(Slip Opinion)              OCTOBER TERM, 2015                                       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

                             UTAH v. STRIEFF

          CERTIORARI TO THE SUPREME COURT OF UTAH

   No. 14–1373. Argued February 22, 2016—Decided June 20, 2016
Narcotics detective Douglas Fackrell conducted surveillance on a South
 Salt Lake City residence based on an anonymous tip about drug ac-
 tivity. The number of people he observed making brief visits to the
 house over the course of a week made him suspicious that the occu-
 pants were dealing drugs. After observing respondent Edward Strieff
 leave the residence, Officer Fackrell detained Strieff at a nearby
 parking lot, identifying himself and asking Strieff what he was doing
 at the house. He then requested Strieff’s identification and relayed
 the information to a police dispatcher, who informed him that Strieff
 had an outstanding arrest warrant for a traffic violation. Officer
 Fackrell arrested Strieff, searched him, and found methamphetamine
 and drug paraphernalia. Strieff moved to suppress the evidence, ar-
 guing that it was derived from an unlawful investigatory stop. The
 trial court denied the motion, and the Utah Court of Appeals af-
 firmed. The Utah Supreme Court reversed, however, and ordered the
 evidence suppressed.
Held: The evidence Officer Fackrell seized incident to Strieff’s arrest is
 admissible based on an application of the attenuation factors from
 Brown v. Illinois, 422 U. S. 590. In this case, there was no flagrant
 police misconduct. Therefore, Officer Fackrell’s discovery of a valid,
 pre-existing, and untainted arrest warrant attenuated the connection
 between the unconstitutional investigatory stop and the evidence
 seized incident to a lawful arrest. Pp. 4–10.
    (a) As the primary judicial remedy for deterring Fourth Amend-
 ment violations, the exclusionary rule encompasses both the “primary
 evidence obtained as a direct result of an illegal search or seizure”
 and, relevant here, “evidence later discovered and found to be deriva-
 tive of an illegality.” Segura v. United States, 468 U. S. 796, 804.
 But to ensure that those deterrence benefits are not outweighed by
2                           UTAH v. STRIEFF

                                  Syllabus

    the rule’s substantial social costs, there are several exceptions to the
    rule. One exception is the attenuation doctrine, which provides for
    admissibility when the connection between unconstitutional police
    conduct and the evidence is sufficiently remote or has been interrupt-
    ed by some intervening circumstance. See Hudson v. Michigan, 547
    U. S. 586, 593. Pp. 4–5.
       (b) As a threshold matter, the attenuation doctrine is not limited to
    the defendant’s independent acts. The doctrine therefore applies
    here, where the intervening circumstance is the discovery of a valid,
    pre-existing, and untainted arrest warrant. Assuming, without de-
    ciding, that Officer Fackrell lacked reasonable suspicion to stop
    Strieff initially, the discovery of that arrest warrant attenuated the
    connection between the unlawful stop and the evidence seized from
    Strieff incident to his arrest. Pp. 5–10.
         (1) Three factors articulated in Brown v. Illinois, 422 U. S. 590,
    lead to this conclusion. The first, “temporal proximity” between the
    initially unlawful stop and the search, id., at 603, favors suppressing
    the evidence. Officer Fackrell discovered drug contraband on Strieff
    only minutes after the illegal stop. In contrast, the second factor,
    “the presence of intervening circumstances, id., at 603–604, strongly
    favors the State. The existence of a valid warrant, predating the in-
    vestigation and entirely unconnected with the stop, favors finding
    sufficient attenuation between the unlawful conduct and the discov-
    ery of evidence. That warrant authorized Officer Fackrell to arrest
    Strieff, and once the arrest was authorized, his search of Strieff inci-
    dent to that arrest was undisputedly lawful. The third factor, “the
    purpose and flagrancy of the official misconduct,” id., at 604, also
    strongly favors the State. Officer Fackrell was at most negligent, but
    his errors in judgment hardly rise to a purposeful or flagrant viola-
    tion of Strieff’s Fourth Amendment rights. After the unlawful stop,
    his conduct was lawful, and there is no indication that the stop was
    part of any systemic or recurrent police misconduct. Pp. 6–9.
         (2) Strieff’s counterarguments are unpersuasive. First, neither
    Officer Fackrell’s purpose nor the flagrancy of the violation rises to a
    level of misconduct warranting suppression. Officer Fackrell’s pur-
    pose was not to conduct a suspicionless fishing expedition but was to
    gather information about activity inside a house whose occupants
    were legitimately suspected of dealing drugs. Strieff conflates the
    standard for an illegal stop with the standard for flagrancy, which
    requires more than the mere absence of proper cause. Second, it is
    unlikely that the prevalence of outstanding warrants will lead to
    dragnet searches by police. Such misconduct would expose police to
    civil liability and, in any event, is already accounted for by Brown’s
    “purpose and flagrancy” factor. Pp. 9–10.
                     Cite as: 579 U. S. ____ (2016)                     3

                                Syllabus

2015 UT 2, 357 P. 3d 532, reversed.

   THOMAS, J., delivered the opinion of the Court, in which ROBERTS,
C. J., and KENNEDY, BREYER, and ALITO, JJ., joined. SOTOMAYOR, J.,
filed a dissenting opinion, in which GINSBURG, J., joined as to Parts I,
II, and III. KAGAN, J., filed a dissenting opinion, in which GINSBURG, J.,
joined.
                        Cite as: 579 U. S. ____ (2016)                              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. 14–1373
                                   _________________


               UTAH, PETITIONER v. EDWARD 

                  JOSEPH STRIEFF, JR. 

