Amicus Curiae Brief — Eric Tyrell Johnson, Petitioner v. United States

No. 25-774

In the Supreme Court of the United States

ERIC TYRELL JOHNSON, PETITIONER,

v.

UNITED STATES

ON PETITION FOR A WRIT OF CERTIORARI

TO THE UNITED STATES COURT OF APPEALS

FOR THE FOURTH CIRCUIT

BRIEF OF AMICUS CURIAE

PROFESSOR LAURENT SACHAROFF

SUPPORTING PETITIONER

NICOLE L. MASIELLO

Counsel of Record

ARNOLD & PORTER

KAYE SCHOLER LLP

250 West 55th Street

New York, NY 10019

(212) 836-8000

nicole.masiello@arnoldporter.com

R. STANTON JONES

ARNOLD & PORTER

KAYE SCHOLER LLP

601 Massachusetts Ave., NW

Washington, DC 20001

(202) 942-5000

TABLE OF CONTENTS

Page

Interests of Amicus Curiae ................................................ 1

Summary of Argument ........................................................ 1

Argument .............................................................................. 4

I. An apartment resident enjoys a legitimate

expectation of privacy against the disclosure of

any facts about the home. ............................................ 4

A. The Kyllo line of cases correctly rejects

assessing the quality of facts learned about

the home. ................................................................. 4

B. Caballes misconstrued Kyllo and wrongly

assessed the quality of individual facts about

the interior of a place. ............................................ 8

C. The Court need not overrule Caballes to find

apartments are protected. ................................... 10

II. Even under a fact-based approach, A person

has a legitimate expectation of privacy in

avoiding a drug-sniffing dog alert. ............................ 13

A. A false alert invades a legitimate expectation

of privacy. .............................................................. 13

B. A person has a legitimate expectation of

privacy in the unknowing possession of

contraband. ............................................................ 16

Conclusion ........................................................................... 20

(i)

TABLE OF AUTHORITIES

Cases

Page(s)

Arizona v. Hicks,

480 U.S. 321 (1987) ........................................................ 4, 7

Bagwell v. Peninsula Reg’l Med. Ctr.,

665 A.2d 297 (Md. Ct. Spec. App. 1995) ........................ 14

Entick v. Carrington,

19 How. St. Tr. 1029 (1765) ............................................ 10

Florida v. Jardines,

569 U.S. 1 (2013) ........................................................ 12, 15

Illinois v. Caballes,

543 U.S. 405 (2005) .............................. 2, 8, 9, 11-13, 16-18

Jardines v. State,

73 So. 3d 34 (Fla. 2011) ................................................... 15

Kyllo v. United States,

533 U.S. 27 (2001) .............................................. 2, 4, 5, 6, 9

Miller v. United States,

357 U.S. 301 (1958) .......................................................... 10

Payton v. New York,

445 U.S. 573 (1980) .................................................. 4, 6, 10

Rakas v. Illinois,

439 U.S. 128 (1978) .......................................................... 17

Semayne's Case,

77 Eng. Rep. 194 (K.B. 1603) ..................................... 4, 10

Silverman v. United States,

365 U.S. 505 (1961) ............................................................ 4

Staples v. United States,

511 U.S. 600 (1994) .......................................................... 18

United States v. Jacobsen,

466 U.S. 109 (1984) .............................................. 10, 11, 17

United States v. Karo,

468 U.S. 705 (1984) .................................................... 4, 7, 8

(ii)

iii

Cases—Continued

Page(s)

United States v. Place,

462 U.S. 696 (1983) ................................................ 2, 10, 11

United States v. Scott,

610 F.3d 1009 (8th Cir. 2010) ........................................... 2

United States v. Whitaker,

820 F.3d 849 (7th Cir. 2016) ............................................. 1

Statutes

Md. Code Ann., Crim. Law § 6-202(a) ............................. 18

Other Authorities

Arnold H. Loewy, The Fourth Amendment

as a Device for Protecting the Innocent,

81 Mich. L. Rev. 1229 (1983) .......................................... 17

Edward J. Bloustein, Privacy as an Aspect

of Human Dignity: An Answer to Dean

Prosser, 39 N.Y.U. L. Rev. 962 (1964) .......................... 15

Eyder Peralta, Report: Drug Sniffing

Dogs are Wrong More Often than Right,

NPR (Jan. 7, 2011, at 13:27 ET),

https://perma.cc/8U9K-ZDPQ ....................................... 13

Hansard, Parliamentary History of

England (1813), Vol. 15, column 1307 ........................... 10

Laurent Sacharoff, The Binary Search

Doctrine, 42 Hofstra L. Rev. 1139 (2014) ................... 2, 9

Morgan Smith, Beware of the Drug

Detection Dog: The Fourth Amendment,

Drug Detection Dogs, and State

Legalization of Marijuana, 73 SMU L.

