Knock and Talks: Faithfully Applying Social Norms to Prevent Unconstitutional Police Intrusion upon the Home

Under the Fourth Amendment, the home is protected as “first among equals.”11

Even before the founding, the common law declared property rights to be “sacred.”22 Despite these words of high reverence, a well-established doctrine of American law permits a police officer to approach any house in the country, at nearly any time, for any reason, and stand squarely on the doorstep to knock. But when no one comes to the door, what the officer can and cannot do is anything but well-established.

The Fourth Amendment protects not just the interior of a house, but also its curtilage, defined as an area that harbors the “intimate activity associated with the ‘sanctity of a man’s home and the privacies of life.’”33

Thus, police must secure a warrant supported by probable cause in order to search areas outside of a suspect’s home.44 To determine whether an area of the home is within the curtilage, courts look at four factors laid out in United States v. Dunn:55 “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.”66 One area clearly afforded this protection is the front porch of a house, the “classic exemplar” of an area within the curtilage.77

Even though the home is a constitutionally protected area, the police have enjoyed a long-recognized ability to warrantlessly enter the curtilage of the home to conduct a “knock and talk,” where an officer will knock on the front door and request to speak with an occupant.88

Should the occupant consent to a search, any evidence found by the police will be admissible in court.99 Additionally, while conducting a knock and talk, police may see evidence that will then be admissible under the plain view doctrine.1010 The knock and talk can therefore be a powerful police tool for entering and investigating constitutionally protected areas, even when police lack the probable cause necessary to obtain a warrant.

Although state and federal courts had already recognized the knock and talk exception for decades, the Supreme Court did not weigh in on knock and talks until the relatively recent cases of Kentucky v. King1111

and Florida v. Jardines.1212 In those cases, the Court affirmed the justification that lower courts had often made for the exception: there is an implied social license that allows any visitor to approach the home, knock, and be received.1313 But while the Court has recognized the legality of knock and talks, its decisions provide little guidance on the scope of the exception, leaving ambiguities as to which parts of the home may be visited and for how long. Indeed, in the past, the Court explicitly declined to state whether the knock and talk exception allows police to approach any entrance that is open to visitors or only applies to the front door.1414 The Court also says little on whether factors like the time of day, fences, the layout of the property, and signage could ever revoke the implicit license to approach the home. If the license can be revoked, some circumstances could prevent the police from even approaching the home to conduct a knock and talk.

The clarity of knock and talk guidelines is also important for the appropriate enforcement of Fourth Amendment rights. Often, the only remedy for a homeowner whose rights have been violated during a knock and talk is a 42 U.S.C. § 1983 claim (“Section 1983”).1515

Section 1983 enables individuals to sue state officials for depriving them of their rights.1616 However, police officers can claim qualified immunity if the right in question was not clearly established,1717 and courts are divided on what rights, if any, Jardines and other cases recognize.1818 As such, a coherent understanding of Jardines’s impact on the Fourth Amendment landscape is crucial to determining whether police officers can be held civilly liable for their behavior during a knock and talk.

This Comment focuses on judicial attempts to define the physical and temporal scope of the knock and talk exception in relation to Jardines and argues that most circuits have adopted rules that cannot be justified under Fourth Amendment jurisprudence. Accordingly, this Comment proposes guidelines that would bring knock and talk practices in line with the social license that permits them. Part II provides a background of the general types of police behavior that have long been considered allowed by the knock and talk exception, as well as an overview of the Court’s landmark decision in Jardines. Part III examines the heavily fractured state of current knock and talk jurisprudence, with a particular focus on how courts have interpreted Jardinesand its discussion of the implied license to approach the home. Part III also identifies which circuits heavily constrain where police may go during a knock and talk, and which circuits allow police to intrude on the curtilage even after no one has answered the door. Part IV argues that under Jardines, the Fourth Amendment compels a set of limitations on the scope of knock and talks. Specifically, these limitations would require police to only conduct knock and talks at entrances to the home and forbid police from extending the duration of knock and talks without explicit invitation from an occupant. Part V concludes.

