“America inherited the Castle Doctrine from British common law. Put simply, the Castle Doctrine holds that “a man’s home is his castle”. But it springs from an older, much broader sentiment that the home should be protected as a place of refuge, peace and sanctuary. One of the earliest recorded pronouncements of the idea came from the Roman statesman Cicero: “What more sacred, what more strongly guarded by every holy feeling, than a man’s own home?” Implicit in the sentiment is not only the right to repel criminal intruders but also the idea that the state is permitted to violate the home’s sanctity only under limited circumstances, only as a last resort, and only under conditions that protect the threshold from unnecessary violence. Thus, before entering without permission, government agents much knock, announce and identify themselves, state their purpose, and give the occupants the opportunity to let them in peacefully. The Castle Doctrine establishes the home as a sanctum in which a citizen can expect to be let alone, a principle that the US Supreme Court justice Louis Brandeis called “the most comprehensive of rights, and the right most valued by civilized men.””