Rev. 611 (2020) ................................................................. 19

Restatement (Second) of Torts § 652A ............................ 14

Restatement (Second) of Torts § 652E ............................ 14

Restatement (Second) of Torts § 163 .............................. 10

iv

Other Authorities—Continued

Page(s)

Restatement (Second) of Torts § 571 .............................. 14

Richard E. Myers II, Detector Dogs and

Probable Cause, 14 Geo. Mason L. Rev.

1, 4–5 (2006)...................................................................... 18

William L. Prosser, Privacy, 48 Cal. L.

Rev. 383, 399 (1960) ......................................................... 14

INTERESTS OF AMICUS CURIAE1

Amicus curiae Laurent Sacharoff is a law professor

at University of Denver Sturm College of Law. He has

written numerous articles on criminal procedure and, in

particular, on dog sniffs and the Fourth Amendment. As

a scholar in the field of Fourth Amendment law, he has an

interest in the correct interpretation of the Fourth

Amendment and the protection of individual liberty in the

face of potentially intrusive government surveillance.

Based on his scholarly knowledge on the Fourth

Amendment, amicus submits this brief to urge the Court

to grant certiorari and reverse the judgment of the

Fourth Circuit.

SUMMARY OF ARGUMENT

This case concerns whether a dog sniff of an

apartment for drugs is a Fourth Amendment search. This

brief considers the question presented under the

reasonable expectation of privacy test. Under this test,

courts have split over whether such a dog sniff constitutes

a search because they follow one of two radically different

conceptions of how the Fourth Amendment applies to the

home—a place-based approach versus a fact-based

approach. This Court should grant the petition to resolve

this conflict in favor of a place-based approach,

recognizing dog sniffs of any home as a search.

The reason for the court split is clear. Those courts

finding a dog sniff of an apartment to be a search treat the

home as a place entitled to seclusion from government

surveillance regardless of the nature of the facts revealed.

See, e.g., United States v. Whitaker, 820 F.3d 849, 853 (7th

No counsel for a party authored this brief in whole or in part. No

person other than amicus or his counsel made a monetary

contribution to its preparation or submission. The parties were

given timely notice of amicus’s intent to file this brief.

1

(1)

2

Cir. 2016). These courts follow the conception of the home

articulated in Kyllo v. United States, which said that

courts should not measure the “quality or quantity” of any

facts potentially disclosed. 533 U.S. 27, 37 (2001). Even if

surveillance reveals only a single trivial or nonintimate

fact, such as the presence of a “rug on the vestibule floor,”

discovering this fact counts as a Fourth Amendment

search. As a result, when a dog alerts to the putative

presence of drugs in an apartment, this alert constitutes a

search even if the possession of contraband is not a

legitimately private or intimate fact considered in

isolation. That fact becomes an intimate fact, it is deemed

intimate, because it is a disclosure about the interior of the

home; it is a private fact. Id.; see also Laurent Sacharoff,

The Binary Search Doctrine, 42 Hofstra L. Rev. 1139

(2014).

On the other hand, those courts finding no search

essentially atomize a home’s privacy into discrete facts,

weigh those individual facts, and determine whether they

are worthy of privacy protection. See, e.g., United States

v. Scott, 610 F.3d 1009, 1016 (8th Cir. 2010). These courts

follow Illinois v. Caballes, 543 U.S. 405 (2005), and United

States v. Place, 462 U.S. 696 (1983), even though those

cases concerned cars and luggage and not homes. In

particular, these lower courts apply the mechanical test

that a dog sniff that reveals nothing but the presence or

absence of contraband does not count as a search. This

binary-search test measures the quality of the particular

fact (apparent drug possession) to assess its degree of

privacy—an approach flatly rejected by Kyllo for homes.

Even though lower courts err in applying Caballes to the

home, this Court need not overrule Caballes to reach the

correct result for homes.

The petition should also be granted because, even if

one were to accept Caballes’s fact-based approach, a

homeowner still enjoys a legitimate expectation of privacy

3

in the supposed fact that she possesses drugs as indicated

by any dog alert. Caballes and Place were wrong to hold

that a person enjoys no legitimate expectation of privacy

in this fact, and the principle announced in those cases for

cars and luggage should not be extended to homes. A

person enjoys a legitimate expectation of privacy whether

the alert is true or false.

First, if the alert is false—which can happen in up to

50 percent of alerts, according to some studies—the

homeowner has essentially been falsely accused of a

crime. Such a false accusation does effect a privacy

invasion, as seen most readily from the privacy tort of

false light. This tort expressly protects against the

generation and dissemination of false and negative

information as a privacy invasion. Even if some elements

are not met, the tort shows conceptually that a person has

a legitimate expectation of privacy against being

associated with negative false facts, such as a false alert

for drugs. The tort of defamation supports the same

principle.

