the evidence.
Certain forms of provocation that frequently arise have traditionally been considered reasonable or unreasonable by the courts. A killing that results from anger that is induced by a violent blow with a fist or weapon might constitute sufficient provocation, provided the accused did not incite the victim. It is not reasonable, however, to respond similarly to a light blow. A killing that results from mutual combat is often considered manslaughter, provided it was caused by the heat of passion aroused by the combat. An illegal arrest of one who knows of or believes in his or her innocence may provoke a reasonable person, although cases are in dispute on the issue of whether such an arrest would justify a killing. An attempt to make a legal arrest in an unlawful manner by the use of unnecessary violence might also constitute a heat of passion killing that will mitigate an intentional killing. Some cases have held that a reasonable belief that one's spouse is committing ADULTERY will suffice. An injury to persons in a close relationship to the accused, such as a spouse, child, or parent, is often held to constitute reasonable provocation, particularly when the injury occurs in the accused person's presence.
Mere words or gestures, although extremely offensive and insulting, have traditionally been viewed as insufficient provocation to reduce murder to manslaughter. There is, however, a modern trend in some courts to hold that words alone will suffice under certain circumstances, such as instances in which a present intent and ability to cause harm is demonstrated.
The reasonable person standard is generally applied in a purely objective manner. Unusual mental or physical characteristics are not taken into consideration. The fact that a defendant was more susceptible to provocation than an average person because he or she had a previous head injury is not relevant to a determination of whether the person's conduct was reasonable. There has, however, been a trend in some cases that indicates a willingness to consider some subjective factors.
If a reasonable period of time passed between the provocation and the killing so that the defendant had sufficient time to cool off, a homicide will not be reduced to manslaughter. Most courts will reduce the charge if a reasonable person would not have cooled off. Some, however, look solely at the defendant's temperament and make a subjective decision as to whether the person had sufficient time to regain self-control.
In some states, there is a case-law trend in which a killing that is committed under a mistaken belief that one is justified constitutes voluntary manslaughter. It is reasoned that although the crime is not justifiable, it is not serious enough to be murder.
It is a general rule that a defendant who acts in SELF-DEFENSE may only use force that is reasonably calculated to prevent harm to himself or herself. If the person honestly, but unreasonably, believes DEADLY FORCE is necessary and, therefore, causes another's death, some courts will consider the crime voluntary manslaughter. Similarly when a defendant acts under an honest but unreasonable belief that he or she has a right to kill another to prevent a felony, some courts will find the person guilty of voluntary manslaughter. Although it is generally considered a crime to kill another in order to save oneself, the justification of coercion or necessity may, likewise, reduce murder to manslaughter in some jurisdictions.