There has been a longstanding recognition of an implied license for people to approach a house and knock on the door.1919

Before the Supreme Court’s decisions in Jardines and King, courts across America had already developed a largely similar body of case law concerning knock and talks.2020 Generally, courts have held that the knock and talk exception permits police to approach any entrance or area that would be accessible to visitors.2121 Courts have also generally permitted police to stay at the door and continue to knock if no one answers the first knock, particularly when the police believe someone is inside the residence.2222 When no one answers an officer’s knocking, police have been able to knock elsewhere on the property, including side doors, back doors, garage doors, and even areas not attached to the home like cars and sheds.2323 And though courts have spoken disapprovingly of knock and talks performed late at night, they have often allowed them anyway.2424

Courts have generally avoided saying what is necessary for a resident to revoke the implied license to approach the door. In many pre-Jardines cases, courts highlighted the lack of a “no trespassing” sign as additional confirmation that there was an implied license to conduct a knock and talk. However, even in cases where such a sign was posted on the property, courts have still found an implied license.

The first time that the Supreme Court considered the social license involved in a knock and talk was in Kentucky v. King.2525

In that case, police knocked on the door of an apartment that smelled of marijuana to announce their presence.2626 After they heard sounds of evidence being destroyed, the police kicked in the door and found narcotics.2727 Although the knock itself was not the case’s main issue, the Court said that the officers were allowed to knock on the door without a warrant because that was “no more than any private citizen might do” and that “the occupant has no obligation to open the door or to speak.”2828 The Court emphasized that its holding strongly protected the privacy rights at interest in the Fourth Amendment because an occupant’s refusal to answer the door would drive a warrantless investigation to “a conspicuously low point.”2929

The Supreme Court extensively discussed knock and talks for the first time in Florida v. Jardines.3030

In that case, police brought a drug-sniffing dog to the defendant’s home to investigate a suspected marijuana growing operation.3131 The dog went onto the front porch and alerted for drugs.3232 Using this information, the police secured a warrant.3333 The Court held that using a police dog to sniff for drugs within the curtilage of the home is a search under the Fourth Amendment, which therefore requires a warrant.3434 Justice Scalia distinguished this behavior from a knock and talk, saying that while a knock and talk was permitted under an implied social license, taking a police dog within the curtilage to search for drugs was not covered by any implied license and required a warrant.3535 The implicit license “typically permits the visitor to approach the home by the front path, knock promptly, wait briefly to be received, and then (absent invitation to linger longer) leave.”3636 The license is also limited in scope to a specific purpose: “the background social norms that invite a visitor to the front door do not invite him there to conduct a search.”3737 Since the dog was there to explore the home and sniff for evidence, this exceeded the scope of the social license.

It is important to note that Justice Scalia’s opinion relies upon “the traditional property-based understanding of the Fourth Amendment.”3838

Early Fourth Amendment jurisprudence understood the Amendment as protecting property interests.3939 The English common law case Entick v. Carrington,4040 described by the Supreme Court as “‘undoubtedly familiar’ to ‘every American Statesman’ at the time of the founding,”4141 stated that “[o]ur law holds the property of every man so sacred, that no man can set his foot upon his neighbour’s close without his leave.”4242 Applying this axiom to Fourth Amendment issues, early American courts considered whether the government had intruded on the defendant’s property.

This understanding contrasts with the now common privacy-based understanding of the Fourth Amendment stated in Katz v. United States.4343

Under Katz, courts consider whether police have invaded an area where there is a “reasonable expectation of privacy.”4444 Katz famously rebuffed a purely property-based interpretation of the Fourth Amendment, with the Court saying “[t]he Fourth Amendment protects people, not places.”4545 But the Court in Jardines said it did not need to determine whether there was a reasonable expectation of privacy from a police dog sniffing on the front porch.4646 A Katz analysis was unnecessary because the police had already violated the Fourth Amendment by physically intruding on Jardines’s property to obtain information.4747 A solely property-based analysis was acceptable because “[t]he Katz reasonable-expectations test ‘has been added to, not substituted for,’ the traditional property-based understanding of the Fourth Amendment.”4848