Second, if the alert is true, then there are drugs in the

home. Caballes largely envisioned such accurate alerts,

albeit for cars. But that Court also assumed that those

motorists knowingly possessed drugs, that they were

essentially drug dealers or traffickers, and that their

criminal guilt eviscerated the legitimacy of any privacy

interest. But when a dog accurately alerts to the presence

of drugs in a home, the homeowner or resident may be

unaware of their presence and therefore not guilty of a

crime. Dogs alert to drug residue, which can be found in

up to 80 percent of currency; residue can contaminate

clothes and furniture as well. Guests or previous tenants

may have left small amounts of drugs behind. Is a

homeowner to frisk all guests and conduct regular sweeps

of his apartment for drugs or drug residue? Rather, a

home’s privacy and security under the Fourth

4

Amendment should afford him freedom and “repose”

from such measures. See Payton v. New York, 445 U.S.

573, 597 n.44 (1980) (“‘[T]he house of every one is to him

as his castle and fortress, as well for his defence against

injury and violence, as for his repose.’”) (quoting

Semayne’s Case, 77 Eng. Rep. 194, 195 (K.B. 1603)).

ARGUMENT

I.

AN APARTMENT RESIDENT ENJOYS A LEGITIMATE

EXPECTATION OF PRIVACY AGAINST THE

DISCLOSURE OF ANY FACTS ABOUT THE HOME.

Courts considering dog sniffs of apartments should

follow the place-based reasoning of Kyllo rather than the

fact-based reasoning of Caballes and Place. This Court

should therefore resolve the split among the circuit and

state courts in favor of a Kyllo-type approach. Such an

approach would not require overruling Caballes.

A.

The Kyllo line of cases correctly rejects assessing

the quality of facts learned about the home.

Kyllo v. United States, 533 U.S. 27 (2001), and its

predecessors treat the home as a place rather than as a

collection of facts when considering a resident’s

reasonable expectation of privacy under the Fourth

Amendment; they therefore reject disaggregating and

assessing any individual facts that might be learned about

the home’s interior. See Kyllo, 533 U.S. at 37; Arizona v.

Hicks, 480 U.S. 321, 325 (1987); United States v. Karo, 468

U.S. 705, 714–717 (1984); Payton v. New York, 445 U.S.

573, 589 (1980). Even trivial facts that are neither private

nor intimate are protected because they concern the

interior of the home. Kyllo, 533 U.S. at 37–38; cf.

Silverman v. United States, 365 U.S. 505, 509 (1961)

(holding that the Fourth Amendment protects against

even trivial physical intrusions into the home).

Thus, this Court’s declarations that the home is “first

among equals” and enjoys “heightened privacy,” reflect

5

not only a higher degree of privacy, or a greater weight in

the balance, but a different type of privacy—one that

treats an intrusion as per se injurious even if no harm in

fact occurs and if the facts revealed are not intimate. The

Fourth Amendment draws a “bright line” at the home to

protect the privacy, security and repose of the homeowner

or resident.

Kyllo makes the case most expressly. Both the

holding and reasoning of Kyllo show that this Court found

a Fourth Amendment search based entirely upon the

nature of the place surveilled and not at all upon the

nature of the facts either disclosed or potentially

disclosed. As this Court said without equivocation: “The

Fourth Amendment’s protection of the home has never

been tied to measurement of the quality or quantity of

information obtained.” 533 U.S. at 37.

In particular, in Kyllo, law enforcement used thermal

imaging to measure the heat on the outside of a triplex

home to infer the presence of grow lights and marijuana

within. This Court held this was a search because the

agents 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.” Id. at 40.

Even when we consider the words of the holding alone, we

see it ignores the nature or quality of the facts learned;

rather, it protects any facts relevant to the interior of the

home.

This Court’s reasoning furthered the point when it

responded to the government’s argument that this Court

should assess the quality or nature of particular facts. In

assessing whether remote detecting tools effect a search,

the government argued, courts should distinguish based

on the level of intimacy of the facts revealed. Id. at 37. This

Court rejected that approach repeatedly and in depth.

The Fourth Amendment protects the home

categorically as a place, this Court reasoned, and it is

6

therefore misguided to attempt to distinguish intimate

from non-intimate facts and protect the former only. As to

place, it noted that “the entire area” of the home “is held

safe from prying government eyes.” Id. After all, “the

Fourth Amendment draws ‘a firm line at the entrance to

the house.’” Id. at 40 (quoting Payton, 445 U.S. at 590).

