Opinion

Florida v. Jardines

  • 569 U.S. 1
  • 24 Fla. L. Weekly Fed. S 117
  • 81 U.S.L.W. 4209
  • 133 S. Ct. 1409
  • 185 L. Ed. 2d 495
Court
Supreme Court of the United States
Filed
Mar 26, 2013
Status
Published
Author
Scalia
On the bench
Scalia
Cited by
1,497 cases
Authority
More cited than 99.7%

Questioned by United States v. Ponce, 734 F.3d 1225 (2013)

holding that an "implicit [public] license typically permits [a] visitor to approach the home by the front path, knock promptly, wait briefly to be received, and then (absent invitation to linger longer) leave. Complying with the terms of that traditional invitation does not require fine-grained legal knowledge; it is generally managed without incident by the Nation's Girl Scouts and trick-or-treaters. Thus, a police officer not armed with a warrant may approach a home and knock, precisely because that is no more than any private citizen might do"

How later courts described this case

  • holding that an "implicit [public] license typically permits [a] visitor to approach the home by the front path, knock promptly, wait briefly to be received, and then (absent invitation to linger longer) leave. Complying with the terms of that traditional invitation does not require fine-grained legal knowledge; it is generally managed without incident by the Nation's Girl Scouts and trick-or-treaters. Thus, a police officer not armed with a warrant may approach a home and knock, precisely because that is no more than any private citizen might do"
  • explaining that “the home is first among equals,” that “the right of a man to retreat into his own home” stands at the Fourth Amendment’s “very core,” and that “[t]his right would be of little practical value if the State’s agents could stand in a home’s porch or side garden,” or “just outside the front window,” and “trawl for evidence with impunity” (emphasis added and internal quotation marks omitted)
  • recognizing that, under the Fourth Amendment, “the home is first among equals” of constitutionally protected spaces, and that the constitutional protection given to the home was violated when law enforcement “gathered ... information by physically entering and occupying the [curtilage of the home] to engage in conduct not explicitly or implicitly permitted by the homeowner”
  • stating that, for a home’s occupant “[t]o find a visitor knocking on the door is routine,” but that “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 exceed an implicit license to approach the front door and conduct a knock and talk.

Written by the judges who cited it.

Later courts went against this

  • Questioned by United States v. Ponce, 734 F.3d 1225 (2013)

    — U.S.-, 133 S.Ct. 1409, 185 L.Ed.2d 495 (2013), which the Supreme Court issued almost two years after this dog sniff occurred, may call into question the application of some of our precedent that touches on this issue, and this court has not had the benefit of
    Court of Appeals for the Tenth CircuitOct 30, 2013Read it

Distinguished

  • Distinguished by McNerney v. Rescap Borrower Claims Trust (In re Residential Capital, LLC), 563 B.R. 477 (2016)

    But the cases on which McNerney relies, which involve the Fourth Amendment of the United States Constitution, see McNerney Reply Br. at 11 (citing, for example, Florida v. Jardines, — U.S.-, 133 S.Ct. 1409, 185 L.Ed.2d 495 (2013)), are inapposite.
    District Court, S.D. New YorkNov 30, 2016Read it
  • Distinguished by STATE OF MISSOURI, Plaintiff-Respondent v. ANGELA MEGAN GUINN, 2014 Mo. App. LEXIS 1351 (2014)

    ” Id. at 1416. Jardines is inapplicable to this case because Defendant does not contend that any officer engaged in any type of illegal search before knocking on her door and asking permission to enter.
    Missouri Court of AppealsDec 4, 2014Read it
  • Distinguished by United States v. Dana Jackson, 728 F.3d 367 (2013)

    ” It also maintains that the district court correctly held that the trash can’s location was outside the apartment’s curtilage and that, because the officers did not enter the cur-tilage, Jardines is inapplicable.
    Court of Appeals for the Fourth CircuitAug 26, 2013Read it

The opinion

(Slip Opinion) OCTOBER TERM, 2012 1

Syllabus

NOTE: Where it is feasible, a syllabus (headnote) will be released, as is

being done in connection with this case, at the time the opinion is issued.

The syllabus constitutes no part of the opinion of the Court but has been

prepared by the Reporter of Decisions for the convenience of the reader.

See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.

SUPREME COURT OF THE UNITED STATES

Syllabus

FLORIDA v. JARDINES

CERTIORARI TO THE SUPREME COURT OF FLORIDA

No. 11–564. Argued October 31, 2012—Decided March 26, 2013

Police took a drug-sniffing dog to Jardines’ front porch, where the dog

gave a positive alert for narcotics. Based on the alert, the officers ob-

tained a warrant for a search, which revealed marijuana plants;

Jardines was charged with trafficking in cannabis. The Supreme

Court of Florida approved the trial court’s decision to suppress the

evidence, holding that the officers had engaged in a Fourth Amend-

ment search unsupported by probable cause.

Held: The investigation of Jardines’ home was a “search” within the

meaning of the Fourth Amendment. Pp. 3–10.

(a) When “the Government obtains information by physically in-

truding” on persons, houses, papers, or effects, “a ‘search’ within the

original meaning of the Fourth Amendment” has “undoubtedly oc-

curred.” United States v. Jones, 565 U. S. ___, ___, n. 3. Pp. 3–4.

(b) At the Fourth Amendment’s “very core” stands “the right of a

man to retreat into his own home and there be free from unreason-

able governmental intrusion.” Silverman v. United States, 365 U. S.

505, 511. The area “immediately surrounding and associated with

the home”—the curtilage—is “part of the home itself for Fourth

Amendment purposes.” Oliver v. United States, 466 U. S. 170, 180.

The officers entered the curtilage here: The front porch is the classic

exemplar of an area “to which the activity of home life extends.” Id.,

at 182, n. 12. Pp. 4–5.

(c) The officers’ entry was not explicitly or implicitly invited. Offi-

cers need not “shield their eyes” when passing by a home “on public

thoroughfares,” California v. Ciraolo, 476 U. S. 207, 213, but “no man

can set his foot upon his neighbour’s close without his leave,” Entick

v. Carrington, 2 Wils. K. B. 275, 291, 95 Eng. Rep. 807, 817. A police

officer not armed with a warrant may approach a home in hopes of

speaking to its occupants, because that is “no more than any private

2 FLORIDA v. JARDINES

Syllabus

citizen might do.” Kentucky v. King, 563 U. S. ___, ___. But the scope

of a license is limited not only to a particular area but also to a specif-

ic purpose, and there is no customary invitation to enter the curtilage

simply to conduct a search. Pp. 5–8.

