A castle doctrine, also known as a castle law or a defense of habitation law, is a legal doctrine that designates a person's abode or any legally occupied place (for example, an automobile or a home) as a place in which that person has protections and immunities permitting one, in certain circumstances, to use force (up to and including deadly force) to defend oneself against an intruder, free from legal prosecution for the consequences of the force used. The term is most commonly used in the United States, though many other countries invoke comparable principles in their laws.
Depending on the location, a person may have a duty to retreat to avoid violence if one can reasonably do so. Castle doctrines lessen the duty to retreat when an individual is assaulted within one's own home. Deadly force may either be justified, the burdens of production and proof for charges impeded, or an affirmative defense against criminal homicide applicable, in cases "when the actor reasonably fears imminent peril of death or serious bodily harm to him or herself or another." A justifiable homicide that occurs within the home is distinct as a matter of law from castle doctrine, because the mere occurrence of trespassing—and occasionally a subjective requirement of fear—is sufficient to invoke the castle doctrine, under which the burden of proof of fact is much less challenging than that of justifying homicide in self-defense. However, the existence in a legal code of such a provision (of justifiable homicide in self-defense pertaining to one's domicile) does not imply the creation of a castle doctrine protecting the estate and exonerating any duty to retreat. The use of this legal principle in the United States has been controversial in relation to a number of cases in which it has been invoked, including the deaths of Japanese exchange student Yoshihiro Hattori and Scottish businessman Andrew de Vries.
History
The legal concept of the inviolability of the home has been known in Western civilization since the age of the Roman Republic. In English common law the term is derived from the dictum that "an Englishman's home is his castle" (see Semayne's case). This concept was established as English law by the 17th century jurist Sir Edward Coke, in his The Institutes of the Laws of England, 1628: