Rights of Passage: On Doors,Technology,and the Fourth Amendment

I. Introduction

The importance of the door for human civilization cannot be overstated. Across various times and cultures, the door has been a central technology for facilitating the distinction between inside and outside, individuals and society, private and public, and profane and sacred. According to some, the door was the medium that initially turned the hunter into a shepherd, thereby distinguishing man from animal. ² In his essay “Where are the Missing Masses,” ³ Bruno Latour traces the genealogy of door design. In his words: “Walls are a nice invention, but if there were no holes in them there would be no way to get in or out – they would be mausoleums or tombs … So architects invented this hybrid: a wall hole, often called a door, which although common enough has always struck me as a miracle of technology.” ⁴

The “thingness” of the door is intimately tied to that of the threshold: the liminal space that “belongs neither to the inside nor the outside and is thus an extremely dangerous space.” ⁵ According to anthropologist Arnold van Gennep: “To cross the threshold is to unite oneself with a new world. It is thus an important act in marriage, adoption, ordination, and funeral ceremonies.” ⁶ Drawing on van Gennep, Victor Turner coined the term liminality, which refers to the marginal (or “limen”) stage of transition whereby the subject of the passage ritual is invisible. In Turner’s words, “As members of society, most of us see only what we expect to see, and what we expect to see is what we are conditioned to see when we have learned the definitions and classifications of our culture.” ⁷ Along similar lines, sociologist Pierre Bourdieu says about the door of the traditional Berber house that:

During the summer the door of the house must remain open all day long so that the fertilizing light of the sun may enter, and with it prosperity. A closed door means penury and sterility: to sit down upon the threshold means, by obstructing it, to close the passage to happiness and plenitude. When one wishes prosperity to someone one says: “May your door remain open.” ⁸

Although in contemporary western cultures doors have seemingly been relieved of such rituals of passage and reduced to their straightforward materiality, the symbolic and even spiritual meanings assigned to the liminal space between “in” and “out” are still acutely relevant. The space of the door is, quite literally, a liminal space. Looking at how American courts have construed this space may thus help us understand how they conceive liminality more broadly. Furthermore, studying the legal geography of doors may contribute to a deeper understanding of other legal thresholds.

Despite its benign appearance, the door is never a neutral technology. Latour points out the various ways in which doors discriminate. The heavy hydraulic door, for example, discriminates against the very little and very old, as well as “against furniture removers and in general everyone with packages, which usually means, in our late capitalist society, working- or lower-middle-class employees.” ⁹ Hence, doors are not only an architectural medium; they are also “operators of symbolic, epistemic, and social processes that, with help from the difference between inside and outside, generate spheres of law, secrecy, and privacy and thereby articulate space in such a way that it becomes a carrier of cultural codes.” ¹⁰

Drawing on the insights of Science and Technology Studies (STS), this article will explore how the door matters in American Fourth Amendment jurisprudence. I will begin with a brief account of the importance of the home – into which the door provides both visual access (similar to a window) and an opportunity for bodily entry – in American criminal procedure. Next, I will discuss the spatiolegal rituals performed by the police, and the case law established by American courts, with regard to the door. In particular, I will focus on police searches and seizures that illuminate the door’s liminal legal geography. Finally, I will highlight law’s focus on vision, mainly in the context of the home but also with respect to cars.

In light of recent technological advancements that enhance the ability to literally see through walls, we might be witnessing the end of the physical door era and the beginning of a virtual door era. Currently, the courts seem to be operating as if the door still blocks view, but this may change as the technology presents increasingly sophisticated challenges to the distinctions between in and out, private and public, and legal and illegal visions. This is therefore an important moment for reflecting on what U.S. courts and American society at large believe is worthy of protection on the inside of the residential door.

Throughout the article I revisit Latour’s realization that, “To balance our accounts of society, we simply have to turn our exclusive attention from humans and look also at nonhumans.” ¹¹ My analysis here will show that the door’s meanings and materialities are, in fact, inseparable. The door, in other words, is both a symbol of sacred domesticity and a technology that possesses material agency. The door also provides an allegorical entry into a bizarre constitutional discourse whereby doors both embody and represent the relationship between the Government, on one side of the door, and the People, on the door’s other side.

II. The Home as One’s Castle

Law makes and unmakes the home.

—Jeannie Suk, “Taking the Home” ¹²

The home is conventionally described in legal discourse as a refuge or sanctuary, a fortress or castle, and a haven in a heartless world. ¹³ Even the “poorest man[’s] ruined tenement” ¹⁴ is afforded the same protections, including the ability to exclude the king from entering with impunity. ¹⁵ A man’s home is his “castle and fortress.” ¹⁶ The sanctity of the home is not a unique invention of American, or even English, law: it has been the nexus of certain protections as far back as the Code of Hammurabi ¹⁷ and descends from “the sentiments of ancient Rome.” ¹⁸ The direct antecedent to the American protections of the home are the protections afforded to eighteenth-century British landowners. Indeed, “The British state … existed to preserve the property and, incidentally, the lives and liberties, of the propertied.” ¹⁹

The home assumes a unique significance in modern liberal societies, where it provides a nest for individuality, family, privacy, security, and liberty. ²⁰ In the words of David Delaney: “In our world, it’s fair to say, the modern home is more specifically registered as the liberal home . . . Hence the interpretive and affective salience of the public/private distinction; hence the valorization of privacy, security, protection, and self-expression; hence the expression of these in the idioms of rights.” ²¹ The physical manifestation of the home as “the house” in particular occupies a central place in American legal traditions. Houses are mentioned explicitly in both the Third and Fourth Amendments ²² and implicitly in the First Amendment, ²³ indicating a clear concern for this space by the framers of the U.S. Constitution. ²⁴ The protections and importance of the house/home are recognized, additionally, in many other areas of the law. ²⁵

My central concern in this article is the hybrid legal geography of wall and hole (“door”) that serves as the “obligatory passage point” ²⁶ to the home and how this hybrid spatiolegal entity is interpreted in the context of Fourth Amendment protections. The Fourth Amendment establishes:

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized. ²⁷

The federal courts have been acutely sensitive to one’s reasonable expectation of privacy in the home. ²⁸ Until the monumental 1967 Supreme Court decision of Katz that incorporated the concept of privacy into the juridical analysis, ²⁹ the Court’s interpretation of the Fourth Amendment was concerned primarily with its tangible geographies, which it based on a finite list in the Constitution. The main threat to the house was, in other words, its physical invasion ³⁰ and the protected right was the “indefeasible right . . . of private property.” ³¹ Subsequent developments in Fourth Amendment jurisprudence maintain the same underlying logic of protecting the home from invasion. ³² Yet whereas some cases are concerned with physical bodily invasion by the state into the intimacies of the home – namely, with the function of the door as a technology that enables and disables a full bodily entry – other cases focus on the permissibility of governmental gazes into the home through the door – namely the door’s function as a window. Finally, the invention of technologies that enable seeing through walls without the use of doors (in their function as either door or window) has resulted in the configuration of doors in recent cases as symbolic matters, as indicators of an illegal invasion into the privacy of one’s home.

Despite the recent challenges to the physical invasion approach of the Fourth Amendment, the Supreme Court has clarified that the trespass test still applies in this context. ³³ “At the Amendment’s very core stands the right of a man to retreat into his own home and there be free from unreasonable governmental intrusion,” the Supreme Court Justices re-emphasized in their 2013 decision Florida v. Jardines. ³⁴ In another decision, the Justices clarified their position that: “The Fourth Amendment protects the individual’s privacy in a variety of settings. In none is the zone of privacy more clearly defined that when bounded by the unambiguous physical dimensions of an individual’s home.” ³⁵ In spite of the technological developments, then these and other cases characterize the protection of the home as a longstanding tradition and as a “monument of English freedom.” ³⁶ Perhaps the most far-reaching protection in this regard is the government’s lack of power to prosecute certain crimes when they occur exclusively within the home, including obscenity and sodomy. ³⁷

The various constitutional protections against invasion are not limited to governmental actions. In addition to the property right to exclude others, the Supreme Court has stated that there is no duty to retreat from attack “on [one’s] premises,” ³⁸ and many states ³⁹ have laws that afford defenses to citizens who use otherwise unacceptable force to defend the “sanctity of their homes.” ⁴⁰ This, again, is based on the assumption that a “man’s home is his castle” and that its dweller has a right to defend it against intrusion. ⁴¹ A similar logic is applied to protect a “man in his castle” from the exercise of First Amendment rights by others. ⁴² It is important to note in this context that feminist critiques of homes as virtual traps for victims of intimate violence have led to government entry into the home in the form of protection orders ⁴³ and, more recently, to feminist critiques of such orders. ⁴⁴

III. Delineating the Fourth Amendment Threshold

The critical importance of the home in American jurisprudence manifests in the designation of heightened protections to privacy, property, and liberty when those are exercised within the home. In the Fourth Amendment context, such enhanced protections against governmental (mostly police) intrusions have translated into the requirement that absent limited and pre-defined emergency situations (“exigency”), the police must obtain a warrant to legally enter a home. The warrant is a judicially reviewed authorization granted to governmental officials to search or seize; it must be supported by an affidavit from the relevant governmental official that outlines the specific facts and scope of the search and that establishes probable cause to believe that a crime has been, is being, or will be committed. Generally, a police invasion of the home without obtaining a valid warrant based on probable cause will render the seized evidence inadmissible in court. At least on the face of things, then, administrative obstacles inherently linked to the geography of police practices impose heightened scrutiny on such practices when they occur within the home. Demarcating where the outside ends and where the home begins is thus crucial for ascertaining the legal rights applicable in each case. The stakes of this demarcation are incredibly high: they determine the course of human lives, impelling them toward either freedom or incarceration.

The Supreme Court has long declared its intentions to come up with “bright line rules” in criminal procedure cases. In Payton v. New York (1980), ⁴⁵ the Supreme Court situated the bright line at the door to the house. The Court also acknowledged that this line could be thin or thick, depending on the circumstances. To accommodate this variability, the Court adopted the common law doctrine of the curtilage, which expands the house’s protections to the area immediately surrounding it. The Court, in other words, effectively expanded the house’s protections to the “intimate activity associated with the ‘sanctity of a man’s home and the privacies of life.’” ⁴⁶

United States v. Dunn (1987) provided additional guidance on how to determine the existence and boundaries of the curtilage. The Court instructed that: “curtilage questions should be resolved with particular reference to four factors: the proximity of the area claimed to be curtilage to the home, whether the area is included within an enclosure surrounding the home, the nature of the uses to which the area is put, and the steps taken by the resident to protect the area from observation by people passing by.” ⁴⁷ Through the curtilage doctrine, the door’s physical liminality and its function as an obligatory passage point has expanded to become one of an obligatory passage zone between outside (i.e., public, less protected) and inside (i.e., private, more protected) spaces. In Fourth Amendment jurisprudence, then, the threshold is not limited to its quintessential form – the door – but includes proximate spaces that have acquired the door’s liminal quality. Although not situated inside the house, these spaces still receive similarly heightened legal protections.

Alongside its acknowledgement that the bright line is not really a line but rather a zone that encompasses the curtilage, the Supreme Court also warned against case-by-case solutions that depend on “all sorts of ifs, ands, and buts” and that require “the drawing of subtle nuances and hairline distinctions.” ⁴⁸ Accordingly, in Oliver v. United States, ⁴⁹ the Court declared that “for most homes, the boundaries of the curtilage will be clearly marked” ⁵⁰ and that the curtilage concept is “a familiar one easily understood from our daily experience.” ⁵¹

Despite the Court’s aspiration for clear demarcations, however, in many cases the line between the private home and public space has turned out to be “blurred and fluid.” ⁵² The Seventh Circuit observed, for example, that: “The lines are not so clear, however, because exactly where outside ends and where the home begins is not a point immediately obvious.” ⁵³ To complicate matters further, in Payton and Santana the Supreme Court has provided inconsistent guidance regarding the pragmatic applications of its door-centered jurisprudence.

Payton is a consolidation of two cases, both dealing with a New York statute that allows a warrantless entry into a home to make a felony arrest. ⁵⁴ In this decision, the Supreme Court struck down this New York statute, stating: “In terms that apply equally to seizures of property and to seizures of persons, the Fourth Amendment has drawn a firm line at the entrance to the house. Absent exigent circumstances, that threshold may not reasonably be crossed without a warrant.” ⁵⁵

Four years before its protective Payton decision, the Supreme Court issued United States v. Santana. ⁵⁶ In that case, the officers drove to Santana’s residence armed with probable cause, but lacking a warrant. Upon arrival, they saw Santana “standing in the doorway of the house.” ⁵⁷ One of the officers testified that “one step forward would have put her outside, one step backward would have put her in the vestibule of her residence.” ⁵⁸ The officers got out, shouted “police,” displayed their identification and approached Santana, who retreated into the house. The officers pursued, catching her in the vestibule. The Court upheld the arrest and subsequent search. ⁵⁹ Justice Rehnquist, writing for the majority, explained that:

While it may be true that under the common law of property the threshold of one’s dwelling is “private,” as is the yard surrounding the house, it is nonetheless clear that under the cases interpreting the Fourth Amendment Santana was in a “public” place. She was not in an area where she had any expectation of privacy. “What a person knowingly exposes to the public, even in his own house or office, is not a subject of Fourth Amendment protection.” ⁶⁰