(d) It is unnecessary to decide whether the officers violated

Jardines’ expectation of privacy under Katz v. United States, 389

U. S. 347. Pp. 8–10.

73 So. 3d 34, affirmed.

SCALIA, J., delivered the opinion of the Court, in which THOMAS,

GINSBURG, SOTOMAYOR, and KAGAN, JJ., joined. KAGAN, J., filed a con-

curring opinion, in which GINSBURG and SOTOMAYOR, JJ., joined. ALITO,

J., filed a dissenting opinion, in which ROBERTS, C. J., and KENNEDY

and BREYER, JJ., joined.

Cite as: 569 U. S. ____ (2013) 1

Opinion of the Court

NOTICE: This opinion is subject to formal revision before publication in the

preliminary print of the United States Reports. Readers are requested to

notify the Reporter of Decisions, Supreme Court of the United States, Wash-

ington, D. C. 20543, of any typographical or other formal errors, in order

that corrections may be made before the preliminary print goes to press.

SUPREME COURT OF THE UNITED STATES

_________________

No. 11–564

_________________

FLORIDA, PETITIONER v. JOELIS JARDINES

ON WRIT OF CERTIORARI TO THE SUPREME COURT OF

FLORIDA

[March 26, 2013]

JUSTICE SCALIA delivered the opinion of the Court.

We consider whether using a drug-sniffing dog on a

homeowner’s porch to investigate the contents of the

home is a “search” within the meaning of the Fourth

Amendment.

I

In 2006, Detective William Pedraja of the Miami-Dade

Police Department received an unverified tip that mari-

juana was being grown in the home of respondent Joelis

Jardines. One month later, the Department and the

Drug Enforcement Administration sent a joint surveillance

team to Jardines’ home. Detective Pedraja was part of

that team. He watched the home for fifteen minutes and

saw no vehicles in the driveway or activity around the

home, and could not see inside because the blinds were

drawn. Detective Pedraja then approached Jardines’

home accompanied by Detective Douglas Bartelt, a trained

canine handler who had just arrived at the scene with his

drug-sniffing dog. The dog was trained to detect the scent

of marijuana, cocaine, heroin, and several other drugs,

indicating the presence of any of these substances through

particular behavioral changes recognizable by his handler.

2 FLORIDA v. JARDINES

Opinion of the Court

Detective Bartelt had the dog on a six-foot leash, owing

in part to the dog’s “wild” nature, App. to Pet. for Cert. A–

35, and tendency to dart around erratically while search-

ing. As the dog approached Jardines’ front porch, he

apparently sensed one of the odors he had been trained to

detect, and began energetically exploring the area for the

strongest point source of that odor. As Detective Bartelt

explained, the dog “began tracking that airborne odor by

. . . tracking back and forth,” engaging in what is called

“bracketing,” “back and forth, back and forth.” Id., at A–

33 to A–34. Detective Bartelt gave the dog “the full six

feet of the leash plus whatever safe distance [he could]

give him” to do this—he testified that he needed to give

the dog “as much distance as I can.” Id., at A–35. And

Detective Pedraja stood back while this was occurring, so

that he would not “get knocked over” when the dog was

“spinning around trying to find” the source. Id., at A–38.

After sniffing the base of the front door, the dog sat,

which is the trained behavior upon discovering the odor’s

strongest point. Detective Bartelt then pulled the dog

away from the door and returned to his vehicle. He left

the scene after informing Detective Pedraja that there had

been a positive alert for narcotics.

On the basis of what he had learned at the home, De-

tective Pedraja applied for and received a warrant to

search the residence. When the warrant was executed later

that day, Jardines attempted to flee and was arrested; the

search revealed marijuana plants, and he was charged

with trafficking in cannabis.

At trial, Jardines moved to suppress the marijuana

plants on the ground that the canine investigation was an

unreasonable search. The trial court granted the motion,

and the Florida Third District Court of Appeal reversed.

On a petition for discretionary review, the Florida Su-

preme Court quashed the decision of the Third District

Court of Appeal and approved the trial court’s decision to

Cite as: 569 U. S. ____ (2013) 3

Opinion of the Court

suppress, holding (as relevant here) that the use of the

trained narcotics dog to investigate Jardines’ home was

a Fourth Amendment search unsupported by probable

cause, rendering invalid the warrant based upon infor-

mation gathered in that search. 73 So. 3d 34 (2011).

We granted certiorari, limited to the question of whether

the officers’ behavior was a search within the meaning of

the Fourth Amendment. 565 U. S. ___ (2012).

II

The Fourth Amendment provides in relevant part that

the “right of the people to be secure in their persons, houses,

papers, and effects, against unreasonable searches and

seizures, shall not be violated.” The Amendment estab-

lishes a simple baseline, one that for much of our history

formed the exclusive basis for its protections: When “the

Government obtains information by physically intruding”

on persons, houses, papers, or effects, “a ‘search’ within

the original meaning of the Fourth Amendment” has “un-

doubtedly occurred.” United States v. Jones, 565 U. S.

___, ___, n. 3 (2012) (slip op., at 6, n. 3). By reason of

our decision in Katz v. United States, 389 U. S. 347

(1967), property rights “are not the sole measure of Fourth

Amendment violations,” Soldal v. Cook County, 506 U. S.

56, 64 (1992)—but though Katz may add to the baseline, it

does not subtract anything from the Amendment’s protec-

tions “when the Government does engage in [a] physi-

cal intrusion of a constitutionally protected area,” United

States v. Knotts, 460 U. S. 276, 286 (1983) (Brennan, J.,

concurring in the judgment).

That principle renders this case a straightforward one.

The officers were gathering information in an area belong-

ing to Jardines and immediately surrounding his house—

in the curtilage of the house, which we have held enjoys

protection as part of the home itself. And they gathered

that information by physically entering and occupying the

4 FLORIDA v. JARDINES

Opinion of the Court

area to engage in conduct not explicitly or implicitly per-

mitted by the homeowner.

A

The Fourth Amendment “indicates with some precision

the places and things encompassed by its protections”:

persons, houses, papers, and effects. Oliver v. United

States, 466 U. S. 170, 176 (1984). The Fourth Amendment

does not, therefore, prevent all investigations conducted

on private property; for example, an officer may (subject to

Katz) gather information in what we have called “open

fields”—even if those fields are privately owned—because

such fields are not enumerated in the Amendment’s text.