 ON WRIT OF CERTIORARI TO THE SUPREME COURT OF UTAH
                                 [June 20, 2016]

   JUSTICE THOMAS delivered the opinion of the Court.
   To enforce the Fourth Amendment’s prohibition against
“unreasonable searches and seizures,” this Court has at
times required courts to exclude evidence obtained by
unconstitutional police conduct. But the Court has also
held that, even when there is a Fourth Amendment viola-
tion, this exclusionary rule does not apply when the costs
of exclusion outweigh its deterrent benefits. In some
cases, for example, the link between the unconstitutional
conduct and the discovery of the evidence is too attenuated
to justify suppression. The question in this case is whether
this attenuation doctrine applies when an officer makes
an unconstitutional investigatory stop; learns during that
stop that the suspect is subject to a valid arrest warrant;
and proceeds to arrest the suspect and seize incriminating
evidence during a search incident to that arrest. We hold
that the evidence the officer seized as part of the search
incident to arrest is admissible because the officer’s dis-
covery of the arrest warrant attenuated the connection
between the unlawful stop and the evidence seized inci-
dent to arrest.
2                     UTAH v. STRIEFF

                     Opinion of the Court 


                               I

  This case began with an anonymous tip. In December
2006, someone called the South Salt Lake City police’s
drug-tip line to report “narcotics activity” at a particular
residence. App. 15. Narcotics detective Douglas Fackrell
investigated the tip. Over the course of about a week,
Officer Fackrell conducted intermittent surveillance of the
home. He observed visitors who left a few minutes after
arriving at the house. These visits were sufficiently fre-
quent to raise his suspicion that the occupants were deal-
ing drugs.
  One of those visitors was respondent Edward Strieff.
Officer Fackrell observed Strieff exit the house and walk
toward a nearby convenience store. In the store’s parking
lot, Officer Fackrell detained Strieff, identified himself,
and asked Strieff what he was doing at the residence.
  As part of the stop, Officer Fackrell requested Strieff ’s
identification, and Strieff produced his Utah identification
card. Officer Fackrell relayed Strieff ’s information to a
police dispatcher, who reported that Strieff had an out-
standing arrest warrant for a traffic violation. Officer
Fackrell then arrested Strieff pursuant to that warrant.
When Officer Fackrell searched Strieff incident to the
arrest, he discovered a baggie of methamphetamine and
drug paraphernalia.
  The State charged Strieff with unlawful possession of
methamphetamine and drug paraphernalia. Strieff moved
to suppress the evidence, arguing that the evidence was
inadmissible because it was derived from an unlawful
investigatory stop. At the suppression hearing, the prose-
cutor conceded that Officer Fackrell lacked reasonable
suspicion for the stop but argued that the evidence should
not be suppressed because the existence of a valid arrest
warrant attenuated the connection between the unlawful
stop and the discovery of the contraband.
  The trial court agreed with the State and admitted the
                 Cite as: 579 U. S. ____ (2016)            3

                     Opinion of the Court

evidence. The court found that the short time between the
illegal stop and the search weighed in favor of suppressing
the evidence, but that two countervailing considerations
made it admissible. First, the court considered the pres-
ence of a valid arrest warrant to be an “ ‘extraordinary
intervening circumstance.’ ” App. to Pet. for Cert. 102
(quoting United States v. Simpson, 439 F. 3d 490, 496
(CA8 2006). Second, the court stressed the absence of
flagrant misconduct by Officer Fackrell, who was conduct-
ing a legitimate investigation of a suspected drug house.
   Strieff conditionally pleaded guilty to reduced charges of
attempted possession of a controlled substance and pos-
session of drug paraphernalia, but reserved his right to
appeal the trial court’s denial of the suppression motion.
The Utah Court of Appeals affirmed. 2012 UT App 245,
286 P. 3d 317.
   The Utah Supreme Court reversed. 2015 UT 2, 357
P. 3d 532. It held that the evidence was inadmissible
because only “a voluntary act of a defendant’s free will (as
in a confession or consent to search)” sufficiently breaks
the connection between an illegal search and the discovery
of evidence. Id., at 536. Because Officer Fackrell’s discov-
ery of a valid arrest warrant did not fit this description,
the court ordered the evidence suppressed. Ibid.
   We granted certiorari to resolve disagreement about
how the attenuation doctrine applies where an unconstitu-
tional detention leads to the discovery of a valid arrest
warrant. 576 U. S. ___ (2015). Compare, e.g., United
States v. Green, 111 F. 3d 515, 522–523 (CA7 1997) (hold-
ing that discovery of the warrant is a dispositive interven-
ing circumstance where police misconduct was not fla-
grant), with, e.g., State v. Moralez, 297 Kan. 397, 415, 300
P. 3d 1090, 1102 (2013) (assigning little significance to the
discovery of the warrant). We now reverse.
4                     UTAH v. STRIEFF