Although it observed that when standing at her door Santana was within the private property of her home, the Court nonetheless decided that she did not have an expectation of privacy because she willingly exposed herself to public view. This lack of expectation then attached to Santana as she fled into the confines of her home. ⁶¹ The Court relied on Katz v. United States ⁶² and cited Hester v. United States ⁶³ for the proposition that because Santana “was not merely visible to the public, but was as exposed to public view, speech, hearing, and touch as if she had been standing completely outside her house,” she was able to be pursued into the house to be arrested and searched. ⁶⁴ The importance of vision (in this quote with a nod toward other sensorial properties) as the prime means for determining privacy rights cannot be overstated, raising the question: what will happen when physical matters such as doors no longer impede state vision? Until this happens, however, the door, with its substantive thingness and its symbolic powers, is the center of a ritualistic legal dance: one step forward, two steps back – with the suspect’s fate, toward either freedom or incarceration, hanging in the balance.

Applying Santana, the Fifth, ⁶⁵ Eighth, ⁶⁶ Ninth, ⁶⁷ and Tenth ⁶⁸ Circuits have all held that Fourth Amendment protections should not be afforded to that which the individual exposes to the public through an open door. The protective power of the door has thus largely been limited to its closed position. Nonetheless, this limitation has been complicated both by the circumstances that precede the act of crossing the threshold and by the intentions of the actors on the two sides of the door. For example, while the courts have clarified that when a person stands at the door through her own agency she loses her protections, they have complicated the inquiry when a searched person is forced to the door or led to the door by ruse. The next section will discuss some of the complicating factors of the Open Door’s bright line approach.

IV. Door Configurations: A Jurisprudence of Vision

Circuit courts have varied in their application of the Supreme Court’s threshold and curtilage rules, with the result being far removed from the Supreme Court’s aspiration for a bright-line rule. In United States v. Gori, ⁶⁹ for example, the police accompanied a delivery woman as she knocked on an apartment door, and when one of the occupants opened the door wide, the police displayed their badge and ordered everyone present, including the defendant, out of the apartment at gunpoint. ⁷⁰ The Second Circuit ruled that this was not a violation of Payton because “what a person chooses voluntarily to expose to public view thereby loses its Fourth Amendment protection.” The critical facts for the majority were that the door was voluntarily opened to an invitee. At that moment, they stated, what was inside was exposed to public view. “[W]here blinds are raised, police are entitled to peer through back window of home,” the court explained. ⁷¹

Sonia Sotomayor (while serving on this court) dissented, arguing that per the majority opinion, the opening of the door transforms the entire home into a public place. In her words: “an open door translates into an ‘open season’ on the individual inside.” ⁷² Sotomayor vigorously objected to this result, ⁷³ noting that “if police cannot seize objects in plain view without probable cause when they are already legitimately standing inside an individual’s home, it is unclear why the Fourth Amendment would permit them both to enter the home from outside and to seize the object or person without probable cause, as the majority holds in this case.” ⁷⁴ Seventh Circuit Judge Richard Posner ⁷⁵ also criticized Gori, claiming that since few people would refuse to open the door to the police, “the effect of the rule of [Gori] is to undermine, for no good reason that we can see, the principle that a warrant is required for entry into the home [excluding specific exceptions].” ⁷⁶ Posner opposed Gori for tacitly taking advantage of typical door behavior – namely, that most people will automatically respond to a knock by opening their door.

The Tenth Circuit approached matters differently than the majority in Gori. In United States v. Flowers, ⁷⁷ the defendant was selling liquor illegally from his home through a small panel, revealing only his hand, a portion of his arm, and his voice in the process. ⁷⁸ After the police conducted business with Flowers, they approached the front door. Flowers voluntarily opened it, and the police entered the home and arrested him there. The District Court said that Flowers “knowingly exposed too much of himself to the public” ⁷⁹ to claim his Fourth Amendment rights were violated and that Flowers had no legitimate expectation of privacy because he was in a “sufficiently public” place. ⁸⁰ The Tenth Circuit Court of Appeals reversed, finding that Flowers demonstrated “a conscious intention” to protect his rights by using the hole in the wall and therefore affirming his rights. ⁸¹ In the words of the court:

