The Use of a Drug Detection Dog to Sniff at the Front Door of a House is a Search

by Jack E. Call
Professor of Criminal Justice
Radford University

            The Miami-Dade Police Department received an unconfirmed tip that Jardines was growing marijuana in his home.  Without a search warrant or Jardines’ consent, a team of police officers went to Jardines’ home with a dog trained to detect the odor of narcotics.  As they approached the front porch of the home, the dog reacted in a way that indicated he smelled narcotics.  After pacing back and forth, the dog sat down in front of the front door, indicating that the odor was strongest around the door. 

            Armed with this information, the police obtained a warrant to search Jardines’ home.  When the police executed the warrant, Jardines attempted to flee and was placed in custody.  A search of his home revealed marijuana plants.  The issue in this case, Florida v. Jardines, was whether the use of the dog to sniff at Jardines’ home from his front porch was a search.  On March 26, 2013, the Supreme Court ruled, 5-4, that it was.

The Definition of Search

            The Fourth Amendment to the Constitution protects the “right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.”  Prior to 1967, Supreme Court cases in which the issue was whether a search had occurred focused on the “persons, houses, papers, and effects” language of the Fourth Amendment and concluded that the police search when they physically intrude upon a constitutionally-protected area.  This had led students of the Constitution to conclude that there was no search under the Fourth Amendment unless such a physical intrusion had occurred – an approach sometimes referred to as the trespass doctrine.[1]

            In 1967, the Supreme Court ruled in Katz v. United States[2] that the police had conducted a search when they recorded Katz’ portion of phone conversations that he engaged in from a particular glass enclosed phone booth through the use of a recording device that was attached to the outside of the phone booth.  Katz has long been considered a landmark case because the Court found that the police had searched in this case even though there was no physical intrusion into a constitutionally-protected area, i.e., no violation of the trespass doctrine (since the eavesdropping device was attached to the outside of the phone booth).  Instead, the Court concluded that the Fourth Amendment “protects people, not places,” and the primary interest protected by the amendment is privacy.  The Court ruled that a trespass into a constitutionally-protected area was unnecessary, so long as the police action intruded upon a reasonable expectation of privacy.

            The generally accepted view of the ruling in Katz was that the new reasonable-expectation-of-privacy approach created by that case replaced the old trespass doctrine.  Then the Court decided U.S. v. Jones[3] last year.  In Jones, the Court concluded that attaching a GPS tracking device to a car to assist the police in monitoring the movements of the car was a search [Editor’s Note: U.S. v. Jones is discussed further in a prior issue of this Bulletin – see “Supreme Court Rules on Use of GPS Devices as Searches”].  The most surprising aspect of the Court’s ruling in Jones was that it based its decision on the trespass doctrine, rather than the Katz reasonable-expectation-of-privacy approach.  In so doing, a majority of the Justices made it clear that there are now two ways that police action might be found to be a search under the Fourth Amendment – under the trespass doctrine or the reasonable-expectation-of-privacy approach.

Drug Detection Dogs and the Trespass Doctrine

            In a somewhat unusual alignment of the Court, Justice Scalia wrote the majority opinion in Jardines, joined by Justices Thomas, Ginsburg, Sotomayor, and Kagan.[4]  After reiterating the Court’s conclusion in Jones that the trespass doctrine retains its vitality, even after Katz, Justice Scalia indicated that this case is a relatively easy one under that doctrine.  Regardless of whether it could be concluded that the detection of the odor of illegal drugs by trained dogs does (or does not) invade any privacy expectations, Justice Scalia thought it was unnecessary to address that question.  The drug detection dog in this case detected the odor of marijuana from the front porch of Jardines’ home.  That area is clearly within the curtilage of the home (the area immediately surrounding the home where activities associated with the home commonly take place) and is thus a constitutionally-protected area.  As Justice Scalia stated, “[o]ne virtue of the Fourth Amendment’s property-rights baseline is that it keeps easy cases easy.”

            The more difficult issue concerned whether the officer and his drug detection dog were present in the curtilage with Jardines’ implied consent.  English and American common law has long recognized that residential dwellers extend an invitation to visitors (often referred to as a “license”) “to approach the home by the front path, knock promptly, wait briefly to be received, and then (absent invitation to linger longer) leave.”  Justice Scalia concluded, however, that this invitation does not extend to all purposes that a visitor might have:  “To find a visitor knocking on the door is routine (even if sometimes unwelcome); to spot that same visitor exploring the front path with a metal detector, or marching his bloodhound into the garden before saying hello and asking permission, would inspire most of us to – well, call the police.”  Thus, when the police came to Jardines’ home with a drug detection dog for the purpose of sniffing around the front of his home, it exceeded the scope of this commonly understood invitation to the public.

            Justice Kagan wrote a concurring opinion, joined by Justices Sotomayor and Ginsburg.  They agreed with Justice Scalia that the use of the drug detection dog was a search because it invaded a constitutionally-protected area.  However, they also concluded that this action by the police also intruded upon a reasonable expectation of privacy.  Justice Kagan indicated that:

            “I could just as happily have decided [this case] by looking to Jardines’ privacy interests.  A decision along those lines would have looked … well, much like this one.  It would have talked about the ‘the right of a man to retreat into his own home and there be free from unreasonable governmental intrusion.’ … It would have explained that ‘privacy expectations are most heightened’ in the home and the surrounding area. … And it would have determined that police officers invade those shared expectations when they use trained canine assistants to reveal within the confines of a home what they could not otherwise have found there.”