                     Opinion of the Court

                               II

                               A

   The Fourth Amendment protects “[t]he right of the
people to be secure in their persons, houses, papers, and
effects, against unreasonable searches and seizures.”
Because officers who violated the Fourth Amendment
were traditionally considered trespassers, individuals
subject to unconstitutional searches or seizures histori-
cally enforced their rights through tort suits or self-help.
Davies, Recovering the Original Fourth Amendment, 98
Mich. L. Rev. 547, 625 (1999). In the 20th century, how-
ever, the exclusionary rule—the rule that often requires
trial courts to exclude unlawfully seized evidence in a
criminal trial—became the principal judicial remedy to
deter Fourth Amendment violations. See, e.g., Mapp v.
Ohio, 367 U. S. 643, 655 (1961).
   Under the Court’s precedents, the exclusionary rule
encompasses both the “primary evidence obtained as a
direct result of an illegal search or seizure” and, relevant
here, “evidence later discovered and found to be derivative
of an illegality,” the so-called “ ‘fruit of the poisonous
tree.’ ” Segura v. United States, 468 U. S. 796, 804 (1984).
But the significant costs of this rule have led us to deem it
“applicable only . . . where its deterrence benefits outweigh
its substantial social costs.” Hudson v. Michigan, 547
U. S. 586, 591 (2006) (internal quotation marks omitted).
“Suppression of evidence . . . has always been our last
resort, not our first impulse.” Ibid.
   We have accordingly recognized several exceptions to
the rule. Three of these exceptions involve the causal
relationship between the unconstitutional act and the
discovery of evidence. First, the independent source doc-
trine allows trial courts to admit evidence obtained in an
unlawful search if officers independently acquired it from
a separate, independent source. See Murray v. United
States, 487 U. S. 533, 537 (1988). Second, the inevitable
                 Cite as: 579 U. S. ____ (2016)            5

                     Opinion of the Court

discovery doctrine allows for the admission of evidence
that would have been discovered even without the uncon-
stitutional source. See Nix v. Williams, 467 U. S. 431,
443–444 (1984). Third, and at issue here, is the attenua-
tion doctrine: Evidence is admissible when the connection
between unconstitutional police conduct and the evidence
is remote or has been interrupted by some intervening
circumstance, so that “the interest protected by the consti-
tutional guarantee that has been violated would not be
served by suppression of the evidence obtained.” Hudson,
supra, at 593.
                              B
  Turning to the application of the attenuation doctrine to
this case, we first address a threshold question: whether
this doctrine applies at all to a case like this, where the
intervening circumstance that the State relies on is the
discovery of a valid, pre-existing, and untainted arrest
warrant. The Utah Supreme Court declined to apply the
attenuation doctrine because it read our precedents as
applying the doctrine only “to circumstances involving an
independent act of a defendant’s ‘free will’ in confessing to
a crime or consenting to a search.” 357 P. 3d, at 544. In
this Court, Strieff has not defended this argument, and we
disagree with it, as well. The attenuation doctrine evalu-
ates the causal link between the government’s unlawful
act and the discovery of evidence, which often has nothing
to do with a defendant’s actions. And the logic of our prior
attenuation cases is not limited to independent acts by the
defendant.
  It remains for us to address whether the discovery of a
valid arrest warrant was a sufficient intervening event to
break the causal chain between the unlawful stop and the
discovery of drug-related evidence on Strieff ’s person. The
three factors articulated in Brown v. Illinois, 422 U. S. 590
(1975), guide our analysis. First, we look to the “temporal
6                    UTAH v. STRIEFF

                     Opinion of the Court

proximity” between the unconstitutional conduct and the
discovery of evidence to determine how closely the discov-
ery of evidence followed the unconstitutional search. Id.,
at 603. Second, we consider “the presence of intervening
circumstances.” Id., at 603–604. Third, and “particularly”
significant, we examine “the purpose and flagrancy of the
official misconduct.” Id., at 604. In evaluating these
factors, we assume without deciding (because the State
conceded the point) that Officer Fackrell lacked reasonable
suspicion to initially stop Strieff. And, because we ulti-
mately conclude that the warrant breaks the causal chain,
we also have no need to decide whether the warrant’s
existence alone would make the initial stop constitutional
even if Officer Fackrell was unaware of its existence.
                              1
   The first factor, temporal proximity between the ini-
tially unlawful stop and the search, favors suppressing the
evidence. Our precedents have declined to find that this
factor favors attenuation unless “substantial time” elapses
between an unlawful act and when the evidence is ob-
tained. Kaupp v. Texas, 538 U. S. 626, 633 (2003) ( per
curiam). Here, however, Officer Fackrell discovered drug
contraband on Strieff ’s person only minutes after the
illegal stop. See App. 18–19. As the Court explained in
Brown, such a short time interval counsels in favor of
suppression; there, we found that the confession should be
suppressed, relying in part on the “less than two hours”
that separated the unconstitutional arrest and the confes-
sion. 422 U. S., at 604.
   In contrast, the second factor, the presence of interven-
ing circumstances, strongly favors the State. In Segura,
468 U. S. 796, the Court addressed similar facts to those
here and found sufficient intervening circumstances to
allow the admission of evidence. There, agents had proba-
ble cause to believe that apartment occupants were deal-
                 Cite as: 579 U. S. ____ (2016)            7

                     Opinion of the Court

ing cocaine. Id., at 799–800. They sought a warrant. In
the meantime, they entered the apartment, arrested an
occupant, and discovered evidence of drug activity during
a limited search for security reasons. Id., at 800–801. The
next evening, the Magistrate Judge issued the search
warrant. Ibid. This Court deemed the evidence admissi-
ble notwithstanding the illegal search because the infor-
mation supporting the warrant was “wholly unconnected
with the [arguably illegal] entry and was known to the
agents well before the initial entry.” Id., at 814.
   Segura, of course, applied the independent source doc-
trine because the unlawful entry “did not contribute in
any way to discovery of the evidence seized under the
warrant.” Id., at 815. But the Segura Court suggested
that the existence of a valid warrant favors finding that
the connection between unlawful conduct and the discov-
ery of evidence is “sufficiently attenuated to dissipate the
taint.” Ibid. That principle applies here.
   In this case, the warrant was valid, it predated Officer
Fackrell’s investigation, and it was entirely unconnected
with the stop. And once Officer Fackrell discovered the
warrant, he had an obligation to arrest Strieff. “A war-
rant is a judicial mandate to an officer to conduct a search
or make an arrest, and the officer has a sworn duty to
carry out its provisions.” United States v. Leon, 468 U. S.
897, 920, n. 21 (1984) (internal quotation marks omitted).
Officer Fackrell’s arrest of Strieff thus was a ministerial
act that was independently compelled by the pre-existing
warrant. And once Officer Fackrell was authorized to
arrest Strieff, it was undisputedly lawful to search Strieff
as an incident of his arrest to protect Officer Fackrell’s
safety. See Arizona v. Gant, 556 U. S. 332, 339 (2009)
(explaining the permissible scope of searches incident to
arrest).
   Finally, the third factor, “the purpose and flagrancy of
the official misconduct,” Brown, supra, at 604, also strongly
8                     UTAH v. STRIEFF