In contrast [to Santana and McKinnon], here the suspect was not visible to the public and his doorway was not open to public view. Rather only Flowers’ hand and arm were visible and he used a hole in the wall so that he would not have to open his door and neither he nor the interior of his house would be open to public view. Unlike the situations in Santana and McKinnon, Flowers was not as exposed to public view, speech, hearing, and touch as if he had been standing completely outside his house. ⁸²

In determining the legal relationship between the larger hole in the wall (the door) and the smaller hole in the wall (the panel), the court’s decision again illuminates the importance of vision to legal practices and pronunciations. ⁸³ Whereas the small hole afforded no views of the home’s interior and in fact exposed only Flowers’ hand and arm, an open door (and, similarly, a window) would have enabled such an interior view of the home, thereby triggering the argument that Flowers voluntarily exposed his home to public view. “A room with a view” – from the outside in, that is – thus frustrates reasonable expectations of privacy. The door in these instances becomes important not only in its function as enabling the movement of human bodies in and out, but also in its function as a large window that enables the public’s gaze into one’s abode. And in this case: because the front door to his home was closed during the liquor exchange, Flowers’ rights were deemed worth protecting. ⁸⁴ The material relationship between a hole in the wall that is designed for full bodily entry (and that also enables significant viewing) and a lesser hole in the wall that performs functions other than entry and vision is thus an essential component of the particular legal relationship in this case.

The legal distinction between open and closed doors, and its subsequent triggering of full or zero constitutional protections, is further complicated in cases with more than one door, especially when these doors are in different states of openness. When a second door is opaque and closed, for example, the location of the bright line at the front of the home changes, depending on whether the first door is open or closed, again emphasizing the role of vision in assigning constitutional protections. In United States v. Arellano-Ochoa, ⁸⁵ for example, the Ninth Circuit condemned the police’s opening of a screen door without a warrant or other justifications, but stated that opening a screen door backed by a closed solid door does not violate reasonable expectations of privacy. ⁸⁶ In United States v. Sheridan Walker, ⁸⁷ the Tenth Circuit held that after knocking on a screen door, the defendant’s expectation of privacy was not violated when the police opened the screen door to knock on the interior door. ⁸⁸ The court based this reasoning on the conclusion that most visitors would do the same. ⁸⁹

Finally, the motives and actions of humans on both sides of the door have also factored into the juridical analysis. The Seventh Circuit clarified, for example, that:

there is a significant difference between a person who for no reason voluntarily decides to stand in his open doorway, and a person who merely answers a knock on his door. The person who answers the knock and stays within the house is not voluntarily exposing himself ‘to public view… as if [he is] standing completely outside [his] house.’ ⁹⁰

The Eighth Circuit drew a similar distinction, ⁹¹ describing the doorway as a public place when a suspect is voluntarily standing there, but not when the suspect is compelled – for instance, through the police knocking at the door. ⁹² Courts have similarly invalidated arrests where the police have attempted to circumvent Payton by summoning a suspect to the doorway so that the arrest could occur in a public place. ⁹³ Clearly, the bright line rule shifts depending on who stands where, when, and why in relation to the door. Some courts have held that the legal protections disappear once one opens the door, ⁹⁴ other courts found otherwise, ⁹⁵ and some have voiced emotional objections in dissent. ⁹⁶ Fourth Amendment rights and protections therefore hinge upon the myriad material properties of the door. Open doors, ⁹⁷ partially open doors, ⁹⁸ and being on the wrong side of the door ⁹⁹ – have all factored into the judicial calculations of a person’s rights vis-à-vis the police.

The juridical test, however, has not been strictly material and geographical. In fact, some courts have pointed out that an application of an exclusively geographical test would lead to undesirable results. Whereas Justice Powell declared that “physical entry into the home is the chief evil against which the fourth amendment is directed,” ¹⁰⁰ he also asserted that a physical entry is not necessary because the Amendment’s “broader spirit now shields private speech from unreasonable surveillance.” He further explains that: “Our decision in Katz refused to lock the Fourth Amendment into instances of actual physical trespass.’’ Rather, the Amendment governs “not only the seizure of tangible items, but extends as well to the recording of oral statements . . . without any ‘technical trespass under . . . local property law.’” ¹⁰¹ Delivering the opinion of the Court, Justice Powell relied on the important Katz decision in holding that electronic surveillance necessitates the application of Fourth Amendment safeguards. Various courts have also extended the physical test when there was “constructive entry” by the police, ¹⁰² including entry by voice, ¹⁰³ telephone call, ¹⁰⁴ or show of force. ¹⁰⁵ These decisions explain that denying legal protections in such cases would problematically enable the police to comply with Payton so long as they do not cross the line of the threshold – namely, walk through the door. ¹⁰⁶