            The opinion for the four dissenting Justices was written by Justice Alito.  The dissenters concluded that the license to the public to visit the home extends even to persons that the homeowner would prefer not to come (for example, persons soliciting donations or selling magazine subscriptions).  Therefore, when the police come with a drug detection dog, they do not exceed the scope of this license.  The dissenters note that the majority was unable to cite one case in the past 800 years finding that bringing a tracking dog to a person’s front door was a trespass.

            The dissenters also addressed the conclusion of the concurring Justices that use of the drug detection dog also intruded upon a reasonable expectation of privacy.  They concluded that a “reasonable person understands that odors emanating from a house may be detected from locations that are open to the public, and a reasonable person will not count on the strength of those odors remaining within the range that …. cannot be smelled by a human.” 

            The dissenters were careful to distinguish this case from Kyllo v. United States,[5] where the Court ruled that the use of a thermal imaging device from a public street to measure the amount of heat coming from a home was a search.  Critical to the Court’s holding in Kyllo was that the government had used “a device that is not in general public use, to explore details of the home that would previously have been unknowable without physical intrusion.”  The dissenters took issue with the concurring Justices’ conclusion that drug detection dogs are “not in general public use.”  They believed that “Kyllo is best understood as a decision about the use of new technology.”   Since law enforcement officers have been using “dogs’ acute sense of smell” for centuries, the use of dogs in this way is anything but a new technology.

Law Enforcement Implications of Jardines

            The first apparent implication of the Court’s decision in Jardines is that it means the police must have a search warrant before taking a drug detection dog to a suspect’s home to sniff for drugs within the curtilage of the home.  That is a reasonable and prudent conclusion to draw, but it bears mentioning that this is not what the Court held in Jardines.  The Court’s holding in the case is that the use of the dog to sniff drugs just outside the home is a search. 

            The Court has also (generally) taken the position that the Fourth Amendment is properly interpreted as including a preference for warrants.  However, there are many exceptions to this warrant requirement.  Jardines does not consider whether any of those exceptions (or perhaps a newly-created exception) applies to the situation facing the police in that case.  It seems likely that the Court will find that the police need a search warrant before using a drug detection dog to sniff at a suspect’s front door, but until it specifically rules on that issue, it cannot be said with complete confidence that this is the rule.  Given the uncertainty that exists, then, the prudent action would be to obtain the search warrant. 

            Of course, the problem that this creates for the police is more than just the inconvenience involved in obtaining a warrant.  If the use of the drug detection dog in Jardines were not a search, the police could go to a suspect’s home with a dog based simply on a hunch that drugs would be found.  However, if a warrant is required, then obviously the police need probable cause to think that drugs are present in the house.  Since in Jardines the police apparently possessed nothing more than an unverified tip (the source of which is unclear from the facts given in the opinion), it is quite unlikely that they possessed a sufficient basis for a warrant.

            Some of the language used in the opinions in Jardines raises another interesting issue.  When I teach the subject of what constitutes a search in my constitutional rights classes, I use the example of a police officer who goes to a suspect’s home (without a warrant) to simply knock and see if the suspect is at home.  (The opinions in Jardines refer to this as a “knock and talk”).  When the officer arrives, he finds the front door open and sees contraband sitting on a coffee table a few feet inside the house.  This observation is not a search because any member of the public is free to go to the suspect’s front door (in accordance with the license referred to in the Jardines opinions).

            Let’s assume the front door is not open, and no one answers when the police knock on the front door.  There is a window five feet to the right of the door.  The officer moves in front of the window, looks inside to see if anyone is coming, and observes the contraband on the coffee table.  I have taught that this is probably not a search either, because it is common for visitors to look inside a window so close to the front door if no one answers a knock on the door (thus the resident cannot reasonably expect to be free from such observations).

            Some language in Jardines casts some doubt on what I have been teaching my students.  In footnote 3 of the Court’s opinion, Justice Scalia states “[w]e think a typical person would find it ‘a cause for great alarm’ …. to find a stranger snooping about his front porch with or without a dog.”  (Emphasis in the original).  More directly on point is Justice Alito’s statement in the dissenting opinion that “[t]here is no such thing as squatter’s rights on a front porch.  A stranger may not plop down uninvited to spend the afternoon in the front porch rocking chair, or throw down a sleeping bag to spend the night, or lurk on the front porch looking in the windows.”  (My emphasis). 

            At least one lower court has already seen significance to this language.  In Powell v. Florida,[6] a law enforcement officer knocked at the front door of Powell’s mobile home, walked down the two or three steps to the front door when no one answered, and looked into the home through a window two feet from the front door.  A Florida Court of Appeal held that peering into the window was a search.  It seemed important to the court, however, that the officer had to walk down those few steps from the front door before he looked into the window.  Anticipating a situation similar to the one we have just hypothesized, the court indicated that “[u]nder certain circumstances, implicit permission may exist to look through an un-curtained window while standing on a front porch momentarily to see whether the resident is approaching the door, assuming no unreasonable means or devices are used.” 

            As with so many Supreme Court opinions, Jardines resolves a very important and common situation.  But also like so many opinions, the full implications of the opinion remain to be seen.

[1] See Orin Kerr, “The Curious History of Fourth Amendment Searches” (, retrieved 5/27/2012), for an article that argues that there never was a trespass doctrine under the Fourth Amendment.

[2] 389 U.S. 347 (1967).

[3] 132 S. Ct. 945 (2012).

[4] Justices Scalia and Thomas do not typically come down on the side of defendants in criminal cases decided by the Court.

[5] 533 U.S. 27 (2001).

[6] 2013 Fla. App. LEXIS 8166 (Ct. App, 1st Dist.).

Disclaimer:  The content of the Virginia Police Legal Bulletin does not constitute legal advice, nor does it reflect the opinions or views of the Virginia Police Legal Advisors Committee.