Physical Intrusion and the Home

Physical Intrusion and the Home

The privacy test taught in the last section is one way to establish a search, and the text of the Fourth Amendment supplies another. The Amendment protects the right of the people to be secure in their "persons, houses, papers, and effects" against unreasonable searches and seizures.¹ Those categories tie the guarantee to property, and for most of the Amendment's history courts understood it as a guard against government trespass on the things it lists.² The list also answers the problem that produced the Amendment. General warrants, such as the writs of assistance that gave customs officials blanket authority to search where they pleased, left the liberty of every person to the discretion of the individual officer, and the drafters responded by guaranteeing security in persons, houses, papers, and effects.³

It is easy to assume that Katz replaced that older rule, but the Court has made clear that Katz supplements it.⁴ In United States v. Jones agents attached a GPS tracking device to a vehicle and monitored its movements, and the majority held that installing the device was a search because the agents physically intruded on an effect to gather information, regardless of whether using the device also invaded a reasonable expectation of privacy.⁵ The consequence is that government conduct is a search if it satisfies either the trespass test or the privacy test, and a court that finds the trespass test met need not reach the privacy question, as the Jones majority did not.⁶ The property-based rule therefore works as a floor beneath Katz. Whatever the privacy test would say, entering a listed category to gather information remains a search, and the privacy test adds protection only where the floor does not reach.

The property route is often the simpler one when the home is involved. After Florida v. Jardines, a physical intrusion on persons, houses, papers, or effects is a search whether or not the person had a reasonable expectation of privacy in the place invaded.⁷ The privacy route requires a court to find an exhibited expectation and then to judge what society is prepared to recognize, and that second judgment offers no bright line. The property route asks a narrower question, whether officers physically entered or occupied one of the listed categories to gather information, and at the home that question is usually easy to answer because the home is "first among equals" among those categories.⁸ The Court's treatment of dwellings points the same direction. In Chapman v. United States it restated that a belief, however well founded, that evidence is inside a dwelling does not justify searching it without a warrant, since the decision whether privacy must yield belongs to a neutral magistrate and not to the officer pursuing the case.⁹ The exam trap is stopping at the privacy test when officers physically entered a house or its surroundings, because a weak privacy claim leaves the property route untouched.

Two limits on this route matter at the home. The route reaches only the enumerated categories, so the line between the house and the land around it decides many cases: the curtilage is treated as part of the house, while open fields beyond it are not, and officers who trespass on open fields have not conducted a search.¹⁰ The route also requires an intrusion the occupant has not permitted, so the question becomes what a visitor may do at a front door without exceeding the permission the public ordinarily has.¹¹ In Jardines the Court held that officers may approach a home's front door to knock like any private citizen, but that bringing a drug-sniffing dog to explore around the door exceeds that license and is a search.¹² The next two sections take these limits in order: first what counts as part of the home, then what a visitor, including an officer, may do there.

Curtilage as Part of the Home

The property-based route to a search reaches only the places and things the Amendment lists, which is why the line between the house and the land around it decides so many cases. The area immediately surrounding and associated with the home is called the curtilage, and the Court treats it as part of the home itself for Fourth Amendment purposes.¹⁴ That classification carries weight because the home ranks first among the listed categories. An officer who physically enters the curtilage to gather information has therefore intruded on a house, and a court can find a search without asking what the occupant expected about privacy.¹⁵ The front porch is the standard example. In Florida v. Jardines officers took a drug-sniffing dog onto the front porch of a house, and the Court held that the porch lay within the curtilage because it is the classic exemplar of an area adjacent to the home to which the activity of home life extends.¹⁶ The officers were gathering information there by entering and occupying the area in a way the homeowner had not permitted, which made the case a straightforward one.¹⁷

The reason for carrying the home's protection past its walls comes from what the Amendment guards at its core, the right to retreat into one's own home and be free there from unreasonable governmental intrusion.¹⁸ Home life does not stop at the front door. It extends to the porch, the patio, and the garden beside the house, and the Court has observed that the right to retreat would be of little practical value if agents could stand on the porch or in a side garden and trawl for evidence with impunity.¹⁹ The same right would shrink further if police could enter the property to watch a person's repose from just outside the front window. California v. Ciraolo makes the point from the other direction, describing the curtilage as an area intimately linked to the home, both physically and psychologically, where privacy expectations are most heightened.²⁰ The rule is also old. English judges first used the curtilage idea to extend burglary to the land near a dwelling, since those who enter it with felonious intent threaten the people inside, and the Framers likewise saw the need to shield land used for domestic activities that are intimately associated with the dwelling.²¹