Alongside the door jurisprudence that has developed around bodily entry, courts have also struggled to define the protections afforded to the images observed though the door. Transparent doors are particularly interesting in this context. On the one hand, such doors separate inside from outside in terms of bodily entry, thereby functioning like closed doors; on the other hand, they function like open doors in that they enable parties to see both in and out. While transparent and open doors allow the police to see into the dwelling, they also enable those within the dwelling to observe the police outside the door. For this reason, the government has allowed such situations as grounds for exigency claims, namely that the occupant may be more likely to destroy or get rid of evidence ¹⁰⁷ or as a basis for arguments mooting the knock and announce requirement. ¹⁰⁸ Such circumstances could additionally serve as proof of consent, as offered in dicta by Justice Black in his dissent in Bumper. ¹⁰⁹ There, the relevant issue was whether the suspect’s consent was valid when the police stated that they had a warrant although they did not. ¹¹⁰ Black noted that the conversation between the police officer and the defendant’s grandmother, who consented for the police search of the home, took place through a screen door. ¹¹¹ He bolstered the argument for consent by pointing out that the defendant’s grandmother was able to see the officer through the door, that he did not appear to have a warrant with him, and that she nonetheless allowed him in.

Acts of locking or unlocking one’s door have also factored into Fourth Amendment decisions. In certain instances, the police arrested suspects for obstruction when they locked a door to prevent police entry, though generally not when they failed to unlock a door. ¹¹² The courts have, additionally, interpreted various door-slamming actions. In Wong Sun ¹¹³ and in Miller v. United States ¹¹⁴ the Court interpreted the suspect’s slamming and subsequent flight from the door down the hallway as signifying “a guilty knowledge no more clearly than it did a natural desire to repel an apparently unauthorized intrusion.” ¹¹⁵ The dissent finds this interpretation “incredible in the light of the record,” stating that “the officer’s showing of his badge and announcement that he was a narcotics agent immediately put [the suspect] in flight behind the slamming door. To conclude otherwise takes all prizes as a non sequitur.” ¹¹⁶ Finally, in Parra v. City of Chino, ¹¹⁷ the police spoke to Vivian Parra through the screen door, asking to see her husband, Manuel. ¹¹⁸ She told the police that Manuel would be right out, and then closed and apparently locked the screen door before proceeding to fetch him. The police inferred from her locking the door and from previous experience with this suspect that Manuel presented a flight risk, and barged in. ¹¹⁹ The court decided that because the officers knew that the suspect had previously fled from police, they had reason to believe that the suspect would resist arrest again. Based on these facts, the court determined that the officers satisfied the knock and announce requirement (as detailed below). ¹²⁰

While the Fourth Amendment has been the primary domain for door-related jurisprudence, the courts have addressed threshold problems through other legal arenas as well. ¹²¹ For example, in Sabbath v. United States, ¹²² the Supreme Court described in a footnote ¹²³ the useful analogy of burglary to the US Code’s knock and announce rule, ¹²⁴ quoting from commentators that: “What constitutes ‘breaking’ seems to be the same as in burglary: lifting a latch, turning a door knob, unhooking a chain or hasp, removing a prop to, or pushing open, a closed door of entrance to the house, – even a closed screen door . . . is a breaking.” ¹²⁵ Here and there, such nuanced features and states of the burglarized door were deemed relevant in determining Fourth Amendment issues. Features that have factored in the analysis include whether a door is locked, latched, ¹²⁶ on a spring, ¹²⁷ wide-open, ¹²⁸ and whether a screen door exists ¹²⁹ – indeed, almost all possible features of the burglarized door have been considered. ¹³⁰ Whereas the state practices discretion in its decision whether to record a crime as a burglary or not based on these factors, ¹³¹ the courts are unlikely to hold police officers and burglars to the same standards.