Although Jardines discussed knock and talks at some length, it was not immediately clear whether the landscape of knock and talks had changed at all. The challenged behavior in the case was the use of a police dog to gather information. The officers in Jardines never even attempted a knock and talk. Many courts nevertheless read Jardines as redefining the scope of the knock and talk exception. The First Circuit, for example, reads Jardines as generally defining the scope of the implied social license to approach and knock on the house door, rather than applying to the specific context of a search for evidence using a police dog.4949

In French v. Merrill, the First Circuit concluded “it was not the dog that was the problem in [Jardines].”5050 Instead, the problem was that the officers had entered a protected area to gather information without having any license to be there.5151 And when the First Circuit denied a rehearing en banc, the majority reiterated that “Jardines was all about the nature and scope of the implied license to enter the curtilage of a private residence without a warrant.”5252

Judge Lynch of the First Circuit dissented from the majority’s interpretation of Jardines, saying that Jardines is inapplicable in the context of a knock and talk “where there was no police dog or any other instrumentality used.”5353

In Judge Lynch’s view, “Jardines is not about the limitations, if any, on the duration or location of a knock and talk license to contact the resident of a home, and thus could not clearly establish the purported illegality of the officers’ conduct [in French].”5454 The Tenth Circuit agreed. In United States v. Carloss,5555 the court determined that Jardines did not change prior circuit precedent, nor did it restrict knock and talks, because a knock and talk did not occur in Jardines.5656

The Fifth Circuit has also analyzed a knock and talk outside of the context of Jardines. In Westfall v. Luna,5757

another Section 1983 claim, the police attempted two additional knock and talks after the person answering the door had closed it.5858 The Fifth Circuit ultimately declined to say whether the officers’ behavior was a valid knock and talk but notably did not use Jardines in its analysis.5959 Instead, the court continued to cite pre-Jardines Fifth Circuit precedent concerning the scope of the knock and talk exception.6060 The Fifth Circuit’s decision to avoid Jardines is curious given that the appellant’s first argument on appeal was that the police had violated the Fourth Amendment under Jardines.6161

The Eleventh Circuit takes a similar position to the First Circuit, arguing that Jardines is not limited to the specific facts of the case. Rather, “[Jardines] extends to any police intrusion onto curtilage that exceeds the customary license extended to all, whether measured by officers’ actions or their intent.”6262

While the Supreme Court has not directly said how broadly Jardines must be read, multiple Justices recently asserted in a statement concerning the denial of certiorari that Jardines protects the curtilage from far more than police dogs. In Bovat v. Vermont,6363

the Court considered a Vermont Supreme Court ruling that police officers did not violate the Fourth Amendment by walking up a private driveway and peering into a suspect’s garage for roughly fifteen minutes.6464 Relying on its pre-Jardines precedent, the Vermont Supreme Court held that while the garage and driveway were within the curtilage, driveways are “semiprivate areas” that are not covered by the Fourth Amendment.6565 Justice Gorsuch, joined by Justices Sotomayor and Kagan, questioned why the Vermont Supreme Court had decided the case “without reference to Jardines,” because “that case’s teachings almost certainly required a different result.”6666 To Justice Gorsuch, “Jardinesplainly held that the home’s curtilage and observations made anywhere within its bounds are covered by the Fourth Amendment; no exceptions. And the Fourth Amendment hardly tolerates the sort of meandering search that took place here.”6767 While the case at issue did not involve a knock and talk, Justice Gorsuch’s statements demonstrate that at least three Justices likely view Jardines as protecting the entire curtilage from unauthorized intrusion. Taking heed of Justice Gorsuch’s admonishment, the Vermont Supreme Court overturned State v. Bovat6868 two years later.6969 This time, the court applied Jardines to conclude that an officer could not conduct a search in the driveway of a home after no one answered his knocks at the front door.7070