Kyllo focused even more precisely on assessing facts

individually and expressly rejected the government’s

proposed approach: “The Fourth Amendment's

protection of the home has never been tied to

measurement of the quality or quantity of information

obtained.” 533 U.S. at 37. Rather, it said that all facts

inside the home are intimate in the figurative sense: All

facts, even those that are not intimate, are deemed

intimate because they are in the home—a categorically

protected place. Id. (“In the home, our cases show, all

details are intimate details, because the entire area is held

safe from prying government eyes.”). Referring to earlier

cases that involved facts that were not intimate or private

in and of themselves, the Court wrote: “These were

intimate details because they were details of the home.”

Id. at 38. Deeming facts of the home intimate means they

are private.

The Court highlighted this crucial point with a few

examples. Most famously, it noted that perhaps a thermal

imager could discern at “what hour each night the lady of

the house takes her daily sauna and bath” or “that

someone left a closet light on.” Id. This Court recognized

the first as an example of an intimate fact, the second, a

nonintimate fact, in order to show that it did not matter.

All facts about the inside of the home are protected,

whether intimate or not intimate. The Fourth

Amendment protects even details about “the nonintimate

rug on the vestibule floor.” Id. at 37.

Similarly, in Arizona v. Hicks, a police officer lawfully

inside the respondent’s home—but lacking a search

7

warrant—read and recorded the serial number of a

turntable he suspected was stolen. 480 U.S. 321, 323–24

(1987). The turntable had indeed been stolen and the

respondent was subsequently indicted for robbery. Id.

The question before this Court was whether the officer

conducted a search when he lifted the turntable to look

underneath. Id. The place in question, therefore, was the

bottom of the turntable—found in a home. This Court

could have taken a fact-based approach and said that the

serial number underneath the turntable was a private fact

that the police learned, and, therefore, Hicks’s privacy

was intruded upon; or it could have said that the serial

number was an insignificant fact, and, therefore, that the

police did not invade Hicks’s privacy. But it did not take

this fact-based approach.

Instead, this Court focused on the place, famously,

writing that upending the turntable would have been a

search even if there had been no serial number at all. “A

search is a search, even if it happens to disclose nothing

but the bottom of a turntable.” Id. at 325. In so holding, it

rejected the view of the dissenting Justices that a

“cursory inspection” for mundane facts such as a serial

number or brand name on the surface should not

constitute a Fourth Amendment search as would a “fullblown” search of the home. Id. at 333. The majority

insisted that it is the place that confers a reasonable

expectation of privacy, irrespective of any facts, intimate

or not, that might be learned.

Other cases similarly treat the home as a place to be

protected without considering the quality of any

individual facts learned. In United States v. Karo, law

enforcement agents used a beeper to trace a can of ether,

used as part of the drug trade, into the respondent’s

home. 468 U.S. 705, 708–11 (1984). The government

argued that this surveillance was not a search because

“the beeper constitute[d] only a minuscule intrusion on

8

protected privacy interests.” Id. at 717. This Court

rejected the argument. While it recognized that the

presence of the can of ether was critical in securing a

search warrant for the home, it did not weigh how

intimate or legitimate the fact itself was. Id. at 714–15.

Rather, this Court treated the home as per se protected

against the disclosure of any facts. Id. at 717. The

surveillance was therefore a Fourth Amendment search,

even though the ether was so closely tied to criminal

activity. In a telling conclusion that also challenges the

approach in Caballes, this Court in Karo said: “Those

suspected of drug offenses are no less entitled to that

protection than those suspected of nondrug offenses.” Id.

B. Caballes misconstrued Kyllo and wrongly

assessed the quality of individual facts about the

interior of a place.

Illinois v. Caballes misunderstood Kyllo as

approving an assessment of the nature or quality of the

facts that are or could be learned. 543 U.S. 405, 409–10

(2005). Kyllo held exactly the opposite. While Caballes

was distinguishing between so-called lawful and unlawful

facts, rather than between intimate and non-intimate

facts, this Court in Kyllo had drawn no such distinction.

Specifically, Caballes claimed that “critical” to the Kyllo

decision was that the thermal imager could detect lawful

activity. 543 U.S. at 409–10. But Kyllo said no such thing

and did not even use the word “lawful” in connection with

activities in the home. What was critical to the Kyllo

decision, as detailed above, was that the place was a home,

and all facts emanating from it were protected.

Caballes similarly misconstrued Kyllo’s whimsical

example of the sauna. It wrote that the Kyllo court had

written that the thermal imager could detect sauna use,

that such sauna use was an “intimate fact” about the

home, and that these factors were also “critical” to the

Kyllo decision. Caballes, 543 U.S. at 409–10 (“Critical to

9

that decision was the fact that the device was capable of

detecting lawful activity—in that case, intimate details in

a home, such as ‘at what hour each night the lady of the

house takes her daily sauna and bath.’”). Caballes pointed

to these observations to conclude that Kyllo approved of

courts assessing the quality of facts as intimate or not,

lawful or unlawful, and that, in Caballes, the Court was

therefore justified in distinguishing among the quality of

facts observed. Id. at 409–10.