Hester v. United States, 265 U. S. 57 (1924).

But when it comes to the Fourth Amendment, the home

is first among equals. 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 in-

trusion.” Silverman v. United States, 365 U. S. 505, 511

(1961). This right would be of little practical value if the

State’s agents could stand in a home’s porch or side gar-

den and trawl for evidence with impunity; the right to

retreat would be significantly diminished if the police

could enter a man’s property to observe his repose from

just outside the front window.

We therefore regard the area “immediately surrounding

and associated with the home”—what our cases call the

curtilage—as “part of the home itself for Fourth Amend-

ment purposes.” Oliver, supra, at 180. That principle has

ancient and durable roots. Just as the distinction between

the home and the open fields is “as old as the common

law,” Hester, supra, at 59, so too is the identity of home

and what Blackstone called the “curtilage or homestall,”

for the “house protects and privileges all its branches and

appurtenants.” 4 W. Blackstone, Commentaries on the

Laws of England 223, 225 (1769). This area around the

Cite as: 569 U. S. ____ (2013) 5

Opinion of the Court

home is “intimately linked to the home, both physically

and psychologically,” and is where “privacy expectations

are most heightened.” California v. Ciraolo, 476 U. S. 207,

213 (1986).

While the boundaries of the curtilage are generally

“clearly marked,” the “conception defining the curtilage” is

at any rate familiar enough that it is “easily understood

from our daily experience.” Oliver, 466 U. S., at 182, n. 12.

Here there is no doubt that the officers entered it: The

front porch is the classic exemplar of an area adjacent to

the home and “to which the activity of home life extends.”

Ibid.

B

Since the officers’ investigation took place in a constitu-

tionally protected area, we turn to the question of whether

it was accomplished through an unlicensed physical in-

trusion.1 While law enforcement officers need not “shield

their eyes” when passing by the home “on public thorough-

fares,” Ciraolo, 476 U. S., at 213, an officer’s leave to

gather information is sharply circumscribed when he steps

off those thoroughfares and enters the Fourth Amend-

ment’s protected areas. In permitting, for example, visual

observation of the home from “public navigable airspace,”

we were careful to note that it was done “in a physically

nonintrusive manner.” Ibid. Entick v. Carrington, 2 Wils.

K. B. 275, 95 Eng. Rep. 807 (K. B. 1765), a case “undoubt-

edly familiar” to “every American statesman” at the time

of the Founding, Boyd v. United States, 116 U. S. 616, 626

——————

1 At oral argument, the State and its amicus the Solicitor General

argued that Jardines conceded in the lower courts that the officers had

a right to be where they were. This misstates the record. Jardines

conceded nothing more than the unsurprising proposition that the of-

ficers could have lawfully approached his home to knock on the front

door in hopes of speaking with him. Of course, that is not what they

did.

6 FLORIDA v. JARDINES

Opinion of the Court

(1886), states the general rule clearly: “[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.” 2 Wils.

K. B., at 291, 95 Eng. Rep., at 817. As it is undisputed

that the detectives had all four of their feet and all four of

their companion’s firmly planted on the constitutionally

protected extension of Jardines’ home, the only question is

whether he had given his leave (even implicitly) for them

to do so. He had not.

“A license may be implied from the habits of the coun-

try,” notwithstanding the “strict rule of the English com-

mon law as to entry upon a close.” McKee v. Gratz, 260

U. S. 127, 136 (1922) (Holmes, J.). We have accordingly

recognized that “the knocker on the front door is treated

as an invitation or license to attempt an entry, justifying

ingress to the home by solicitors, hawkers and peddlers

of all kinds.” Breard v. Alexandria, 341 U. S. 622, 626

(1951). This 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. Complying with the terms of that

traditional invitation does not require fine-grained legal

knowledge; it is generally managed without incident by

the Nation’s Girl Scouts and trick-or-treaters.2 Thus, a

police officer not armed with a warrant may approach a

home and knock, precisely because that is “no more than

any private citizen might do.” Kentucky v. King, 563 U. S.

——————

2 With this much, the dissent seems to agree—it would inquire into

“ ‘the appearance of things,’ ” post, at 5 (opinion of ALITO, J.), what is

“typica[l]” for a visitor, ibid., what might cause “alarm” to a “resident of

the premises,” ibid., what is “expected” of “ordinary visitors,” ibid., and

what would be expected from a “ ‘reasonably respectful citizen,’ ” post, at

7. These are good questions. But their answers are incompatible with

the dissent’s outcome, which is presumably why the dissent does not

even try to argue that it would be customary, usual, reasonable, re-

spectful, ordinary, typical, nonalarming, etc., for a stranger to explore

the curtilage of the home with trained drug dogs.

Cite as: 569 U. S. ____ (2013) 7

Opinion of the Court

___, ___ (2011) (slip op., at 16).

But introducing a trained police dog to explore the area

around the home in hopes of discovering incriminating

evidence is something else. There is no customary invita-

tion to do that. An invitation to engage in canine forensic

investigation assuredly does not inhere in the very act of

hanging a knocker.3 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 detec-

tor, or marching his bloodhound into the garden before

saying hello and asking permission, would inspire most

of us to—well, call the police. The scope of a license—

express or implied—is limited not only to a particular area

but also to a specific purpose. Consent at a traffic stop to

an officer’s checking out an anonymous tip that there is a

body in the trunk does not permit the officer to rummage

through the trunk for narcotics. Here, the background

social norms that invite a visitor to the front door do not

invite him there to conduct a search.4

——————

3 The dissent insists that our argument must rest upon “the particu-

lar instrument that Detective Bartelt used to detect the odor of mari-

juana”—the dog. Post, at 8. It is not the dog that is the problem, but the

behavior that here involved use of the dog. We think a typical person

would find it “ ‘a cause for great alarm’ ” (the kind of reaction the dis-

sent quite rightly relies upon to justify its no-night-visits rule, post,

at 5) to find a stranger snooping about his front porch with or without

a dog. The dissent would let the police do whatever they want by way

of gathering evidence so long as they stay on the base-path, to use a

baseball analogy—so long as they “stick to the path that is typically

used to approach a front door, such as a paved walkway.” Ibid. From

that vantage point they can presumably peer into the house through

binoculars with impunity. That is not the law, as even the State con-

cedes. See Tr. of Oral Arg. 6.