The Third Circuit attempted to address the new role of Jardines in Carman v. Carroll,7171

a Section 1983 action against police officers who warrantlessly entered Carman’s property and went directly to the back door.7272 The Third Circuit used the language of Jardines alongside its own precedent to hold that a knock and talk must begin at the front door.7373 The Third Circuit also determined that the officers were not entitled to qualified immunity because the constitutional rights at issue were clearly established at the time of the encounter.7474 The Third Circuit could not rely on Jardines for its qualified immunity holding since the events of the case occurred before Jardines was decided.7575 But the Third Circuit said its own precedents at the time clearly established that a knock and talk must begin at the front door. The Supreme Court disagreed, stating that the Third Circuit’s cited decision was insufficient.7676 The Court’s Per Curiam decision did not even mention Jardines and explicitly declined to state whether a knock and talk must begin at the front door.7777

The First Circuit also likely views Jardines as restricting police to approaches at the front door. In French v. Merrill,7878

police attempted a knock and talk but received no response.7979 As the officers were leaving, one of them noticed a figure at a window who, upon being spotted, quickly covered the window and turned out the lights.8080 The police then went back to the front door and knocked again, and after receiving no response, proceeded to the side of the house and knocked on the occupant’s bedroom window frame.8181 The First Circuit found that the police officers did not have qualified immunity from a Section 1983 claim because their behaviors clearly violated the law established in Jardines.8282

In United States v. Wells,8383

the Eighth Circuit considered a case where police proceeded directly into the backyard of a house to investigate reports of a methamphetamine lab being run from a rear building.8484 Once in the backyard, police conducted a knock and talk at the back door and subsequently discovered drugs.8585 The Eighth Circuit determined that this knock and talk violated the Fourth Amendment, saying “[w]e are not prepared to extend the [knock and talk] rule to situations in which the police forgo the knock at the front door and, without any reason to believe the homeowner will be found there, proceed directly to the backyard.”8686

The Fourth and Eleventh Circuits have held that the police may conduct knock and talks beyond the front door of the house and that the knock and talk exception even extends to circumstances where the police do not knock on a door.8787

In United States v. Walker,8888

police officers knocked on the front door of a house, received no response, and left.8989 Later that night, instead of approaching the front door again, the officers went to a carport adjacent to the house and knocked on the car’s window.9090 The defendant, who was sleeping inside the car, answered the police and was arrested for evidence that the police subsequently found in plain view.9191 The Eleventh Circuit first held that the police had not objectively revealed a purpose to search under Jardines; rather, they had simply approached to speak with the homeowner.9292 Walker found this to be “squarely within the scope of the knock and talk exception.”9393 The court also held that knocking on the car window was permitted under the knock and talk exception because it was only a “small departure from the front door,”9494 which the Eleventh Circuit considered permissible.9595

In the Fourth Circuit’s view, “although the knock-and-talk doctrine is sometimes framed as a right to approach the home by the front path or knock on a front door . . . we have made clear that the implicit license is broader than that.”9696

In Covey v. Assessor of Ohio Cnty.,9797 officers received a tip that the defendant was growing marijuana behind his home. The officers then arrived at the property, entered the curtilage, and advanced to the back of the house, where the defendant was located.9898 Police then arrested the defendant and collected evidence.9999 The Fourth Circuit stated that if the police had entered the curtilage without having seen the defendant beforehand, they had violated the Fourth Amendment.100100 However, if the officers had seen the defendant from an area outside the curtilage, the knock and talk exception allowed the officers to approach him.101101 The court then remanded the case for further proceedings. The Covey court reiterated the Fourth Circuit’s pre-Jardines precedent that “[a]n officer may also bypass the front door (or another entry point usually used by visitors) when circumstances reasonably indicate that the officer might find the homeowner elsewhere on the property.”102102 Thus, an officer can head directly to the backyard of a property without knocking at the front door,103103 or approach residents standing in a driveway.104104

Before Jardines, the Sixth Circuit had held that officers could take reasonable steps to attempt to speak with an occupant when “circumstances indicate that someone is home” and the officer’s knocking produced no response.105105