But Kyllo made up the sauna example, as well as the

example of the closet light and the foyer rug. Kyllo, 533

U.S. at 37–38. The thermal imager in Kyllo did not

disclose any sauna information, there was no suggestion

the thermal imager there could have discerned when any

putative sauna was running, and, more generally, home

saunas are very well insulated. Id. at 50 (Stevens, J.,

dissenting) (noting that the imager there did not, and

could not, have detected the lady in her sauna or the foyer

rug). Indeed, the majority expressly restated the lower

court finding that “‘[n]o intimate details of the home were

observed.’” Id. at 30; see also Sacharoff, 42 HOFSTRA L.

REV. at 1155–56 (examining the sauna example).

Even aside from these errors, this Court in Caballes

and Place erred conceptually by treating car trunks and

luggage not as places entitled to privacy protection, but as

yielders of facts to be atomized and assessed for their

nature and quality. Whether the analysis assesses based

on intimacy or so-called lawfulness, i.e., the possession of

contraband, the approach contradicts the predominant

historical principle that the Fourth Amendment protects

the private place and not the facts about that place—at

least and especially for the home. To be secure in one’s

home means not having to worry about exposing any fact

from within.

Thus, when William Pitt described the heroic cottage

standing against the depredations of the Crown, he

10

emphasized its dignity against intrusion and not that it

might guard particularity valuable information. Miller v.

United States, 357 U.S. 301, 307 (1958) (“‘The poorest man

may in his cottage bid defiance to all the forces of the

Crown.’”) (quoting Hansard, Parliamentary History of

England (1813), vol. 15, column 1307). Edward Coke, in

calling a home one’s “castle and fortress” for his “repose,”

focused too on security and dignity, since castles are

known more for majesty, power, and security than as a

place for guarding intimate details. Payton, 445 U.S. at

597 n.44 (quoting Semayne’s Case, 77 Eng. Rep. at 195).

True, Pitt and Coke had in mind physical intrusions,

but the principle that the home protects repose and

security categorically applies equally to remote

surveillance. Indeed, the analogy of such surveillance to

the tort of civil trespass furthers the idea that a search

cannot turn on the nature or quality of the fact learned or

the degree of intrusion. After all, the tort of trespass to

land required then and requires today no showing of harm

or damage—the physical intrusion into another’s land is

the injury. Restatement (Second) of Torts § 163; see also

Entick v. Carrington, 19 How. St. Tr. 1029, 1066 (1765)

(holding that a person is liable for trespass even “though

the damage” of their actions “be nothing”).

C.

The Court need not overrule Caballes to find

apartments are protected.

Even though amicus disagrees with the premises

upon which the Court rested when deciding Illinois v.

Caballes, the Court here need not overrule it to afford

apartment dwellers protection against dog sniffs. This

Court could find that such residents enjoy a reasonable

and legitimate expectation of privacy consistent with the

approach taken both there and in the entire line of related

cases. United States v. Jacobsen, 466 U.S. 109 (1984);

Place, 462 U.S. 695. In these cases, the Court was careful

to avoid ruling out any expectation of privacy and instead

11

employed balancing tests, applied to the specific facts in

those cases, indicating the factual scenarios were special.

For example, in Place, the Court pointed out that the

luggage sniffed there was in public. The Court appeared

to concede that there was some intrusion, albeit one that

was “much less” than a “typical search.” 462 U.S. at 707.

It limited its holding to “the particular course of

investigation that the agents intended to pursue here.” Id.

Jacobsen similarly noted that it addressed very

special facts: The “official conduct of the kind disclosed in

the record.” 466 U.S. at 124. The Court noted that such

chemical tests for drugs were special for two reasons:

(1) The police already lawfully had the substance in their

possession, and (2) such tests were almost always positive.

Id. at 123 (“It is probably safe to assume that virtually all

of the tests conducted under circumstances comparable to

those disclosed by this record would result in a positive

finding”).

Caballes also limited the scope of its holding to a dog’s

sniff of a car during a lawful traffic stop. It even limited

this holding by adding the term “generally”; in the Court’s

reasoning, such dog sniffs during lawful traffic stops

“generally” do not “implicate legitimate privacy

interests” and therefore are not searches. 543 U.S. at 409.