                     Opinion of the Court

favors the State. The exclusionary rule exists to deter
police misconduct. Davis v. United States, 564 U. S. 229,
236–237 (2011). The third factor of the attenuation doc-
trine reflects that rationale by favoring exclusion only
when the police misconduct is most in need of deter-
rence—that is, when it is purposeful or flagrant.
   Officer Fackrell was at most negligent. In stopping
Strieff, Officer Fackrell made two good-faith mistakes.
First, he had not observed what time Strieff entered the
suspected drug house, so he did not know how long Strieff
had been there. Officer Fackrell thus lacked a sufficient
basis to conclude that Strieff was a short-term visitor who
may have been consummating a drug transaction. Second,
because he lacked confirmation that Strieff was a short-
term visitor, Officer Fackrell should have asked Strieff
whether he would speak with him, instead of demanding
that Strieff do so. Officer Fackrell’s stated purpose was to
“find out what was going on [in] the house.” App. 17.
Nothing prevented him from approaching Strieff simply to
ask. See Florida v. Bostick, 501 U. S. 429, 434 (1991) (“[A]
seizure does not occur simply because a police officer
approaches an individual and asks a few questions”). But
these errors in judgment hardly rise to a purposeful or
flagrant violation of Strieff ’s Fourth Amendment rights.
   While Officer Fackrell’s decision to initiate the stop was
mistaken, his conduct thereafter was lawful. The officer’s
decision to run the warrant check was a “negligibly bur-
densome precautio[n]” for officer safety. Rodriguez v.
United States, 575 U. S. ___, ___ (2015) (slip op., at 7).
And Officer Fackrell’s actual search of Strieff was a lawful
search incident to arrest. See Gant, supra, at 339.
   Moreover, there is no indication that this unlawful stop
was part of any systemic or recurrent police misconduct.
To the contrary, all the evidence suggests that the stop
was an isolated instance of negligence that occurred in
connection with a bona fide investigation of a suspected
                  Cite as: 579 U. S. ____ (2016)             9

                      Opinion of the Court

drug house. Officer Fackrell saw Strieff leave a suspected
drug house. And his suspicion about the house was based
on an anonymous tip and his personal observations.
   Applying these factors, we hold that the evidence dis-
covered on Strieff ’s person was admissible because the
unlawful stop was sufficiently attenuated by the pre-
existing arrest warrant. Although the illegal stop was
close in time to Strieff ’s arrest, that consideration is out-
weighed by two factors supporting the State. The out-
standing arrest warrant for Strieff ’s arrest is a critical
intervening circumstance that is wholly independent of
the illegal stop. The discovery of that warrant broke the
causal chain between the unconstitutional stop and the
discovery of evidence by compelling Officer Fackrell to
arrest Strieff. And, it is especially significant that there is
no evidence that Officer Fackrell’s illegal stop reflected
flagrantly unlawful police misconduct.
                              2
  We find Strieff ’s counterarguments unpersuasive.
  First, he argues that the attenuation doctrine should not
apply because the officer’s stop was purposeful and fla-
grant. He asserts that Officer Fackrell stopped him solely
to fish for evidence of suspected wrongdoing. But Officer
Fackrell sought information from Strieff to find out what
was happening inside a house whose occupants were
legitimately suspected of dealing drugs. This was not a
suspicionless fishing expedition “in the hope that some-
thing would turn up.” Taylor v. Alabama, 457 U. S. 687,
691 (1982).
  Strieff argues, moreover, that Officer Fackrell’s conduct
was flagrant because he detained Strieff without the
necessary level of cause (here, reasonable suspicion). But
that conflates the standard for an illegal stop with the
standard for flagrancy. For the violation to be flagrant,
more severe police misconduct is required than the mere
10                    UTAH v. STRIEFF

                     Opinion of the Court

absence of proper cause for the seizure. See, e.g., Kaupp,
538 U. S., at 628, 633 (finding flagrant violation where a
warrantless arrest was made in the arrestee’s home after
police were denied a warrant and at least some officers
knew they lacked probable cause). Neither the officer’s
alleged purpose nor the flagrancy of the violation rise to a
level of misconduct to warrant suppression.
  Second, Strieff argues that, because of the prevalence of
outstanding arrest warrants in many jurisdictions, police
will engage in dragnet searches if the exclusionary rule is
not applied. We think that this outcome is unlikely. Such
wanton conduct would expose police to civil liability. See
42 U. S. C. §1983; Monell v. New York City Dept. of Social
Servs., 436 U. S. 658, 690 (1978); see also Segura, 468
U. S., at 812. And in any event, the Brown factors take
account of the purpose and flagrancy of police misconduct.
Were evidence of a dragnet search presented here, the
application of the Brown factors could be different. But
there is no evidence that the concerns that Strieff raises
with the criminal justice system are present in South Salt
Lake City, Utah.
                        *    *     *
  We hold that the evidence Officer Fackrell seized as part
of his search incident to arrest is admissible because his
discovery of the arrest warrant attenuated the connection
between the unlawful stop and the evidence seized from
Strieff incident to arrest. The judgment of the Utah Su-
preme Court, accordingly, is reversed.
                                           It is so ordered.
                 Cite as: 579 U. S. ____ (2016)            1

                   SOTOMAYOR, J., dissenting

SUPREME COURT OF THE UNITED STATES
                         _________________

                         No. 14–1373
                         _________________


            UTAH, PETITIONER v. EDWARD 

               JOSEPH STRIEFF, JR. 