But the Sixth Circuit later overturned this precedent after determining that Jardines forbids this practice.106106 Instead, officers cannot “linger on the curtilage once they have exhausted the ‘implied invitation extended to all guests,’ even if they suspect that someone is inside.”107107

The First Circuit similarly maintains that if an occupant does not come to the door, the police cannot persist in attempting additional knock and talks. In French v. Merrill,108108

officers attempted a knock and talk, but received no response and left the house. Despite the officers stating that they thought the occupant did not want to talk, they entered the curtilage later that night to knock on the door again.109109 The First Circuit said that this behavior exceeded the social license necessary for a knock and talk, since “the mere fact that [the defendant] did not answer the door cannot tip the balance in the officers’ favor.”110110

In multiple pre-Jardines case, the Fifth Circuit held that when nobody answers the door, officers must end a knock and talk and pursue different strategies.111111

But the Fifth Circuit did not limit officers to only knocking at a single door before needing to withdraw. After knocking on the front door and receiving no response, “[officers] might have then knocked on the back door or the door to the back house.”112112 Nonetheless, police were not allowed to use the knock and talk exception to peer through a bedroom window on the side of the house after receiving no response at the front door.113113 The Fifth Circuit also rejected a Jardines challenge to a knock and talk where police continued to knock for several minutes after seeing someone peer through the blinds but not answer the door.114114

In United States v. Carloss,115115

the Tenth Circuit examined a knock and talk that lasted for several minutes.116116 The court declined to set a time limit on how long officers could knock before exceeding the license of a knock and talk.117117 The court found that the officers did not linger on the curtilage for too long despite knocking for several minutes. The Court considered it relevant that the officers heard movement inside the house, which “encouraged” them to remain at the door, especially because no one inside the house demanded that the officers leave.118118

The Supreme Court’s jurisprudence requires the conclusion that warrantless police activity within the curtilage after a knock and talk fails violates the Fourth Amendment. The social license of a knock and talk is merely a license to approach the home and knock, not a general license to speak with the occupants of the home. Once a knock and talk goes unanswered, the implied license has run its course. A police officer’s mere desire to speak to an occupant should not be used to expand or extend the license beyond what existed the moment the officer approached the home. This means that if the initial knock and talk fails, the officer cannot continue knocking or try knocking in new locations.

When Justice Scalia described the license underlying the knock and talk, he noted that the license arises from “the knocker on the front door.”119119

And he formulated the license itself as “permit[ting] the visitor to approach the home by the front path.”120120 While the Third Circuit reads Justice Scalia’s description of the license literally, finding that knock and talks must occur at the front door,121121 a literal reading is unwise for several reasons. First, there is no reason to think that the license can only extend to the front door. While the front door of a home typically has a prominent knocker of some sort, many homes have multiple doors with knockers or doorbells, suggesting that the resident anticipates visitors approaching from more than one entrance to establish contact. This would create an implied license to approach any of those doors. In addition, every residence is different, and it may not be obvious which door is the “front” door. Attempting to limit knock and talks to solely the front door could prove impractical, as this would be a difficult factual determination to make in many cases. Admittedly, the Third Circuit’s rule provides strong protection for residents from police intrusion. But a more realistic view of the social license involved demands a flexible understanding of knock and talks.

Courts are rightfully concerned that police would use a flexible standard to bypass the front door and instead search for a door that offers greater access to otherwise private areas of the home.122122

A well-applied understanding of the implied license, however, provides firm protection to these areas. Police are strictly limited to certain entrances to the home. Police must approach a door that faces the street or has visible characteristics like a doorbell, knocker, or mail slot. These features indicate that visitors are expected to arrive at those doors, providing a clear license to approach. Doors without such visible indicators, such as those in a backyard, cannot be approached when there are alternative entrances. Above all, courts must apply common sense and require the police to use a door that is available to visitors. Such a test “does not require fine-grained legal knowledge; it is generally managed without incident by the Nation’s Girl Scouts and trick-or-treaters.”123123

