Trespass Was Not Search

The open fields doctrine excludes private land from the scope of Fourth Amendment protection: officials may enter and search there freely, but to do so in the home and its curtilage, they need a warrant. The century-old doctrine, proclaimed in Hester v. United States, is now being attacked by scholars as well as state courts—in July 2026, the Pennsylvania Supreme Court held that the “possessions” protected by the state constitution against unreasonable searches and seizures include land. The entire case against open fields rests on the single premise that because open land was protected by trespass law at the Founding, it was protected against “searches” as well. That premise derives from a handful of passages of Blackstone and has never been evaluated against the sources that magistrates relied on for searches in practice.

This Article shows that the critics’ premise is false. Trespass and search were separate bodies of law. Whereas trespass, which describes a private wrong, reached all land, search warrants were issued only for persons, houses, and goods. An original census of more than seven hundred printed warrant forms, drawn from one hundred thirty-five editions and printings of thirty-six justice-of-the-peace manuals from 1618 to 1791, shows that not one authorized a search of open land. Practice agrees, as in the eighty-two surviving colonial warrants and search orders examined here, land appears only once, and even there the conferral of search powers is limited to the house and “Chests, trunks, packs, or other Lock’d & barred Places.” Throughout, “possessions,” on which term the state cases hinge, meant goods, not land. The common law did protect open land, just not through the law of search, which is why Hester is historically sound. Beyond open fields, the trespass test Jones purported to revive rests on bad history. At common law, trespass was not search.