 ON WRIT OF CERTIORARI TO THE SUPREME COURT OF UTAH
                        [June 20, 2016]

   JUSTICE SOTOMAYOR, with whom JUSTICE GINSBURG
joins as to Parts I, II, and III, dissenting.
   The Court today holds that the discovery of a warrant
for an unpaid parking ticket will forgive a police officer’s
violation of your Fourth Amendment rights. Do not be
soothed by the opinion’s technical language: This case
allows the police to stop you on the street, demand your
identification, and check it for outstanding traffic war­
rants—even if you are doing nothing wrong. If the officer
discovers a warrant for a fine you forgot to pay, courts will
now excuse his illegal stop and will admit into evidence
anything he happens to find by searching you after arrest­
ing you on the warrant. Because the Fourth Amendment
should prohibit, not permit, such misconduct, I dissent.
                              I
  Minutes after Edward Strieff walked out of a South Salt
Lake City home, an officer stopped him, questioned him,
and took his identification to run it through a police data­
base. The officer did not suspect that Strieff had done
anything wrong. Strieff just happened to be the first
person to leave a house that the officer thought might
contain “drug activity.” App. 16–19.
  As the State of Utah concedes, this stop was illegal.
App. 24. The Fourth Amendment protects people from
“unreasonable searches and seizures.” An officer breaches
2                     UTAH v. STRIEFF

                   SOTOMAYOR, J., dissenting

that protection when he detains a pedestrian to check his
license without any evidence that the person is engaged in
a crime. Delaware v. Prouse, 440 U. S. 648, 663 (1979);
Terry v. Ohio, 392 U. S. 1, 21 (1968). The officer deepens
the breach when he prolongs the detention just to fish
further for evidence of wrongdoing. Rodriguez v. United
States, 575 U. S. ___, ___–___ (2015) (slip op., at 6–7). In
his search for lawbreaking, the officer in this case himself
broke the law.
   The officer learned that Strieff had a “small traffic
warrant.” App. 19. Pursuant to that warrant, he arrested
Strieff and, conducting a search incident to the arrest,
discovered methamphetamine in Strieff ’s pockets.
   Utah charged Strieff with illegal drug possession. Be­
fore trial, Strieff argued that admitting the drugs into
evidence would condone the officer’s misbehavior. The
methamphetamine, he reasoned, was the product of the
officer’s illegal stop. Admitting it would tell officers that
unlawfully discovering even a “small traffic warrant”
would give them license to search for evidence of unrelated
offenses. The Utah Supreme Court unanimously agreed
with Strieff. A majority of this Court now reverses.
                               II
  It is tempting in a case like this, where illegal conduct
by an officer uncovers illegal conduct by a civilian, to
forgive the officer. After all, his instincts, although uncon­
stitutional, were correct. But a basic principle lies at the
heart of the Fourth Amendment: Two wrongs don’t make a
right. See Weeks v. United States, 232 U. S. 383, 392
(1914). When “lawless police conduct” uncovers evidence
of lawless civilian conduct, this Court has long required
later criminal trials to exclude the illegally obtained evi­
dence. Terry, 392 U. S., at 12; Mapp v. Ohio, 367 U. S.
643, 655 (1961). For example, if an officer breaks into a
home and finds a forged check lying around, that check
                  Cite as: 579 U. S. ____ (2016)            3

                   SOTOMAYOR, J., dissenting

may not be used to prosecute the homeowner for bank
fraud. We would describe the check as “ ‘fruit of the poi­
sonous tree.’ ” Wong Sun v. United States, 371 U. S. 471,
488 (1963). Fruit that must be cast aside includes not
only evidence directly found by an illegal search but also
evidence “come at by exploitation of that illegality.” Ibid.
   This “exclusionary rule” removes an incentive for offic­
ers to search us without proper justification. Terry, 392
U. S., at 12. It also keeps courts from being “made party
to lawless invasions of the constitutional rights of citizens
by permitting unhindered governmental use of the fruits
of such invasions.” Id., at 13. When courts admit only
lawfully obtained evidence, they encourage “those who
formulate law enforcement polices, and the officers who
implement them, to incorporate Fourth Amendment ideals
into their value system.” Stone v. Powell, 428 U. S. 465,
492 (1976). But when courts admit illegally obtained
evidence as well, they reward “manifest neglect if not an
open defiance of the prohibitions of the Constitution.”
Weeks, 232 U. S., at 394.
   Applying the exclusionary rule, the Utah Supreme
Court correctly decided that Strieff ’s drugs must be ex­
cluded because the officer exploited his illegal stop to
discover them. The officer found the drugs only after
learning of Strieff ’s traffic violation; and he learned of
Strieff ’s traffic violation only because he unlawfully
stopped Strieff to check his driver’s license.
   The court also correctly rejected the State’s argument
that the officer’s discovery of a traffic warrant unspoiled
the poisonous fruit. The State analogizes finding the
warrant to one of our earlier decisions, Wong Sun v. United
States. There, an officer illegally arrested a person
who, days later, voluntarily returned to the station to
confess to committing a crime. 371 U. S., at 491. Even
though the person would not have confessed “but for the
illegal actions of the police,” id., at 488, we noted that the
4                     UTAH v. STRIEFF