An important question to resolve between the circuits is whether the police can extend a knock and talk when they believe that someone is present in the house. A faithful reading of Jardines, coupled with a general understanding of the implicit license at issue, requires the answer to be no. As Jardines reiterated, the source of the implied license for an officer to approach the door of a home and knock is the “knocker” on the door.124124

This implied consent remains present whether the occupant is home or not. It would be nonsensical to say that by virtue of being home, an occupant gives greater consent to having his or her door knocked on. Granted, it would be more reasonable to knock on the door of a house known to be occupied, but Jardines makes clear that reasonableness “depends upon whether the officers had an implied license to enter” the curtilage.125125

Under this analysis, the Sixth Circuit is correct in maintaining that the police cannot linger at the front door simply because someone is inside.126126

The Tenth Circuit, on the other hand, is mistaken in concluding that officers who hear noises inside of a house are “encouraged” to stay.127127 The only action by an individual that should extend the social license is an “invitation to linger longer.”128128 Noises on their own are not invitations. When no one answers the door after several minutes of knocking, it is the very opposite of an invitation to linger.

Those in favor of allowing police to extend the duration of a knock and talk might argue that an occupant who refuses to answer the door to police is often attempting to hide, and police should not be forced to ignore suspicious behavior. Even so, to allow police to continue knocking when they believe someone is inside undermines the Court’s holding in King. In that case, the Court held that when police knock on a door, “the occupant has no obligation to open the door or to speak.”129129

The Court also suggested that an occupant’s right to not answer discourages police from abusing their ability to knock on doors. If an occupant chooses not to speak, “the investigation will have reached a conspicuously low point” because the police will need to leave until they can return with a warrant.130130 But under the Tenth Circuit’s analysis, if an occupant refuses to answer the door, the investigation is given additional justification to proceed. The curtilage of one’s home should not be made more vulnerable to intrusion on account of someone utilizing their rights under the Fourth Amendment.

Instead, the implicit license should only last for a short time after the first knock. Once it becomes clear that no one will respond, the police lose the license to remain on the curtilage and must leave. The police cannot linger on the curtilage or knock for minutes on end. While the sound of movement inside the home might be relevant because it could signify someone coming to the door, which would extend the license, someone answering the door would likely come shortly after hearing the knock. Accordingly, there is little benefit to allowing officers to spend an abnormal amount of time at the door because they suspect someone may be coming. Additionally, if an officer is truly interested in waiting to see if someone answers the door, the officer can always leave the curtilage and wait to see if someone comes to the door and provides consent for the police to reenter.

While the knock and talk exception allows police to enter the curtilage of the home without a warrant, there is no reason for courts to apply this exception to any police activities except those made near a doorway. It is important to remember that the Court has emphasized that the knock and talk results from a license to approach the door and knock. There is not, however, any license to simply attempt to speak to someone on their property. The Eleventh Circuit applied this principle incorrectly in Walkerwhen it allowed the police to leave the front door and approach a sleeping defendant elsewhere on the curtilage.131131

The court described this as a “small departure from the front door.”132132 While the distance between the front door and a carport was only a couple of feet, the legality of approaching each area is vastly different. There is no well-recognized social license for private citizens to approach a parked car and knock. Similarly, the Fourth Circuit is mistaken in allowing police to bypass knocking on the front door if they see someone elsewhere on the property.133133 To the Fourth Circuit, the mere sight of a person on the property is enough to create an implied license to approach.134134 This behavior is divorced from the license underlying a knock and talk, which derives from social customs related to approaching doorways.135135 There is no license to step onto another’s property just to speak with them.

These circuits formulate the knock and talk in a way that wrongfully undermines the private property interests that the Court recognized in Jardines. The Fourth Amendment protects the curtilage in order to defend “the right of a man to retreat into his own home and there be free from unreasonable governmental intrusion.”136136

Under cases like Walker and Covey, however, a resident’s presence on the curtilage gives the police increased license to warrantlessly enter the curtilage and attempt to initiate a conversation. This reading of the knock and talk exception paradoxically provides less recognition to the property interests of an occupied home than it does to an unoccupied one.