4 The dissent argues, citing King, that “gathering evidence—even

damning evidence—is a lawful activity that falls within the scope of the

license to approach.” Post, at 7. That is a false generalization. What

King establishes is that it is not a Fourth Amendment search to ap-

proach the home in order to speak with the occupant, because all are

8 FLORIDA v. JARDINES

Opinion of the Court

The State points to our decisions holding that the sub-

jective intent of the officer is irrelevant. See Ashcroft v.

al-Kidd, 563 U. S. ___ (2011); Whren v. United States, 517

U. S. 806 (1996). But those cases merely hold that a stop

or search that is objectively reasonable is not vitiated by

the fact that the officer’s real reason for making the stop

or search has nothing to do with the validating reason.

Thus, the defendant will not be heard to complain that

although he was speeding the officer’s real reason for the

stop was racial harassment. See id., at 810, 813. Here,

however, the question before the court is precisely whether

the officer’s conduct was an objectively reasonable search.

As we have described, that depends upon whether the

officers had an implied license to enter the porch, which in

turn depends upon the purpose for which they entered.

Here, their behavior objectively reveals a purpose to con-

duct a search, which is not what anyone would think he

had license to do.

III

The State argues that investigation by a forensic narcot-

ics dog by definition cannot implicate any legitimate pri-

vacy interest. The State cites for authority our decisions

in United States v. Place, 462 U. S. 696 (1983), United

States v. Jacobsen, 466 U. S. 109 (1984), and Illinois v.

Caballes, 543 U. S. 405 (2005), which held, respectively,

that canine inspection of luggage in an airport, chemical

testing of a substance that had fallen from a parcel in

transit, and canine inspection of an automobile during a

lawful traffic stop, do not violate the “reasonable expecta-

tion of privacy” described in Katz.

——————

invited to do that. The mere “purpose of discovering information,” post,

at 8, in the course of engaging in that permitted conduct does not cause

it to violate the Fourth Amendment. But no one is impliedly invited to

enter the protected premises of the home in order to do nothing but

conduct a search.

Cite as: 569 U. S. ____ (2013) 9

Opinion of the Court

Just last Term, we considered an argument much like

this. Jones held that tracking an automobile’s where-

abouts using a physically-mounted GPS receiver is a Fourth

Amendment search. The Government argued that the

Katz standard “show[ed] that no search occurred,” as the

defendant had “no ‘reasonable expectation of privacy’ ” in

his whereabouts on the public roads, Jones, 565 U. S., at

___ (slip op., at 5)—a proposition with at least as much

support in our case law as the one the State marshals

here. See, e.g., United States v. Knotts, 460 U. S. 276, 278

(1983). But because the GPS receiver had been physically

mounted on the defendant’s automobile (thus intruding on

his “effects”), we held that tracking the vehicle’s move-

ments was a search: a person’s “Fourth Amendment rights

do not rise or fall with the Katz formulation.” Jones,

supra, at ___ (slip op., at 5). The Katz reasonable-

expectations test “has been added to, not substituted

for,” the traditional property-based understanding of the

Fourth Amendment, and so is unnecessary to consider

when the government gains evidence by physically intrud-

ing on constitutionally protected areas. Jones, supra, at

___ (slip op., at 8).

Thus, we need not decide whether the officers’ investiga-

tion of Jardines’ home violated his expectation of privacy

under Katz. One virtue of the Fourth Amendment’s

property-rights baseline is that it keeps easy cases easy.

That the officers learned what they learned only by physi-

cally intruding on Jardines’ property to gather evidence is

enough to establish that a search occurred.

For a related reason we find irrelevant the State’s ar-

gument (echoed by the dissent) that forensic dogs have

been commonly used by police for centuries. This argu-

ment is apparently directed to our holding in Kyllo v.

United States, 533 U. S. 27 (2001), that surveillance of

the home is a search where “the Government uses a device

that is not in general public use” to “explore details of the

10 FLORIDA v. JARDINES

Opinion of the Court

home that would previously have been unknowable with-

out physical intrusion.” Id., at 40 (emphasis added). But

the implication of that statement (inclusio unius est exclu-

sio alterius) is that when the government uses a physical

intrusion to explore details of the home (including its

curtilage), the antiquity of the tools that they bring along

is irrelevant.

* * *

The government’s use of trained police dogs to inves-

tigate the home and its immediate surroundings is a

“search” within the meaning of the Fourth Amendment.

The judgment of the Supreme Court of Florida is therefore

affirmed.

It is so ordered.

Cite as: 569 U. S. ____ (2013) 1

KAGAN, J., concurring

SUPREME COURT OF THE UNITED STATES

_________________

No. 11–564

_________________

FLORIDA, PETITIONER v. JOELIS JARDINES

ON WRIT OF CERTIORARI TO THE SUPREME COURT OF

FLORIDA

[March 26, 2013]

JUSTICE KAGAN, with whom JUSTICE GINSBURG and

JUSTICE SOTOMAYOR join, concurring.

For me, a simple analogy clinches this case—and does

so on privacy as well as property grounds. A stranger

comes to the front door of your home carrying super-high-

powered binoculars. See ante, at 7, n. 3. He doesn’t knock

or say hello. Instead, he stands on the porch and uses the

binoculars to peer through your windows, into your home’s

furthest corners. It doesn’t take long (the binoculars are

really very fine): In just a couple of minutes, his uncom-

mon behavior allows him to learn details of your life you

disclose to no one. Has your “visitor” trespassed on your

property, exceeding the license you have granted to mem-

bers of the public to, say, drop off the mail or distribute

campaign flyers? Yes, he has. And has he also invaded

your “reasonable expectation of privacy,” by nosing into

intimacies you sensibly thought protected from disclosure?

Katz v. United States, 389 U. S. 347, 360 (1967) (Harlan,

J., concurring). Yes, of course, he has done that too.

That case is this case in every way that matters. Here,

police officers came to Joelis Jardines’ door with a super-

sensitive instrument, which they deployed to detect things

inside that they could not perceive unassisted. The equip-

ment they used was animal, not mineral. But contra the

dissent, see post, at 2 (opinion of ALITO, J.) (noting the

ubiquity of dogs in American households), that is of no

2 FLORIDA v. JARDINES

KAGAN, J., concurring

significance in determining whether a search occurred.

Detective Bartelt’s dog was not your neighbor’s pet, come

to your porch on a leisurely stroll. As this Court discussed

earlier this Term, drug-detection dogs are highly trained

tools of law enforcement, geared to respond in distinctive

ways to specific scents so as to convey clear and reliable

information to their human partners. See Florida v.