                   SOTOMAYOR, J., dissenting

police did not exploit their illegal arrest to obtain the
confession, id., at 491. Because the confession was ob­
tained by “means sufficiently distinguishable” from the
constitutional violation, we held that it could be admitted
into evidence. Id., at 488, 491. The State contends that
the search incident to the warrant-arrest here is similarly
distinguishable from the illegal stop.
   But Wong Sun explains why Strieff ’s drugs must be
excluded. We reasoned that a Fourth Amendment viola­
tion may not color every investigation that follows but it
certainly stains the actions of officers who exploit the
infraction. We distinguished evidence obtained by innocu­
ous means from evidence obtained by exploiting miscon­
duct after considering a variety of factors: whether a long
time passed, whether there were “intervening circum­
stances,” and whether the purpose or flagrancy of the
misconduct was “calculated” to procure the evidence.
Brown v. Illinois, 422 U. S. 590, 603–604 (1975).
   These factors confirm that the officer in this case discov­
ered Strieff ’s drugs by exploiting his own illegal conduct.
The officer did not ask Strieff to volunteer his name only
to find out, days later, that Strieff had a warrant against
him. The officer illegally stopped Strieff and immediately
ran a warrant check. The officer’s discovery of a warrant
was not some intervening surprise that he could not have
anticipated. Utah lists over 180,000 misdemeanor war­
rants in its database, and at the time of the arrest, Salt
Lake County had a “backlog of outstanding warrants”
so large that it faced the “potential for civil liability.”
See Dept. of Justice, Bureau of Justice Statistics,
Survey of State Criminal History Information Systems,
2014 (2015) (Systems Survey) (Table 5a), online at
https://www.ncjrs.gov/pdffiles1/bjs/grants/249799.pdf (all
Internet materials as last visited June 16, 2016); Inst.
for Law and Policy Planning, Salt Lake County Crim-
inal Justice System Assessment 6.7 (2004), online at
                  Cite as: 579 U. S. ____ (2016)              5

                    SOTOMAYOR, J., dissenting

http://www. slco.org / cjac / resources / SaltLakeCJSAfinal.pdf.
The officer’s violation was also calculated to procure evi­
dence. His sole reason for stopping Strieff, he acknowl­
edged, was investigative—he wanted to discover whether
drug activity was going on in the house Strieff had just
exited. App. 17.
  The warrant check, in other words, was not an “inter­
vening circumstance” separating the stop from the search
for drugs. It was part and parcel of the officer’s illegal
“expedition for evidence in the hope that something might
turn up.” Brown, 422 U. S., at 605. Under our precedents,
because the officer found Strieff ’s drugs by exploiting his
own constitutional violation, the drugs should be excluded.
                             III

                              A

  The Court sees things differently. To the Court, the fact
that a warrant gives an officer cause to arrest a person
severs the connection between illegal policing and the
resulting discovery of evidence. Ante, at 7. This is a re­
markable proposition: The mere existence of a warrant not
only gives an officer legal cause to arrest and search a
person, it also forgives an officer who, with no knowledge
of the warrant at all, unlawfully stops that person on a
whim or hunch.
  To explain its reasoning, the Court relies on Segura v.
United States, 468 U. S. 796 (1984). There, federal agents
applied for a warrant to search an apartment but illegally
entered the apartment to secure it before the judge issued
the warrant. Id., at 800–801. After receiving the warrant,
the agents then searched the apartment for drugs. Id., at
801. The question before us was what to do with the
evidence the agents then discovered. We declined to sup­
press it because “[t]he illegal entry into petitioners’
apartment did not contribute in any way to discovery of
the evidence seized under the warrant.” Id., at 815.
6                      UTAH v. STRIEFF

                    SOTOMAYOR, J., dissenting

   According to the majority, Segura involves facts “simi­
lar” to this case and “suggest[s]” that a valid warrant will
clean up whatever illegal conduct uncovered it. Ante, at
6–7. It is difficult to understand this interpretation. In
Segura, the agents’ illegal conduct in entering the apart­
ment had nothing to do with their procurement of a search
warrant. Here, the officer’s illegal conduct in stopping
Strieff was essential to his discovery of an arrest warrant.
Segura would be similar only if the agents used infor­
mation they illegally obtained from the apartment to
procure a search warrant or discover an arrest warrant.
Precisely because that was not the case, the Court admit­
ted the untainted evidence. 468 U. S., at 814.
   The majority likewise misses the point when it calls the
warrant check here a “ ‘negligibly burdensome precau­
tio[n]’ ” taken for the officer’s “safety.” Ante, at 8 (quoting
Rodriguez, 575 U. S., at ___ (slip op., at 7)). Remember,
the officer stopped Strieff without suspecting him of com­
mitting any crime. By his own account, the officer did not
fear Strieff. Moreover, the safety rationale we discussed
in Rodriguez, an opinion about highway patrols, is con­
spicuously absent here. A warrant check on a highway
“ensur[es] that vehicles on the road are operated safely
and responsibly.” Id., at ___ (slip op., at 6). We allow such
checks during legal traffic stops because the legitimacy of
a person’s driver’s license has a “close connection to road­
way safety.” Id., at ___ (slip op., at 7). A warrant check of
a pedestrian on a sidewalk, “by contrast, is a measure
aimed at ‘detect[ing] evidence of ordinary criminal wrong­
doing.’ ” Ibid. (quoting Indianapolis v. Edmond, 531 U. S.
32, 40–41 (2000)). Surely we would not allow officers to
warrant-check random joggers, dog walkers, and lemonade
vendors just to ensure they pose no threat to anyone else.
   The majority also posits that the officer could not have
exploited his illegal conduct because he did not violate the
Fourth Amendment on purpose. Rather, he made “good­
                 Cite as: 579 U. S. ____ (2016)           7

