Deriving from the English common law dictum that “a man’s home is his castle,” the “Castle Doctrine” is an American legal doctrine generally allowing all manner of force, including deadly force, to protect the home, and its inhabitants.  Wisconsin’s version of the “Castle Doctrine” was signed into law by Governor Scott Walker on December 7, 2011. 

      Wisconsin’s “Castle Doctrine” immunizes persons who use force, including deadly force, in response to unlawful and forcible entry into a dwelling, motor vehicle, or place of business with civil liability immunity.  To become immunized, the person using force must “reasonably believe” that the force was necessary to prevent imminent death or bodily harm to himself or herself or to another person.  Under the new law, a person is usually presumed to have the required “reasonable belief” that the force was necessary.  Although the “Castle Doctrine” does not technically provide immunity purely for defense of property, as a practical matter, it will be hard to overcome the presumption when one decides to kill in defense of property. 

     In addition to the “reasonable belief,”  the “Castle Doctrine” requires that the person using (1) force know or reasonable believes that unlawful and forcible entry has occurred or that an unlawful and forcible entry is in the process of occurring; (2) that an unlawful and forcible entry actually has occurred or is in the process of occurring; and (3) where there has been an unlawful and forcible entry, the person using force must also be inside the entered home, vehicle or dwelling (where the entry is still occurring it is permissible to be outside, but on the property).  Public safety workers have some additional protection when they enter or attempt to enter in the performance of official duties, but only if they identified themselves before force was used or if the person using force knew or reasonably should have known that the person entering or attempting to enter was a public safety worker.  

     According to Wikipedia, Wisconsin is by no means the first state to adopt a Castle Doctrine.  However, Wisconsin’s law differs is some respects.  Unlike some states, Wisconsin does not require that the intruder intends to commit some felony in addition to the unlawful and forcible entry.  Wisconsin’s law does not contain a duty to retreat.  Finally, Wisconsin’s law immunizes the person who uses force instead of just creating a favorable presumption or defense.