Harris, 568 U. S. ___ (2013) (slip op. at 2–3, 7–8). They

are to the poodle down the street as high-powered binocu-

lars are to a piece of plain glass. Like the binoculars, a

drug-detection dog is a specialized device for discovering

objects not in plain view (or plain smell). And as in the

hypothetical above, that device was aimed here at a

home—the most private and inviolate (or so we expect) of

all the places and things the Fourth Amendment protects.

Was this activity a trespass? Yes, as the Court holds to-

day. Was it also an invasion of privacy? Yes, that as well.

The Court today treats this case under a property ru-

bric; I write separately to note that I could just as happily

have decided it 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 right

of a man to retreat into his own home and there be free

from unreasonable governmental intrusion.’ ” Ante, at 4

(quoting Silverman v. United States, 365 U. S. 505, 511

(1961)). It would have insisted on maintaining the “prac-

tical value” of that right by preventing police officers from

standing in an adjacent space and “trawl[ing] for evidence

with impunity.” Ante, at 4. It would have explained that

“ ‘privacy expectations are most heightened’ ” in the home

and the surrounding area. Ante, at 4–5 (quoting Califor-

nia v. Ciraolo, 476 U. S. 207, 213 (1986)). 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. See ante, at 6–7, and nn. 2–3.

Cite as: 569 U. S. ____ (2013) 3

KAGAN, J., concurring

It is not surprising that in a case involving a search of a

home, property concepts and privacy concepts should so

align. The law of property “naturally enough influence[s]”

our “shared social expectations” of what places should be

free from governmental incursions. Georgia v. Randolph,

547 U. S. 103, 111 (2006); see Rakas v. Illinois, 439 U. S.

128, 143, n. 12 (1978). And so the sentiment “my home is

my own,” while originating in property law, now also

denotes a common understanding—extending even beyond

that law’s formal protections—about an especially private

sphere. Jardines’ home was his property; it was also his

most intimate and familiar space. The analysis proceed-

ing from each of those facts, as today’s decision reveals,

runs mostly along the same path.

I can think of only one divergence: If we had decided

this case on privacy grounds, we would have realized that

Kyllo v. United States, 533 U. S. 27 (2001), already re-

solved it.1 The Kyllo Court held that police officers con-

ducted a search when they used a thermal-imaging device

to detect heat emanating from a private home, even

though they committed no trespass. Highlighting our

intention to draw both a “firm” and a “bright” line at “the

entrance to the house,” id., at 40, we announced the fol-

lowing rule:

“Where, as here, the Government uses a device that is

not in general public use, to explore details of the

home that would previously have been unknowable

——————

1 The dissent claims, alternatively, that Illinois v. Caballes, 543 U. S.

405, 409–410 (2005), controls this case (or nearly does). See post, at 9,

11. But Caballes concerned a drug-detection dog’s sniff of an automo-

bile during a traffic stop. See also Florida v. Harris, 568 U. S. ___

(2013). And we have held, over and over again, that people’s expecta-

tions of privacy are much lower in their cars than in their homes. See,

e.g., Arizona v. Gant, 556 U. S. 332, 345 (2009); Wyoming v. Houghton,

526 U. S. 295, 303 (1999); New York v. Class, 475 U. S. 106, 115 (1986);

Cardwell v. Lewis, 417 U. S. 583, 590–591 (1974) (plurality opinion).

4 FLORIDA v. JARDINES

KAGAN, J., concurring

without physical intrusion, the surveillance is a

‘search’ and is presumptively unreasonable without a

warrant.” Ibid.

That “firm” and “bright” rule governs this case: The police

officers here conducted a search because they used a

“device . . . not in general public use” (a trained drug-

detection dog) to “explore details of the home” (the pres-

ence of certain substances) that they would not otherwise

have discovered without entering the premises.

And again, the dissent’s argument that the device is just

a dog cannot change the equation. As Kyllo made clear,

the “sense-enhancing” tool at issue may be “crude” or

“sophisticated,” may be old or new (drug-detection dogs

actually go back not “12,000 years” or “centuries,” post, at

2, 8, 12, but only a few decades), may be either smaller or

bigger than a breadbox; still, “at least where (as here)” the

device is not “in general public use,” training it on a home

violates our “minimal expectation of privacy”—an expecta-

tion “that exists, and that is acknowledged to be reasona-

ble.” 533 U. S., at 34, 36.2 That does not mean the device

——————

2 The

dissent’s other principal reason for concluding that no violation

of privacy occurred in this case—that police officers themselves might

detect an aroma wafting from a house—works no better. If officers can

smell drugs coming from a house, they can use that information; a

human sniff is not a search, we can all agree. But it does not follow

that a person loses his expectation of privacy in the many scents within

his home that (his own nose capably tells him) are not usually detecti-

ble by humans standing outside. And indeed, Kyllo already decided as

much. In response to an identical argument from the dissent in that

case, see 533 U. S., at 43 (Stevens, J., dissenting) (noting that humans

can sometimes detect “heat emanating from a building”), the Kyllo

Court stated: “The dissent’s comparison of the thermal imaging to

various circumstances in which outside observers might be able to

perceive, without technology, the heat of the home . . . is quite irrele-

vant. The fact that equivalent information could sometimes be ob-

tained by other means does not make lawful the use of means that

violate the Fourth Amendment. . . . In any event, [at the time in

question,] no outside observer could have discerned the relative heat of

Cite as: 569 U. S. ____ (2013) 5

KAGAN, J., concurring

is off-limits, as the dissent implies, see post, at 11–12; it

just means police officers cannot use it to examine a home

without a warrant or exigent circumstance. See Brigham

City v. Stuart, 547 U. S. 398, 403–404 (2006) (describing

exigencies allowing the warrantless search of a home).

With these further thoughts, suggesting that a focus on

Jardines’ privacy interests would make an “easy cas[e]

easy” twice over, ante, at 9, I join the Court’s opinion in

full.

——————

Kyllo’s home without thermal imaging.” Id., at 35, n. 2.

Cite as: 569 U. S. ____ (2013) 1

ALITO, J., dissenting

SUPREME COURT OF THE UNITED STATES

_________________

No. 11–564

_________________

FLORIDA, PETITIONER v. JOELIS JARDINES

ON WRIT OF CERTIORARI TO THE SUPREME COURT OF

FLORIDA

[March 26, 2013]

JUSTICE ALITO, with whom THE CHIEF JUSTICE, JUS-

TICE KENNEDY, and JUSTICE BREYER join, dissenting.