Preventing police from approaching and speaking to someone who is standing in plain sight could be seen as placing a significant burden on society’s interest in effective policing. But such a rule would not excessively interfere with police activities because it would simply require the police to avoid intruding upon the curtilage. This limitation does not prevent police from attempting to speak to a person, so long as they do so while respecting the property interests protected by the Fourth Amendment. Police would be free to stand on the sidewalk, for example, and attempt to converse at a distance. This would do nothing to prevent police from having a full conversation with visible residents and asking for consent to conduct a search. Critically, it would prohibit police from using the knock and talk to initiate a conversation that would not be feasible from the sidewalk or front door.

When it comes to expansion of the knock and talk exception, courts are too permissive of police officers expanding the bounds of the exception. Courts extend the knock and talk exception by declaring police oversteps justified by the circumstances. This is understandable, since the Supreme Court has stated that “[t]he touchstone of the Fourth Amendment is reasonableness.”137137

With this understanding, “the Court has consistently eschewed bright-line rules, instead emphasizing the fact-specific nature of the reasonableness inquiry.”138138 It may therefore seem unusual to suggest several bright-line rules constraining knock and talks, but there are multiple reasons to treat knock and talks as a unique exception to the warrant requirement.

First, there is a “presumption of unreasonableness that attaches to all warrantless home entries.”139139

Accordingly, “[b]efore agents of the government may invade the sanctity of the home, the burden is on the government to demonstrate exigent circumstances.”140140 While other warrantless entries are presumed to be unreasonable, knock and talks are by default permitted. Fourth Amendment jurisprudence already treats knock and talks differently than other warrantless entries of the home.

Additionally, while other exceptions to the warrant requirement depend on fact-specific circumstances and are therefore limited in their applicability, knock and talks enjoy extremely broad authorization. Consider other circumstances where the police may enter the curtilage of the home without a warrant. Police can enter without a warrant to prevent the destruction of evidence.141141

Police in “hot pursuit” of a fleeing felony suspect can also follow the suspect into the home without a warrant.142142 And police can enter without a warrant if they believe someone is injured or in danger.143143 All of these scenarios require an exigency serious enough to overcome the warrant requirement. And this exigency will need to be demonstrated by a fact-driven inquiry. By contrast, the Court has acknowledged that the general “habits of the country” give the police a license to conduct knock and talks.144144

The Supreme Court has also singled out the space of the home as an area which must be protected by bright-line rules. The Fourth Amendment draws a “firm line at the entrance to the house” because “[t]he physical entry of the home is the chief evil against which the wording of the Fourth Amendment is directed.”145145

And in Kyllo v. United States,146146 the Court held that line is “not only firm but also bright.”147147 Prohibiting police from extending a knock and talk beyond the site of the initial knock and talk would be in line with Fourth Amendment objectives.

Because knock and talks are distinct from other exceptions to the warrant requirement, it makes sense to constrain them with bright-line rules. The license to conduct a knock and talk is so much broader in scope than the other exceptions that without clear limits, the knock and talk exception threatens to eclipse the stringent protections that the Fourth Amendment grants.

One potential concern with using bright-line rules to govern knock and talks is that social customs related to knocking on the door are amorphous, leading to police confusion. A knock and talk is theoretically identical to what a private citizen might do, but different private citizens behave differently around someone’s home. While it would be unusual for trick-or-treaters or canvassers to probe around a house after receiving no response at the front door, a friendly neighbor may feel perfectly comfortable heading into the backyard to see if anyone is home. Neighbors on especially good terms may even occasionally let themselves into an unlocked door and walk around inside to see if someone is home. Since there are so many scenarios to consider, it makes it difficult to craft a rule that differentiates between those actions that are covered by the license and those that are not.