                   SOTOMAYOR, J., dissenting

faith mistakes.” Ante, at 8. Never mind that the officer’s
sole purpose was to fish for evidence. The majority casts
his unconstitutional actions as “negligent” and therefore
incapable of being deterred by the exclusionary rule. Ibid.
  But the Fourth Amendment does not tolerate an officer’s
unreasonable searches and seizures just because he did
not know any better. Even officers prone to negligence can
learn from courts that exclude illegally obtained evidence.
Stone, 428 U. S., at 492. Indeed, they are perhaps the
most in need of the education, whether by the judge’s
opinion, the prosecutor’s future guidance, or an updated
manual on criminal procedure. If the officers are in doubt
about what the law requires, exclusion gives them an
“incentive to err on the side of constitutional behavior.”
United States v. Johnson, 457 U. S. 537, 561 (1982).
                             B
   Most striking about the Court’s opinion is its insistence
that the event here was “isolated,” with “no indication that
this unlawful stop was part of any systemic or recurrent
police misconduct.” Ante, at 8–9. Respectfully, nothing
about this case is isolated.
   Outstanding warrants are surprisingly common. When
a person with a traffic ticket misses a fine payment or
court appearance, a court will issue a warrant. See, e.g.,
Brennan Center for Justice, Criminal Justice Debt 23 (2010),
online at https://www.brennancenter.org/sites/default/
files/legacy/Fees%20and%20Fines%20FINAL.pdf. When a
person on probation drinks alcohol or breaks curfew, a
court will issue a warrant. See, e.g., Human Rights
Watch, Profiting from Probation 1, 51 (2014), online at
https: //www.hrw.org/report/2014/02/05 /profiting-probation/
americas-offender- funded-probation-industry. The States
and Federal Government maintain databases with over
7.8 million outstanding warrants, the vast majority of
which appear to be for minor offenses. See Systems Sur­
8                      UTAH v. STRIEFF

                    SOTOMAYOR, J., dissenting

vey (Table 5a). Even these sources may not track the
“staggering” numbers of warrants, “ ‘drawers and draw­
ers’ ” full, that many cities issue for traffic violations and
ordinance infractions. Dept. of Justice, Civil Rights Div.,
Investigation of the Ferguson Police Department 47, 55
(2015) (Ferguson Report), online at https://www.justice.gov/
sites/default/files/opa/press-releases/attachments / 2015 / 03/
04/ferguson_police_department_report.pdf. The county in
this case has had a “backlog” of such warrants. See supra,
at 4. The Department of Justice recently reported that in
the town of Ferguson, Missouri, with a population of
21,000, 16,000 people had outstanding warrants against
them. Ferguson Report, at 6, 55.
   Justice Department investigations across the country
have illustrated how these astounding numbers of war­
rants can be used by police to stop people without cause.
In a single year in New Orleans, officers “made nearly
60,000 arrests, of which about 20,000 were of people with
outstanding traffic or misdemeanor warrants from neigh­
boring parishes for such infractions as unpaid tickets.”
Dept. of Justice, Civil Rights Div., Investigation of the
New Orleans Police Department 29 (2011), online at
https://www.justice.gov/sites/default/files/crt/legacy/2011/
03/17/nopd_report.pdf. In the St. Louis metropolitan area,
officers “routinely” stop people—on the street, at bus
stops, or even in court—for no reason other than “an of­
ficer’s desire to check whether the subject had a municipal
arrest warrant pending.” Ferguson Report, at 49, 57. In
Newark, New Jersey, officers stopped 52,235 pedestrians
within a 4-year period and ran warrant checks on 39,308
of them. Dept. of Justice, Civil Rights Div., Investigation
of the Newark Police Department 8, 19, n. 15 (2014),
online at https: // www.justice.gov/ sites/default/files/ crt /
legacy/2014/07/22/newark_findings_7-22-14.pdf. The Jus­
tice Department analyzed these warrant-checked stops
and reported that “approximately 93% of the stops would
                  Cite as: 579 U. S. ____ (2016)            9

                   SOTOMAYOR, J., dissenting

have been considered unsupported by articulated reason­
able suspicion.” Id., at 9, n. 7.
   I do not doubt that most officers act in “good faith” and
do not set out to break the law. That does not mean these
stops are “isolated instance[s] of negligence,” however.
Ante, at 8. Many are the product of institutionalized
training procedures. The New York City Police Depart­
ment long trained officers to, in the words of a District
Judge, “stop and question first, develop reasonable suspi­
cion later.” Ligon v. New York, 925 F. Supp. 2d 478, 537–
538 (SDNY), stay granted on other grounds, 736 F. 3d 118
(CA2 2013). The Utah Supreme Court described as “ ‘rou­
tine procedure’ or ‘common practice’ ” the decision of Salt
Lake City police officers to run warrant checks on pedes­
trians they detained without reasonable suspicion. State
v. Topanotes, 2003 UT 30, ¶2, 76 P. 3d 1159, 1160. In the
related context of traffic stops, one widely followed police
manual instructs officers looking for drugs to “run at least
a warrants check on all drivers you stop. Statistically,
narcotics offenders are . . . more likely to fail to appear on
simple citations, such as traffic or trespass violations,
leading to the issuance of bench warrants. Discovery of an
outstanding warrant gives you cause for an immediate
custodial arrest and search of the suspect.” C. Rems-
berg, Tactics for Criminal Patrol 205–206 (1995); C.
Epp et al., Pulled Over 23, 33–36 (2014).
   The majority does not suggest what makes this case
“isolated” from these and countless other examples. Nor
does it offer guidance for how a defendant can prove that
his arrest was the result of “widespread” misconduct.
Surely it should not take a federal investigation of Salt
Lake County before the Court would protect someone in
Strieff ’s position.
                            IV
  Writing only for myself, and drawing on my professional
10                    UTAH v. STRIEFF