The Court’s decision in this important Fourth Amend-

ment case is based on a putative rule of trespass law that

is nowhere to be found in the annals of Anglo-American

jurisprudence.

The law of trespass generally gives members of the

public a license to use a walkway to approach the front

door of a house and to remain there for a brief time. This

license is not limited to persons who intend to speak to an

occupant or who actually do so. (Mail carriers and persons

delivering packages and flyers are examples of individuals

who may lawfully approach a front door without intending

to converse.) Nor is the license restricted to categories

of visitors whom an occupant of the dwelling is likely to

welcome; as the Court acknowledges, this license applies

even to “solicitors, hawkers and peddlers of all kinds.”

Ante, at 6 (internal quotation marks omitted). And the

license even extends to police officers who wish to gather

evidence against an occupant (by asking potentially in-

criminating questions).

According to the Court, however, the police officer in

this case, Detective Bartelt, committed a trespass because

he was accompanied during his otherwise lawful visit to

the front door of respondent’s house by his dog, Franky.

Where is the authority evidencing such a rule? Dogs have

2 FLORIDA v. JARDINES

ALITO, J., dissenting

been domesticated for about 12,000 years;1 they were

ubiquitous in both this country and Britain at the time of

the adoption of the Fourth Amendment;2 and their acute

sense of smell has been used in law enforcement for centu-

ries.3 Yet the Court has been unable to find a single

case—from the United States or any other common-law

nation—that supports the rule on which its decision is

based. Thus, trespass law provides no support for the

Court’s holding today.

The Court’s decision is also inconsistent with the

reasonable-expectations-of-privacy test that the Court

adopted in Katz v. United States, 389 U. S. 347 (1967). 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,

while detectible by a dog, cannot be smelled by a human.

For these reasons, I would hold that no search within

the meaning of the Fourth Amendment took place in this

case, and I would reverse the decision below.

I

The opinion of the Court may leave a reader with the

mistaken impression that Detective Bartelt and Franky

remained on respondent’s property for a prolonged period

of time and conducted a far-flung exploration of the front

yard. See ante, at 4 (“trawl for evidence with impunity”),

7 (“marching his bloodhound into the garden”). But that

is not what happened.

Detective Bartelt and Franky approached the front door

via the driveway and a paved path—the route that any

——————

1 See, e.g., Sloane, Dogs in War, Police Work and on Patrol, 46 J.

Crim. L., C. & P. S. 385 (1955–1956) (hereinafter Sloane).

2 M. Derr, A Dog’s History of America 68–92 (2004); K. Olsen, Daily

Life in 18th-Century England 32–33 (1999).

3 Sloane 388–389.

Cite as: 569 U. S. ____ (2013) 3

ALITO, J., dissenting

visitor would customarily use4—and Franky was on the

kind of leash that any dog owner might employ.5 As

Franky approached the door, he started to track an air-

borne odor. He held his head high and began “bracketing”

the area (pacing back and forth) in order to determine the

strongest source of the smell. App. 95–96. Detective

Bartelt knew “the minute [he] observed” this behavior that

Franky had detected drugs. Id., at 95. Upon locating the

odor’s strongest source, Franky sat at the base of the front

door, and at this point, Detective Bartelt and Franky im-

mediately returned to their patrol car. Id., at 98.

A critical fact that the Court omits is that, as respond-

ent’s counsel explained at oral argument, this entire

process—walking down the driveway and front path to the

front door, waiting for Franky to find the strongest source

of the odor, and walking back to the car—took approxi-

mately a minute or two. Tr. of Oral Arg. 57–58. Thus, the

amount of time that Franky and the detective remained

at the front porch was even less. The Court also fails to

mention that, while Detective Bartelt apparently did not

personally smell the odor of marijuana coming from the

house, another officer who subsequently stood on the front

porch, Detective Pedraja, did notice that smell and was

able to identify it. App. 81.

II

The Court concludes that the conduct in this case was a

search because Detective Bartelt exceeded the boundaries

of the license to approach the house that is recognized by

——————

4 See App. 94; App. to Brief for Respondent 1A (depiction of respond-

ent’s home).

5 The Court notes that Franky was on a 6-foot leash, but such a

leash is standard equipment for ordinary dog owners. See, e.g.,

J. Stregowski, Four Dog Leash Varieties, http://dogs.about.com/od/

toyssupplies/tp/Dog-Leashes.htm (all Internet materials as visited Mar.

21, 2013, and available in Clerk of Court’s case file).

4 FLORIDA v. JARDINES

ALITO, J., dissenting

the law of trespass, but the Court’s interpretation of the

scope of that license is unfounded.

A

It is said that members of the public may lawfully pro-

ceed along a walkway leading to the front door of a house

because custom grants them a license to do so. Breard v.

Alexandria, 341 U. S. 622, 626 (1951); Lakin v. Ames, 64

Mass. 198, 220 (1852); J. Bishop, Commentaries on the

Non-Contract Law §823, p. 378 (1889). This rule encom-

passes categories of visitors whom most homeowners

almost certainly wish to allow to approach their front

doors—friends, relatives, mail carriers, persons making

deliveries. But it also reaches categories of visitors who

are less universally welcome—“solicitors,” “hawkers,”

“peddlers,” and the like. The law might attempt to draw

fine lines between categories of welcome and unwelcome

visitors, distinguishing, for example, between tolerable

and intolerable door-to-door peddlers (Girl Scouts selling

cookies versus adults selling aluminum siding) or be-

tween police officers on agreeable and disagreeable mis-

sions (gathering information about a bothersome neighbor

versus asking potentially incriminating questions). But

the law of trespass has not attempted such a difficult

taxonomy. See Desnick v. American Broadcasting Cos., 44

F. 3d 1345, 1351 (CA7 1995) (“[C]onsent to an entry is

often given legal effect even though the entrant has inten-

tions that if known to the owner of the property would

cause him for perfectly understandable and generally

ethical or at least lawful reasons to revoke his consent”);

cf. Skinner v. Ogallala Public School Dist., 262 Neb. 387,

402, 631 N. W. 2d 510, 525 (2001) (“[I]n order to determine

if a business invitation is implied, the inquiry is not a

subjective assessment of why the visitor chose to visit the

premises in a particular instance”); Crown Cork & Seal

Co. v. Kane, 213 Md. 152, 159, 131 A. 2d 470, 473–474

Cite as: 569 U. S. ____ (2013) 5

ALITO, J., dissenting

(1957) (noting that “there are many cases in which an

invitation has been implied from circumstances, such as

custom,” and that this test is “objective in that it stresses

custom and the appearance of things” as opposed to “the

undisclosed intention of the visitor”).

