Open Fields Doctrine
OPEN FIELDS DOCTRINE
the fourth amendment protects "persons, houses, papers, and effects against unreasonable searches and seizures." The amendment, held to embody a right of privacy, shelters certain enclaves from arbitrary government examination and interference. Within these enclaves, roughly defined as places where persons have a subjective expectation of privacy that society recognizes as reasonable—the paradigmatic case is the home—governmental searches and seizures are unreasonable unless authorized by a search warrant issued on probable cause. There are some exceptions to this rule against warrantless searches, however, and the open fields doctrine presents one of them.
In applying the Fourth Amendment to detached dwellings the Supreme Court has held that persons have a reasonable expectation of privacy in the home and its "curtilage." Curtilage is the area immediately surrounding the home that harbors the intimate activities associated with domestic life and home privacies. Proximity to the home, containment within an enclosure surrounding the home, use for domestic and private purposes, and steps taken to protect the area from observation all help to define its ambit.
The open fields doctrine permits warrantless searches of private land outside the curtilage. The right of privacy that the Fourth Amendment protects is therefore not congruent with the right of property ownership, and exercise of the common law right to exclude persons from land cannot make governmental searches of it unlawful. Further, under the doctrine open fields need be neither open nor fields, but only areas of land outside the curtilage. Fenced dense woods could therefore qualify as open fields. Consequently, neither the natural seclusion of property, which might be thought to make it private, nor efforts to keep trespassers out, such as posting with signs or surrounding with fences, secures it from governmental search.
(see also: Plain View Doctrine.)