V. The Door’s Spatio-Temporality: Knock, Knock, Knocking on Suspect’s Door

Until now, I have mostly focused on the police’s physical crossing of the door’s threshold without warrant or exigency. Even when equipped with a warrant, however, the police are typically required to perform what is called a knock and announce procedure before entering the home. Such a procedure requires that the police knock on the door, identify themselves as police, and explain their purpose for seeking entry. ¹³² Only after their entry has been refused, or after a specified length of time has passed, may the police use force to enter. ¹³³ The Supreme Court has ruled that the amount of wait required in any given case depends on the nature of the evidence, the size of the dwelling, the time of day, and other factors. Hence, in United States v. Banks (2003), the Court approved a forceful entry by officers after they had knocked, announced, and waited for 15 to 20 seconds, ¹³⁴ taking into account the risk of drug evidence disposal in evaluating the reasonableness of the waiting time. ¹³⁵ Still, the Court reasoned that most people keep their doors locked, and hence “entering without knocking will normally do some damage.” ¹³⁶

A few years later, in Hudson v. Michigan (2006) the police arrived to execute a warrant, announced their presence, but waited for only three to five seconds before turning the knob of the unlocked front door and entering Hudson’s home. Hudson moved to suppress the inculpatory evidence they found there, arguing that the premature entry violated his Fourth Amendment rights. ¹³⁷ “How many seconds’ wait are too few?” asked Justice Scalia, concluding that: “Happily, these issues do not confront us here.” Indeed, although there was no disagreement that the knock and announce rule was violated in this case, the majority held that the exclusionary rule does not apply.

Justice Scalia wrote the majority opinion. He first noted that: “Until a valid warrant has issued, citizens are entitled to shield their persons, houses, papers, and effects, from the government’s scrutiny. Exclusion of the evidence obtained by a warrantless search vindicates that entitlement.” However,

The interests protected by the knock-and-announce requirement are quite different – and do not include the shielding of potential evidence from the government’s eyes. One of those interests is the protection of human life and limb, because an unannounced entry may provoke violence in supposed self-defense by the surprised resident. Another interest is the protection of property. Breaking a house (as the old cases typically put it) absent an announcement would penalize someone who “did not know of the process, of which, if he had notice, it is to be presumed that he would obey it . . .” And thirdly, the knock-and-announce rule protects those elements of privacy and dignity that can be destroyed by a sudden entrance . . . The brief interlude between announcement and entry with a warrant may be the opportunity that an individual has to pull on clothes or get out of bed. ¹³⁸

Scalia clarifies, finally, that “What the knock-and-announce rule has never protected, however, is one’s interest in preventing the government from seeing or taking evidence described in a warrant. Since the interests that were violated in this case have nothing to do with the seizure of the evidence, the exclusionary rule is inapplicable.” ¹³⁹

Despite the waning of the knock and announce rule, the police are still required to perform the physical, temporal, and legal ritual of knocking, waiting, and announcing their presence at the door of a home–all part of the reasonableness requirement. Such a multi-sensory procedure that involves rapping, pausing, and using voice reinforces the significance of the door as a technology that separates the outside from the inside, effectively construing distinct spatiolegal categories. How will the knock and announce rule change when doors are no longer made of wood that can produce the sound of a knock, or when human police officers are replaced by dogs or machines? I will return to these questions in the conclusion.

VI. Mobile Doors

In South Dakota v. Opperman (1976), ¹⁴⁰ the Supreme Court elaborated on the privacy rights users have in cars. There, the Court held that the car operator has the power to exclude others by locking the doors and rolling up the windows (akin to home dwellers). ¹⁴¹ One year later, this heightened protection was functionally eviscerated in Pennsylvania v. Mimms (1977), where the Court determined that the police may order a suspect out of her car or demand that she open her door. ¹⁴² Once the door is open, the courts have generally held that the police may look inside. ¹⁴³ The police have often taken advantage of this opportunity for obtaining evidence to search or arrest suspects. ¹⁴⁴ Moreover, unlike the home, the car is not encircled by a protective curtilage zone and, hence, the police may stand just outside the car and peer into its interior through the windows, negating any minimal protections that the door may have afforded to this relatively small space. ¹⁴⁵

Three Supreme Court cases discussed police invasion into the protected space of the car through its door – and in all three cases the Court found that they acted properly. In the first case, New York v. Class, ¹⁴⁶ the defendant was stopped for speeding. The officer opened the car door to find the VIN number, which he believed was located in the doorjamb of this particular model of car. ¹⁴⁷ When he did not find it, the officer proceeded to look in the next most likely spot, which was obscured by a few papers. ¹⁴⁸ When moving the papers, the officer found a gun. ¹⁴⁹ The Court decided that the defendant’s rights were not violated both because there was no privacy interest in the VIN number and because the search was “sufficiently unintrusive.” ¹⁵⁰ In the words of the Court: “He did not even intrude into the interior at all until after he had checked the doorjamb for the VIN. When he did intrude, the officer simply reached directly for the unprotected space where the VIN was located to move the offending papers.” ¹⁵¹