We can contrast this limited holding—even with respect

to cars—with what the Court did not hold: The Court did

not, for example, hold more broadly that dog sniffs of cars,

wherever they may be found, including for example every

car in a parking lot, are not searches. Nor did it assert

motorists have no expectation of privacy; it merely held

that during a lawful traffic stop, any such interest does not

rise to a constitutional level. Id. at 410. This is a balancing

test.

The Caballes line of cases should have little influence

on homes. This Court could hold that a resident enjoys a

legitimate expectation of privacy in the home, as against

12

dog sniffs, consistent with Caballes line of cases. The

balance reverses for homes. Residents have far higher

expectations of privacy in their homes, including

apartments. Homes are not luggage in highly public

airports where they are already vulnerable to inspection.

Homes are not powder already exposed and therefore

involving no searched place at all.

But most important, and considering Caballes itself,

homes are not cars. Caballes emphasized that the rules for

cars will often not apply to homes because cars enjoy a

lower expectation of privacy than homes. Id. at 409–10.

Cars are highly regulated and mobile; homes are not and,

in fact, have been dubbed “first among equals” when it

comes to the Fourth Amendment. Florida v. Jardines,

569 U.S. 1, 6 (2013).

These principles may have guided the Court in

Jardines to conclude that it need not worry about

overruling Caballes. Jardines considered the dog sniff of

a house under a physical trespass test for search. In doing

so, it noted that it need not consider the reasonable

expectation of privacy test. 569 U.S. at 11. Avoiding such

a test strongly signals that the Court did not believe that

Caballes mandated a result with respect to homes, one

way or the other. Indeed, even though Jardines relied on

physical trespass, much of its language relies on the

privacy a person enjoys in her home. After all, police

entering a porch without a dog perform no search; those

with a drug sniffing dog do, according to this Court. The

only difference between this hypothetical and Jardines is

the sniff, and the sniff only makes a difference because its

function is to learn private details about the inside of the

home.

13

II.

EVEN UNDER A FACT-BASED APPROACH, A PERSON

HAS A LEGITIMATE EXPECTATION OF PRIVACY IN

AVOIDING A DRUG-SNIFFING DOG ALERT.

This Court should grant certiorari for a second

reason: Even if we take the fact-based approach of

Caballes, the fact of a dog alert does give rise to a

reasonable and legitimate expectation of privacy,

especially in the home. We will first consider false alerts,

then true alerts.

A.

A false alert invades a legitimate expectation of

privacy.

If the dog alert is false, there are no drugs in the

home. Studies vary widely, but at least some show that

dogs falsely alert at or above 50 percent of the time. See

Eyder Peralta, Report: Drug Sniffing Dogs are Wrong

More Often than Right, NPR (Jan. 7, 2011, at 13:27 ET),

https://perma.cc/8U9K-ZDPQ (According to one analysis,

“officers found drugs or paraphernalia in only 44 percent

of cases in which the dogs had alerted them”). But even

false alerts at a far lower rate, such as 10 percent, would

implicate 10 percent of those subjected to such

surveillance, and, of course, police cannot know in advance

which alerts are false.

Caballes addressed the question of false alerts

dismissively, in a single sentence without any analysis. It

said, essentially, that a false alert does not invade person’s

legitimate expectation of privacy. Caballes, 543 U.S. at

409 (noting that the respondent had “not suggest[ed] that

an erroneous alert, in and of itself, reveals any legitimate

private information”). And, of course, the Caballes test

logically presupposes as much. This Court appeared to

believe that the generation of false facts about a person

cannot invade their privacy because those facts are false.

That view is wrong. False facts about a person can, of

course, contribute to an invasion of privacy, both legally

and as a matter of common sense.

14

First, consider the law. The tort of false light, a

privacy tort, recognizes that false facts are an element of

an invasion of privacy. Restatement (Second) of Torts

§§ 652A, 652E. “Essential” to the tort is that the facts are

“not true.” Id. § 652E cmt. a. And of course, this tort is an

invasion of privacy; as the Restatement says, placing

another “in a false light before the public” makes one

liable for “invad[ing] the right of privacy of another.” Id.

§ 652A; see also id. § 652E cmt. b (describing false light as

an “invasion of privacy” because it presents a person to

the public “otherwise than as he is”). False light is a tort

recognized, and specifically recognized as a “privacy”

right, in many states, including Maryland where

petitioner lived and was arrested. See, e.g., Bagwell v.

Peninsula Reg’l Med. Ctr., 665 A.2d 297, 318 (Md. Ct.

Spec. App. 1995) (using the definition of the Second

Restatement). Defamation overlaps significantly with the

tort of false light; defamation also shows that a person

enjoys a legitimate interest in avoiding false negative

facts about them.

Not surprisingly, under a false light analysis,

accusing someone of a crime they have not committed

would be the type of falsity that could support the tort of

false light. William L. Prosser, Privacy, 48 Cal. L. Rev.