Of course, this license has certain spatial and temporal

limits. A visitor must stick to the path that is typically

used to approach a front door, such as a paved walkway.

A visitor cannot traipse through the garden, meander into

the backyard, or take other circuitous detours that veer

from the pathway that a visitor would customarily use.

See, e.g., Robinson v. Virginia, 47 Va. App. 533, 549–550,

625 S. E. 2d 651, 659 (2006) (en banc); United States v.

Wells, 648 F. 3d 671, 679–680 (CA8 2011) (police exceeded

scope of their implied invitation when they bypassed the

front door and proceeded directly to the back yard); State

v. Harris, 919 S. W. 2d 619, 624 (Tenn. Crim. App. 1995)

(“Any substantial and unreasonable departure from an

area where the public is impliedly invited exceeds the

scope of the implied invitation . . . ” (internal quotation

marks and brackets omitted)); 1 W. LaFave, Search and

Seizure §2.3(c), p. 578 (2004) (hereinafter LaFave); id.,

§2.3(f), at 600–603 (“[W]hen the police come on to private

property to conduct an investigation or for some other

legitimate purpose and restrict their movements to places

visitors could be expected to go (e.g., walkways, drive-

ways, porches), observations made from such vantage points

are not covered by the Fourth Amendment” (footnotes

omitted)).

Nor, as a general matter, may a visitor come to the front

door in the middle of the night without an express invita-

tion. See State v. Cada, 129 Idaho 224, 233, 923 P. 2d 469,

478 (App. 1996) (“Furtive intrusion late at night or in the

predawn hours is not conduct that is expected from ordi-

nary visitors. Indeed, if observed by a resident of the

premises, it could be a cause for great alarm”).

6 FLORIDA v. JARDINES

ALITO, J., dissenting

Similarly, a visitor may not linger at the front door for

an extended period. See 9 So. 3d 1, 11 (Fla. App. 2008)

(case below) (Cope, J., concurring in part and dissenting in

part) (“[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”). The license is

limited to the amount of time it would customarily take to

approach the door, pause long enough to see if someone is

home, and (if not expressly invited to stay longer), leave.

As I understand the law of trespass and the scope of the

implied license, a visitor who adheres to these limitations

is not necessarily required to ring the doorbell, knock on

the door, or attempt to speak with an occupant. For ex-

ample, mail carriers, persons making deliveries, and in-

dividuals distributing flyers may leave the items they

are carrying and depart without making any attempt to

converse. A pedestrian or motorist looking for a particular

address may walk up to a front door in order to check a

house number that is hard to see from the sidewalk or

road. A neighbor who knows that the residents are away

may approach the door to retrieve an accumulation of

newspapers that might signal to a potential burglar that

the house is unoccupied.

As the majority acknowledges, this implied license to

approach the front door extends to the police. See ante, at

6. As we recognized in Kentucky v. King, 563 U. S. ___

(2011), police officers do not engage in a search when they

approach the front door of a residence and seek to engage

in what is termed a “knock and talk,” i.e., knocking on the

door and seeking to speak to an occupant for the purpose

of gathering evidence. See id., at ___ (slip op., at 16)

(“When law enforcement officers who are not armed with a

warrant knock on a door, they do no more than any pri-

vate citizen might do”). See also 1 LaFave §2.3(e), at 592

Cite as: 569 U. S. ____ (2013) 7

ALITO, J., dissenting

(“It is not objectionable for an officer to come upon that

part of the property which has been opened to public

common use” (internal quotation marks omitted)). Even

when the objective of a “knock and talk” is to obtain evi-

dence that will lead to the homeowner’s arrest and prose-

cution, the license to approach still applies. In other

words, gathering evidence—even damning evidence—is a

lawful activity that falls within the scope of the license to

approach. And when officers walk up to the front door of a

house, they are permitted to see, hear, and smell whatever

can be detected from a lawful vantage point. California v.

Ciraolo, 476 U. S. 207, 213 (1986) (“The Fourth Amend-

ment protection of the home has never been extended to

require law enforcement officers to shield their eyes when

passing by a home on public thoroughfares”); Cada, supra,

at 232, 923 P. 2d, at 477 (“[P]olice officers restricting their

activity to [areas to which the public is impliedly invited]

are permitted the same intrusion and the same level

of observation as would be expected from a reasonably

respectful citizen” (internal quotation marks omitted)); 1

LaFave §§2.2(a), 2.3(c), at 450–452, 572–577.

B

Detective Bartelt did not exceed the scope of the license

to approach respondent’s front door. He adhered to the

customary path; he did not approach in the middle of the

night; and he remained at the front door for only a very

short period (less than a minute or two).

The Court concludes that Detective Bartelt went too far

because he had the “objectiv[e] . . . purpose to conduct a

search.” Ante, at 8 (emphasis added). What this means, I

take it, is that anyone aware of what Detective Bartelt did

would infer that his subjective purpose was to gather

evidence. But if this is the Court’s point, then a standard

“knock and talk” and most other police visits would like-

wise constitute searches. With the exception of visits to

8 FLORIDA v. JARDINES

ALITO, J., dissenting

serve warrants or civil process, police almost always ap-

proach homes with a purpose of discovering information.

That is certainly the objective of a “knock and talk.” The

Court offers no meaningful way of distinguishing the

“objective purpose” of a “knock and talk” from the “objec-

tive purpose” of Detective Bartelt’s conduct here.

The Court contends that a “knock and talk” is different

because it involves talking, and “all are invited” to do that.

Ante, at 7–8, n. 4 (emphasis deleted). But a police officer

who approaches the front door of a house in accordance

with the limitations already discussed may gather evi-

dence by means other than talking. The officer may ob-

serve items in plain view and smell odors coming from the

house. Ciraolo, supra, at 213; Cada, 129 Idaho, at 232,

923 P. 2d, at 477; 1 LaFave §§2.2(a), 2.3(c), at 450–452,

572–577. So the Court’s “objective purpose” argument

cannot stand.

What the Court must fall back on, then, is the particular

instrument that Detective Bartelt used to detect the odor

of marijuana, namely, his dog. But in the entire body of

common-law decisions, the Court has not found a single

case holding that a visitor to the front door of a home

commits a trespass if the visitor is accompanied by a dog

on a leash. On the contrary, the common law allowed even

unleashed dogs to wander on private property without

committing a trespass. G. Williams, Liability for Animals

136–146 (1939); J. Ingham, A Treatise on Property in

Animals Wild and Domestic and the Rights and Respon-

sibilities Arising Therefrom 277–278 (1900). Cf. B.