This ambiguity could justify using a bright-line rule to determine acceptable behavior. The implied license should not be construed overbroadly simply because a small group of people act as trusted neighbors. The Supreme Court has recognized that a knock and talk is no more than what “any” private citizen can do.148148

Accordingly, the license should be understood as only covering baseline behaviors that are available to all citizens. This consists of approaching an accessible door, knocking, waiting for a response, and leaving at the conclusion. While neighbors could potentially have greater license to approach a home than salesmen, police should not be able to claim a neighborly license. Such a construction would give police greater ability to move around the home than many private citizens and would expand the knock and talk beyond what the implied license permits.

Limiting knock and talks according to bright-line rules would not interfere with legitimate police work. Constraints on knock and talks are counterbalanced by the police’s ability to pursue other strategies, including applying for a warrant. For other exceptions to the warrant requirement, the police do not have time to seek a warrant, so their options are limited. When there are no exigencies, knock and talks are merely one of several investigative strategies the police can pursue.

One potential reason that courts are permissive of meandering police behavior on the curtilage is that there is rarely a sufficient expectation of privacy to give rise to Katz protection. Front and back porches, yards, and driveways are almost always exposed to public view. Even if an area behind the home is not visible from the street, police can constitutionally observe these spaces, even using means of aerial surveillance to do so.149149

Since Katz provides the usual test for violations of the Fourth Amendment, courts may wrongly view impermissible knock and talks as insignificant oversteps of government power. Courts may also find it pointless to restrict police from wandering around the home because they could obtain the same visual information through other means. Nevertheless, when the police physically intrude upon the home without permission, these considerations are irrelevant. In Jones v. United States,150150 another case where the Court utilized a property-based understanding of the Fourth Amendment, the Court held that the physical attachment of a GPS tracker to a car constituted a search.151151 Like in Jardines, the warrantless physical intrusion upon the car to gather information was sufficient to violate the Fourth Amendment, and Katz was therefore irrelevant to the analysis.152152 In Jones, the Court considered it unimportant that there is generally no expectation of privacy on public roads and that the location of a vehicle is considered voluntarily conveyed to the public.153153 Once physical intrusion occurs, a warrant is needed. This is for good reason. As the Court noted, the Fourth Amendment “embod[ies] a particular concern for government trespass upon [enumerated] areas.”154154 The warrant requirement, at the expense of police convenience, ensures that investigations proceed in a justified and constrained manner.

When the courts allow knock and talks to proceed beyond the limits of any implied license or warrant, they enable tactics that can be used for unfettered intimidation. Police can post themselves on a citizen’s doorstep and refuse to leave. They can knock and call for minutes on end or wander around the perimeter of the house. Attempting to hide within the confines of one’s home may simply prolong the harassment. Confoundingly, the police are free to engage in such behavior on a whim, without ever needing to show suspicion.

The right to be free from government intrusion in one’s home is the right “[a]t the very core” of the Fourth Amendment.155155

Rather than legitimizing questionable police knock and talks, courts must stand up to attempts to sidestep the warrant requirement and reaffirm the paramount respect that the Constitution grants to the home.

Following the Supreme Court’s decision in Jardines, courts across the country modified their knock and talk jurisprudence to varying degrees. These ongoing controversies about police authority leave the home, the area most heavily protected by the Fourth Amendment, vulnerable to warrantless intrusion. The Supreme Court’s discussion of knock and talks, though limited, implies consistent and sensible limits on police usage of knock and talks. Courts must analyze these Fourth Amendment issues by considering the implied social license to approach the door of a home and knock.

Several circuits allow police to extend the duration and scope of an attempted knock and talk based on the circumstances that police encounter after beginning the knock and talk, but this cannot be justified. Without an invitation to continue from an occupant, any effort by the police to persist with an unsuccessful knock and talk oversteps the social license that allows the police to be on the curtilage in the first instance.

Adopting clearer and stricter rules is necessary to ensure that police perform knock and talks in a way that comports with the principles of the Fourth Amendment. Additional constraints will not prevent police from conducting ordinary knock and talks, but instead will safeguard against police who abuse this privilege to visit private areas of the home for an extended duration. Through a renewed focus on the implicit license to knock on the door, courts will reaffirm the home’s special status in Fourth Amendment jurisprudence as “first among equals.”156156