383, 399 (1960) (giving as an example of the tort of false

light the act of including a person never convicted of a

crime in a “‘rogues-gallery’ of convicted criminals”).

Slander law treats false accusations of certain crimes as

slander per se, without any need to show special, i.e.,

concrete, harm. Restatement (Second) of Torts § 571.

The point is not that the elements of these torts are

met, nor that a suspect has a cause of action against the

officers. After all, officers would likely believe any false

alert to be true. The point is that Caballes was wrong to

say false facts do not implicate a legitimate expectation of

privacy.

15

Second, common sense tells us that a false dog alert

implicates legitimate interests. A false alert announces to

the officers false and highly negative information about

the homeowner—namely, that they possess illegal drugs.

It also may, at the same time, announce the same negative

facts to attendant media, neighbors, and even family

members. See, e.g., Jardines v. State, 73 So. 3d 34, 46-49

(Fla. 2011) (noting that “[c]ontrary to popular belief, a

‘sniff test’ conducted at a private residence is not

necessarily a casual affair”), aff’d on other grounds sub

nom. Florida v. Jardines, 569 U.S. 1 (2013). Finally,

officers will also take this false information to court to

obtain a warrant, alleging in court and court documents

this same false information. Putting aside any later

search, this false portrayal of the individual in court

undermines their privacy interests and its inextricably

tied to the dog sniff and alert.

This false information invades the person’s privacy

because it intrudes upon an individual’s personhood and

dignity, their place and role in the world. See, e.g., Edward

J. Bloustein, Privacy as an Aspect of Human Dignity: An

Answer to Dean Prosser, 39 N.Y.U. L. Rev. 962, 991

(1964). Individuals encounter this all the time. Even

something as simple as leaving a store or a library and

setting of an alarm (falsely) makes one feel shame that

intrudes upon one’s sense of privacy and security—even

if the intrusion does not amount to a legal cause of action.

Of course, the police sometimes generate false and

negative information about a person as part of a

legitimate investigation without doing anything wrong or

violating the Fourth Amendment. Simply generating such

information alone does not implicate the Fourth

Amendment. But when the false information comes from

the interior of the home, as a result of government

surveillance, the Fourth Amendment comes into play.

16

It is critical to note that this argument is different

from an argument that a false alert will lead to a later fullblown search of the home, and that this later search

invades an expectation of privacy. While Justice Souter

argued courts should take that later search into account,

Caballes, 543 U.S. at 413 (Souter, J., dissenting), the

argument here merely contends that a person has an

interest in avoiding false negative information about her

in the form of the alert. Relatedly, this Court in Caballes

said false alerts were too rare to undermine its argument,

but again, that argument largely related to any later

warranted search and whether there would be probable

cause for that later search. False alerts may be rare

enough so as not to undermine probable cause for a

subsequent search and yet common enough to afford the

homeowner a legitimate interest in avoiding the dog sniff

that leads to any false alert.

B. A person has a legitimate expectation of privacy

in the unknowing possession of contraband.

Even if a dog alert accurately reveals the presence of

drugs in the home, a person enjoys a legitimate

expectation of privacy in this fact if she does not know

about the drugs—an occurrence common enough to

undermine Caballes. Dogs cannot smell mens rea.

To restate, Caballes held that a dog sniff does not

constitute a search because it reveals the presence or

absence of contraband only, and, critically here, a person

has no legitimate expectation of privacy in the fact that

they possess contraband. See Caballes, 543 U.S. at 408

(noting that “governmental conduct that only reveals the

possession of contraband ‘compromises no legitimate

privacy interest’”).

But the key rationale for this conclusion arose from

the Court’s further premise: The person at issue

knowingly possesses. The Court’s notion that drug

possession deserves no privacy, that a person has no

17

interest in keeping “secret” such a fact, rested upon its

criminality—and incorrectly assumed all who possess

knowingly possess.

This Court in United States v. Jacobsen made this

presumption of criminality express. 466 U.S. 109 (1984).

It pointed out that Congress had made cocaine possession

criminal and thus treated “the interest in ‘privately’

possessing cocaine as illegitimate.” Id. at 123. It expressly

spoke of criminals when it pointed to burglars as lacking

privacy interests: “A burglar plying his trade in a summer

cabin during the off season” has no privacy expectation

“which the law recognizes as ‘legitimate.’” Id. at 122 n.22

(quoting Rakas v. Illinois, 439 U.S. 128, 143–44 n.12

(1978)). It denominated his activity as “wrongful.” It also

cited a law review article that expressly argued that the

Fourth Amendment, in principle, protects only those

“innocent” of the crime investigated and that those who

are guilty are protected only in order to further protection

of the “innocent.” Id. at 123 n.23 (citing Arnold H. Loewy,

The Fourth Amendment as a Device for Protecting the

Innocent, 81 Mich. L. Rev. 1229 (1983)).