Markesinis & S. Deakin, Tort Law 511 (4th ed. 1999).

The Court responds that “[i]t is not the dog that is the

problem, but the behavior that here involved use of the

dog.” Ante, at 7, n. 3. But where is the support in the law

of trespass for this proposition? Dogs’ keen sense of smell

has been used in law enforcement for centuries. The

antiquity of this practice is evidenced by a Scottish law

Cite as: 569 U. S. ____ (2013) 9

ALITO, J., dissenting

from 1318 that made it a crime to “disturb a tracking dog

or the men coming with it for pursuing thieves or seizing

malefactors.” K. Brown et al., The Records of the Parlia-

ments of Scotland to 1707, (St Andrews, 2007–2013),

online at http://www.rps.ac.uk/mss/1318/9. If bringing a

tracking dog to the front door of a home constituted a

trespass, one would expect at least one case to have arisen

during the past 800 years. But the Court has found none.

For these reasons, the real law of trespass provides no

support for the Court’s holding today. While the Court

claims that its reasoning has “ancient and durable

roots,” ante, at 4, its trespass rule is really a newly struck

counterfeit.

III

The concurring opinion attempts to provide an alterna-

tive ground for today’s decision, namely, that Detective

Bartelt’s conduct violated respondent’s reasonable expec-

tations of privacy. But we have already rejected a very

similar, if not identical argument, see Illinois v. Caballes,

543 U. S. 405, 409–410 (2005), and in any event I see no

basis for concluding that the occupants of a dwelling have

a reasonable expectation of privacy in odors that emanate

from the dwelling and reach spots where members of the

public may lawfully stand.

It is clear that the occupant of a house has no reasona-

ble expectation of privacy with respect to odors that can be

smelled by human beings who are standing in such places.

See United States v. Johns, 469 U. S. 478, 482 (1985)

(“After the officers came closer and detected the distinct

odor of marihuana, they had probable cause to believe

that the vehicles contained contraband”); United States

v. Ventresca, 380 U. S. 102, 111 (1965) (scent of ferment-

ing mash supported probable cause for warrant); United

States v. Johnston, 497 F. 2d 397, 398 (CA9 1974) (there

is no “reasonable expectation of privacy from drug agents

10 FLORIDA v. JARDINES

ALITO, J., dissenting

with inquisitive nostrils”). And I would not draw a line

between odors that can be smelled by humans and those

that are detectible only by dogs.

Consider the situation from the point of view of the

occupant of a building in which marijuana is grown or

methamphetamine is manufactured. Would such an oc-

cupant reason as follows? “I know that odors may ema-

nate from my building and that atmospheric conditions,

such as the force and direction of the wind, may affect the

strength of those odors when they reach a spot where

members of the public may lawfully stand. I also know

that some people have a much more acute sense of smell

than others,6 and I have no idea who might be standing in

one of the spots in question when the odors from my house

reach that location. In addition, I know that odors coming

from my building, when they reach these locations, may be

strong enough to be detected by a dog. But I am confident

that they will be so faint that they cannot be smelled by

any human being.” Such a finely tuned expectation would

be entirely unrealistic, and I see no evidence that society

is prepared to recognize it as reasonable.

In an attempt to show that respondent had a reasonable

expectation of privacy in the odor of marijuana wafting

from his house, the concurrence argues that this case is

just like Kyllo v. United States, 533 U. S. 27 (2001), which

held that police officers conducted a search when they

used a thermal imaging device to detect heat emanating

from a house. Ante, at 3–4 (opinion of KAGAN, J.). This

Court, however, has already rejected the argument that

——————

6 Some humans naturally have a much more acute sense of smell

than others, and humans can be trained to detect and distinguish odors

that could not be detected without such training. See E. Hancock, A

Primer on Smell, http://www.jhu.edu/jhumag/996web/smell.html. Some

individuals employed in the perfume and wine industries, for example,

have an amazingly acute sense of smell. Ibid.

Cite as: 569 U. S. ____ (2013) 11

ALITO, J., dissenting

the use of a drug-sniffing dog is the same as the use of a

thermal imaging device. See Caballes, 543 U. S., at 409–

410. The very argument now advanced by the concurrence

appears in Justice Souter’s Caballes dissent. See id., at

413, and n. 3. But the Court was not persuaded.

Contrary to the interpretation propounded by the con-

currence, Kyllo is best understood as a decision about the

use of new technology. The Kyllo Court focused on the fact

that the thermal imaging device was a form of “sense-

enhancing technology” that was “not in general public

use,” and it expressed concern that citizens would be “at

the mercy of advancing technology” if its use was not

restricted. 533 U. S., at 34–35. A dog, however, is not a

new form of “technology or a “device.” And, as noted, the

use of dogs’ acute sense of smell in law enforcement dates

back many centuries.

The concurrence suggests that a Kyllo-based decision

would be “much like” the actual decision of the Court, but

that is simply not so. The holding of the Court is based on

what the Court sees as a “ ‘physical intrusion of a constitu-

tionally protected area.’ ” Ante, at 3 (quoting United States

v. Knotts, 460 U. S. 276, 286 (1983) (Brennan, J., concur-

ring in judgment)). As a result, it does not apply when a

dog alerts while on a public sidewalk or street or in the

corridor of a building to which the dog and handler have

been lawfully admitted.

The concurrence’s Kyllo-based approach would have a

much wider reach. When the police used the thermal

imaging device in Kyllo, they were on a public street, 533

U. S., at 29, and “committed no trespass.” Ante, at 3.

Therefore, if a dog’s nose is just like a thermal imaging

device for Fourth Amendment purposes, a search would

occur if a dog alerted while on a public sidewalk or in the

corridor of an apartment building. And the same would be

true if the dog was trained to sniff, not for marijuana, but

for more dangerous quarry, such as explosives or for a

12 FLORIDA v. JARDINES

ALITO, J., dissenting

violent fugitive or kidnaped child. I see no ground for

hampering legitimate law enforcement in this way.

IV

The conduct of the police officer in this case did not

constitute a trespass and did not violate respondent’s

reasonable expectations of privacy. I would hold that this

conduct was not a search, and I therefore respectfully

dissent.

This is a copy of a public record, reproduced as it was published. It is not legal advice, and it may not be the version a court would rely on. Check the official source before you cite it.

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