Beyond the curtilage the protection ends. The Amendment names persons, houses, papers, and effects with some precision, so it does not forbid every investigation conducted on private property.²² Privately owned land outside the curtilage is called open fields, and an officer may, subject to the privacy test, gather information there because fields are not among the enumerated places.²³ The distinction between open fields and the house is as old as the common law, as the Court said in Hester v. United States.²⁴ In Oliver v. United States the Court applied that line to land the police entered by trespass and held that their entry and visual surveillance were not a search.²⁵ The difference rests on what happens on the land. Entries onto open fields do not threaten an area where domestic activities are taking place, while the curtilage is where those activities reach beyond the walls.²⁶

The pair shows which fact moves the answer: the location of the land relative to the house, and not who owns it. The exam trap is to let private ownership decide the question, because the Amendment's line runs around the home and its curtilage, and a privately owned pasture can be open fields while a few feet of patio is part of the house. The concept is workable because the boundaries of the curtilage are generally clearly marked and the idea is familiar from ordinary experience of homes.²⁷ Whether the occupant's permission reaches an officer who walks up to the porch is a separate question, taken up in the next section.

Curtilage status is also only the start of the analysis. In Ciraolo the area was a small yard immediately adjacent to a suburban home and enclosed by high double fences, and the Court accepted, as the State did, that the close nexus to the home placed the yard within the curtilage.²⁸ That status settled less than the homeowner hoped, because the Court went on to hold that curtilage status does not by itself bar all police observation, since the Amendment has never required officers to shield their eyes when passing a home on public thoroughfares.²⁹ The two cases involved the same kind of area and reached different results because the officers did different things. In Jardines they physically entered and occupied the curtilage, which satisfies the property route, while in Ciraolo they only looked from a public vantage point, which leaves the privacy route and its exposure-to-the-public limits, taken up later in this chapter.³⁰

The Implied License

The property route to a search depends on an intrusion the occupant has not permitted, so the question at a front door is what the occupant is treated as having allowed. Permission may be explicit or implied, and the implied kind does most of the work on a porch.³² The implied license comes from social custom: by ordinary habit, the occupant of a house with a path and a front door is understood to allow any visitor to walk up, knock, and wait a short time to be received.³³ Because the permission belongs to the public at large, an officer holds it on the same terms as a neighbor or a delivery driver, and officers may approach a home's front door to knock like any private citizen.³⁴ A porch visit of that kind is an entry onto the curtilage that the occupant is presumed to have licensed, which is why the approach alone is not a search.

A license reaches only as far as the custom that creates it, and that is where the rule does its work. The custom covers a visitor who wants to be received: approach, knock, wait briefly, and leave if no one answers.³⁵ No comparable custom invites a visitor to bring a trained animal to the door in order to investigate what the house contains, so conduct of that kind falls outside what the occupant is presumed to allow.³⁶ Once officers pass beyond the license, they stand where any other uninvited entrant stands, having occupied the curtilage to gather information, and the property route treats that entry as a search.³⁷ The license therefore has to be measured by the purpose and manner of the visit as well as by place. If it attached to the place alone, anyone with a lawful reason to stand on the porch could do anything there, and the protection of the home's surroundings would last only until an officer reached the front step.

In Florida v. Jardines police took a drug-sniffing dog to the front porch of a house, where the dog gave a positive alert for narcotics, and the officers used that alert to obtain a warrant whose execution turned up marijuana plants.³⁸ The Court held that the investigation was a search, because bringing a drug-sniffing dog to explore the area around the front door exceeds the implied license granted to the public and is a physical intrusion on the curtilage.³⁹ The walk up the path and the presence at the door were licensed. The exam trap is to label the approach as the intrusion; the conduct beyond the license is the dog's exploration of the porch. Nothing in the license depends on how strongly the officers suspect wrongdoing, since a visitor's permission is measured by what custom allows. A stronger tip therefore does not enlarge it, and a weaker one does not shrink it.

The lingering limit rests on the same custom as the rest of the license. The permission covers a visitor who waits briefly for an answer and then leaves, and presence at the door beyond that has no customary invitation behind it.⁴⁰ The two poles of the rule therefore differ in one fact, which is what the officers did once they reached the door. An officer who walks up the front path, knocks, and speaks with the occupant is doing what any private citizen may do and conducts no search, while detectives who bring a trained dog to the porch and let it explore the base of the door until it alerts have exceeded the license and have conducted one.⁴¹

A concurring opinion in Jardines reached the same result by the privacy route and observed that, at the home, property concepts and privacy concepts run mostly along the same path.⁴² It reasoned that a trained detection dog is a device not in general public use, that using such a device to explore details of a home the officers could not otherwise have learned without entering is a search under Kyllo v. United States, and that the objection that the device is just a dog does not change that analysis.⁴³ On an exam, the majority's route is the one to run first, with the privacy rationale available as a second basis. Why a dog's sniff of luggage or a car is treated differently is a separate question, taken up in the dog-sniff sections below.