The Fourth Amendment, ratified alongside the Fifth in 1791, protects "the right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures." It shares the same underlying constitutional value as the Takings Clause, security in one's property against arbitrary government interference, but it operates through an entirely different legal doctrine, one built around criminal investigations, warrants, and probable cause, not around condemning land for a public project.

The two amendments intersect at one specific, practical point: before formally condemning a property, government appraisers or engineers often need to enter the land to survey it, take soil samples, or assess its condition. Because that entry happens before any condemnation lawsuit has been filed, many states require either the owner's consent or a court order authorizing entry, echoing the Fourth Amendment's own consent-or-warrant framework even though the entry itself is usually governed by a state's own condemnation statute rather than the Fourth Amendment directly.

It is worth distinguishing eminent domain clearly from civil asset forfeiture, a separate and more controversial government power that lets law enforcement seize cash, vehicles, or other property suspected of being connected to a crime, sometimes without ever charging the owner. Forfeiture raises its own serious Fourth and Eighth Amendment concerns, but it is a different constitutional doctrine from eminent domain: forfeiture claims the property was itself connected to wrongdoing, while eminent domain compensates an owner precisely because their property was not accused of anything at all.