The Castle Doctrine

Fundamentals of Criminal Law by Adam J. McKee

Defense of habitation is a defense that applies specifically to the defendant’s residence. Under the ancient common law, a person’s home was considered sacred, and deadly force could be employed to protect it. The majority of states have since enacted modern castle laws that embody this common-law doctrine.  

As with the doctrines of defense of property, self-defense, and defense of others, force is authorized by law when used to protect the home.  The primary difference is that most states authorize the use of deadly force, which blurs the usually bright line that authorizes deadly force only in answer to deadly force. Hence, discussions of the Castle Doctrine focus primarily on the use of deadly force.

The first state to expand the defense of habitation to include the use of deadly force was Colorado, with its “make my day” self-defense statute.  In 2005, Florida began a wave of castle law modifications that resulted in most states revising their defense of habitation laws. Broadly, three elements must be demonstrated before the use of deadly force is lawful under these modern castle laws.  First, the intruder must actually enter or be in the process of entering the residence owned by the defendant. The proper scope of the first element is not written in stone, and some states (e.g., Arkansas) have extended the protected area to the curtilage of the home.

Term of Art:  Curtilage

Excerpts from United States v. Dunn (1987):

The curtilage concept originated at common law to extend to the area immediately surrounding a dwelling house the same protection under the law of burglary as was afforded the house itself. The concept plays a part, however, in interpreting the reach of the Fourth Amendment. Hester v. United States, 265 U.S. 57, 59 (1924), held that the Fourth Amendment’s protection accorded “persons, houses, papers, and effects” did not extend to the open fields, the Court observing that the distinction between a person’s house and “open fields” is as old as the common law.

We [SCOTUS] recognized that the Fourth Amendment protects the curtilage of a house and that the extent of the curtilage is determined by factors that bear upon whether an individual reasonably may expect that the area in question should be treated as the home itself. We identified the central component of this inquiry as whether the area harbors the “intimate activity associated with the sanctity of a man’s home and the privacies of life.”  

…we believe that curtilage questions should be resolved with particular reference to four factors: the proximity of the area claimed to be curtilage to the home, whether the area is included within an enclosure surrounding the home, the nature of the uses to which the area is put, and the steps taken by the resident to protect the area from observation by people passing by.

Source:  United States v. Dunn, 480 U.S. 294 (1987).   Available:

Most states exclude intruders who are outside or in the curtilage.  Generally, the residence must be occupied when the entry occurs. This excludes devices like “spring guns” and “boobie traps” that protect unoccupied dwellings with deadly force.  In order for these statutes to pass Constitutional muster, the defendant must have an objectively reasonable belief that the intruder intends to commit a crime of violence against the occupants after entry.  

Model Penal Code:  The Use of Devices to Protect Property

(5) Use of Device to Protect Property.  The justification afforded by this Section extends to the use of a device for the purpose of protecting property only if:

(a) the device is not designed to cause or known to create a substantial risk of causing death or serious bodily harm;  and

(b) the use of the particular device to protect the property from entry or trespass is reasonable under the circumstances, as the actor believes them to be;  and

(c) the device is one customarily used for such a purpose or reasonable care is taken to make known to probable intruders the fact that it is used.

The majority of states have modified their castle laws to rescind any duty to retreat when inside the home. Florida’s castle law creates a presumption that the defendant has a reasonable fear of imminent peril of death or great bodily injury when the intruder makes an unlawful or forceful entry.  This compels the prosecution to disprove the defendant’s reasonable belief of death or great bodily injury beyond a reasonable doubt, which is extremely difficult. Additional considerations of many castle laws are civil immunity and criminal immunity from prosecution.

Term of Art:  Legal Immunity

Legal immunity has been defined as “a legal status wherein an individual or entity can not be held liable for a violation of the law to facilitate societal aims that outweigh the value of imposing liability in such cases. Such legal immunity may be from criminal prosecution or from civil liability (being subject of lawsuit) or both.”

Under the castle doctrine, immunity from prosecution means that a defendant who complies with the castle law requirements cannot be sued for damages or prosecuted for a crime based on injury or death to the intruder.


Modification History

File Created:  07/17/2018

Last Modified:  09/13/2023

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This work is licensed under an Open Educational Resource-Quality Master Source (OER-QMS) License.

Open Education Resource--Quality Master Source License


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