The second Supreme Court case, Adams v. Williams ¹⁵² raised a similar dilemma. There, the officer requested that the defendant open his car door based on a reliable informant’s tip that the defendant had narcotics and a gun tucked in his waistband. ¹⁵³ Instead of opening the door, the defendant rolled down the window, and the officer reached in and grabbed the otherwise non-visible handgun. ¹⁵⁴ The Court applied Terry, ¹⁵⁵ finding the officer’s behavior reasonable. ¹⁵⁶ In this case, the defendant’s not opening the vehicle door was part of the officer’s justification to conduct the search. The Court stated:

Sgt. Connolly had ample reason to fear for his safety. When Williams rolled down his window, rather than complying with the policeman’s request to step out of the car so that his movements could more easily be seen, the revolver allegedly at Williams’ waist became an even greater threat. Under these circumstances the policeman’s action in reaching to the spot where the gun was thought to be hidden constituted a limited intrusion designed to insure his safety, and we conclude that it was reasonable. The loaded gun seized as a result of this intrusion was therefore admissible at Williams’ trial. ¹⁵⁷

Finally, in Massachusetts v. Podgurski the Supreme Court dealt with a slightly different type of threshold problem. ¹⁵⁸ In that case, the officer stuck his head through a van door that was partially open, and observed contraband. ¹⁵⁹ Rehnquist felt that this intrusion was minimal because it was the functional equivalent of standing just outside of the threshold. ¹⁶⁰

The end result of these three cases appears to be that the car door is not a very effective spatiolegal technology for excluding the police. ¹⁶¹ Quite the contrary, the very existence of the door – and the perceived risk and danger of what lies beyond it – has at times provided the police with the required justification for carrying out searches and seizures. In Ornelas v. United States, for example, an officer observed a loose panel in the door, using this observation, among others, to constitute probable cause for a search. ¹⁶²

VII. Conclusion: The Door as a Matter of Freedom

I blew out the light, I tip-toed the floor, And raised both hands,In prayer to the door.

—Robert Frost, “The Lockless Door” ¹⁶³

To prevent incursions to the home “by even a fraction of an inch,” ¹⁶⁴ U.S. courts have attempted a concrete and concise delineation of the home’s threshold. Simultaneously, the courts have declared that “we need not pull out our rulers” ¹⁶⁵ for “splitting fractions of an inch can be a very treacherous endeavor, producing arbitrary results.” ¹⁶⁶ The details of where exactly one stands in relation to the door may be better left “descriptive,” ¹⁶⁷ the courts have said, since such “metaphysical subtleties” ¹⁶⁸ are ineffective and dangerous ways to discuss Fourth Amendment concerns. ¹⁶⁹ In the words of Judge Borden: “By opening the door . . . and standing there briefly so that our feet are on the threshold rather than just inside it, we do not abandon our heightened expectation of privacy in our homes and place ourselves in a public place.” ¹⁷⁰

The door is not only a technological miracle, as Latour has observed, but also a legal one. Once the threshold is crossed, a transformation occurs. Tracing the material and symbolic importance of the door for establishing Fourth Amendment protections, this article has attempted to illuminate the importance of matter – both physical and symbolic – in juridical discourse. In particular, I have highlighted how various door conditions affect the level of protection granted to those situated inside the door and the importance of vision for establishing legally accepted expectations of privacy. Finally, I have shown that the courts have interpreted doors differently in the context of cars. A comparison of car to house doors has highlighted that beyond their shared liminality across spaces, the sacredness of the home in American jurisprudence is what grants certain doors but not others heightened legal protections.

I have also pointed out that we may be witnessing the twilight of the physical door era – at least as we currently know it – and the beginning of a new, virtual door era in Fourth Amendment jurisprudence. Indeed, advanced technologies – such as highly trained police dogs, Global Positioning Systems, and infrared thermal devices – are already alerting to, and thereby bringing to view, both things and information that previously resided behind firmly closed doors. As is becoming apparent from a growing number of Fourth Amendment cases – including Karo, ¹⁷¹ Kyllo, ¹⁷² Jones, ¹⁷³ and Jardines ¹⁷⁴ – the Supreme Court has been attempting to preserve the familiar physical invasion test of the physical door era. At the same time, the Court has also been responding to the contemporary realities of “seeing through walls” and “cyber doors,” which increasingly call into question the continued legal primacy of physical doors. As the alterations of physical and technological matter present increasingly sophisticated challenges to the distinctions between inside and outside, private and public, and prohibited and accepted visions, the Supreme Court will need to carefully articulate what it deems is worth protecting on the other side of the door.