Caballes relied upon Jacobsen and its rationale: That

one guilty of a crime has no right to keep that fact secret.

But Caballes also independently made clear that it

presumed the person knowingly possesses. It made this

clear when it distinguished Kyllo. The thermal imager in

Kyllo could capture lawful activity as well as unlawful,

Caballes asserted. Caballes, 543 U.S. at 409 (“Critical to

[the Kyllo] decision was the fact that the device was

capable of detecting lawful activity.”). Detecting lawful

activity does invade a reasonable expectation of privacy,

the Caballes court continued. The dog sniff, by contrast,

can detect unlawful activity only and therefore intrudes

upon no legitimate expectation of privacy. The criminality

and unlawfulness of the possession, and the fact of that

18

possession, are therefore critical to the Caballes decision.

But again, possession is only unlawful if it is knowing.

After all, what does it mean to be guilty of drug

possession, to be a burglar, to do something that is

“wrongful” and “unlawful?” It means, of course, to have

mens rea, to possess knowingly. A plumber inside a

summer cabin, turning off the water for the winter, is not

a burglar because he has no intent to steal. See, e.g., Md.

Code Ann., Crim. Law § 6-202(a) (“A person may not

break and enter the dwelling of another with the intent to

commit theft.”). That means that a homeowner, or

motorist, who possesses cocaine without knowledge—if

“possess” is even the right word—commits no crime, does

nothing “wrongful,” and does nothing that is “unlawful.”

Mens rea is no mere technicality; it is critical to the

wrongfulness and the unlawfulness of nearly all crimes

including drug crimes. See Staples v. United States, 511

U.S. 600, 605 (1994) (noting that “the requirement of some

mens rea for a crime is firmly embedded” in common law).

And, of course, people commonly possess drugs

without the knowledge that they “possess” them. First,

look to drug residue, present on up to 80 percent of

currency. Caballes, 543 U.S. at 412 (Souter, J., dissenting)

(collecting cases and studies). Drug residue can also

sometimes even be unknowingly present on clothing and

in vehicles. Richard E. Myers II, Detector Dogs and

Probable Cause, 14 Geo. Mason L. Rev. 1, 4–5 (2006).

Possession of residue is a crime on the state level—but

only if the possession is knowing. Those who unknowingly

possess residue should have a reasonable and legitimate

expectation of privacy; they fall outside Caballes’s

premise that the person is guilty of a crime and within its

premise that lawful activity in the home does enjoy

protection.

The home presents particular hazards for housing

drugs completely unbeknownst to an innocent

19

homeowner—in ways that trench the very values of

security and privacy the home protects. Imagine someone

has a party or a few houseguests. A guest uses drugs in

the bathroom, or bedroom, and leaves some behind,

perhaps even just medical marijuana. See Morgan Smith,

Beware of the Drug Detection Dog: The Fourth

Amendment, Drug Detection Dogs, and State

Legalization of Marijuana, 73 SMU L. Rev. 611, 631

(2020). The next day, a drug sniffing dog would alert to

the apartment. Is the apartment owner’s privacy intruded

upon? Yes. A resident, especially one who lives in cityowned housing where police and their dogs may roam

without resident consent, will now have to frisk all guests

for drugs. And after any visit, and certainly after larger

gatherings, he will have to sweep his home. Or he could

limit whom he invites, or even decide to live in solitude, as

that may be the only option that protects his privacy.

Those renting a furnished apartment, or staying even one

night in a hotel room, will need to bring their own dog to

sweep for drugs to make the room safe and secure. These

effects are all privacy intrusions—as well as free

association incursions, equally protected by the Fourth

Amendment.

Thus, even if it is true a person has no legitimate

expectation of privacy in drugs he knowingly possesses—

after all, he has control and can choose not to possess

them—he does have a legitimate expectation of privacy in

drugs he unknowingly possesses. The rule announced by

the decision below infringes on that legitimate expectation

of privacy. Only this Court’s intervention can restore the

Fourth Amendment’s protections.

20

CONCLUSION

The petition for a writ of certiorari should be granted.

Respectfully submitted.

NICOLE L. MASIELLO

Counsel of Record

ARNOLD & PORTER

KAYE SCHOLER LLP

250 West 55th Street

New York, NY 10019

(212) 836-8000

nicole.masiello@arnoldporter.com

R. STANTON JONES

ARNOLD & PORTER

KAYE SCHOLER LLP

601 Massachusetts Ave., NW

Washington, DC 20001

(202) 942-5000

FEBRUARY 2026