                   SOTOMAYOR, J., dissenting

experiences, I would add that unlawful “stops” have severe
consequences much greater than the inconvenience sug­
gested by the name. This Court has given officers an
array of instruments to probe and examine you. When we
condone officers’ use of these devices without adequate
cause, we give them reason to target pedestrians in an
arbitrary manner. We also risk treating members of our
communities as second-class citizens.
   Although many Americans have been stopped for speed­
ing or jaywalking, few may realize how degrading a stop
can be when the officer is looking for more. This Court
has allowed an officer to stop you for whatever reason he
wants—so long as he can point to a pretextual justification
after the fact. Whren v. United States, 517 U. S. 806, 813
(1996). That justification must provide specific reasons
why the officer suspected you were breaking the law,
Terry, 392 U. S., at 21, but it may factor in your ethnicity,
United States v. Brignoni-Ponce, 422 U. S. 873, 886–887
(1975), where you live, Adams v. Williams, 407 U. S. 143,
147 (1972), what you were wearing, United States v.
Sokolow, 490 U. S. 1, 4–5 (1989), and how you behaved,
Illinois v. Wardlow, 528 U. S. 119, 124–125 (2000). The
officer does not even need to know which law you might
have broken so long as he can later point to any possible
infraction—even one that is minor, unrelated, or ambigu­
ous. Devenpeck v. Alford, 543 U. S. 146, 154–155 (2004);
Heien v. North Carolina, 574 U. S. ___ (2014).
   The indignity of the stop is not limited to an officer
telling you that you look like a criminal. See Epp, Pulled
Over, at 5. The officer may next ask for your “consent” to
inspect your bag or purse without telling you that you can
decline. See Florida v. Bostick, 501 U. S. 429, 438 (1991).
Regardless of your answer, he may order you to stand
“helpless, perhaps facing a wall with [your] hands raised.”
Terry, 392 U. S., at 17. If the officer thinks you might be
dangerous, he may then “frisk” you for weapons. This
                 Cite as: 579 U. S. ____ (2016)           11

                   SOTOMAYOR, J., dissenting

involves more than just a pat down. As onlookers pass by,
the officer may “ ‘feel with sensitive fingers every portion
of [your] body. A thorough search [may] be made of [your]
arms and armpits, waistline and back, the groin and area
about the testicles, and entire surface of the legs down to
the feet.’ ” Id., at 17, n. 13.
   The officer’s control over you does not end with the stop.
If the officer chooses, he may handcuff you and take you to
jail for doing nothing more than speeding, jaywalking, or
“driving [your] pickup truck . . . with [your] 3-year-old son
and 5-year-old daughter . . . without [your] seatbelt fas­
tened.” Atwater v. Lago Vista, 532 U. S. 318, 323–324
(2001). At the jail, he can fingerprint you, swab DNA from
the inside of your mouth, and force you to “shower with a
delousing agent” while you “lift [your] tongue, hold out
[your] arms, turn around, and lift [your] genitals.” Flor-
ence v. Board of Chosen Freeholders of County of Burling-
ton, 566 U. S. ___, ___–___ (2012) (slip op., at 2–3); Mary-
land v. King, 569 U. S. ___, ___ (2013) (slip op., at 28).
Even if you are innocent, you will now join the 65 million
Americans with an arrest record and experience the “civil
death” of discrimination by employers, landlords, and
whoever else conducts a background check. Chin, The
New Civil Death, 160 U. Pa. L. Rev. 1789, 1805 (2012); see
J. Jacobs, The Eternal Criminal Record 33–51 (2015);
Young & Petersilia, Keeping Track, 129 Harv. L. Rev.
1318, 1341–1357 (2016). And, of course, if you fail to pay
bail or appear for court, a judge will issue a warrant to
render you “arrestable on sight” in the future.            A.
Goffman, On the Run 196 (2014).
   This case involves a suspicionless stop, one in which the
officer initiated this chain of events without justification.
As the Justice Department notes, supra, at 8, many inno­
cent people are subjected to the humiliations of these
unconstitutional searches. The white defendant in this
case shows that anyone’s dignity can be violated in this
12                    UTAH v. STRIEFF

                   SOTOMAYOR, J., dissenting

manner. See M. Gottschalk, Caught 119–138 (2015). But
it is no secret that people of color are disproportionate
victims of this type of scrutiny. See M. Alexander, The
New Jim Crow 95–136 (2010). For generations, black and
brown parents have given their children “the talk”—
instructing them never to run down the street; always
keep your hands where they can be seen; do not even
think of talking back to a stranger—all out of fear of how
an officer with a gun will react to them. See, e.g., W. E. B.
Du Bois, The Souls of Black Folk (1903); J. Baldwin, The
Fire Next Time (1963); T. Coates, Between the World and
Me (2015).
   By legitimizing the conduct that produces this double
consciousness, this case tells everyone, white and black,
guilty and innocent, that an officer can verify your legal
status at any time. It says that your body is subject to
invasion while courts excuse the violation of your rights.
It implies that you are not a citizen of a democracy but the
subject of a carceral state, just waiting to be cataloged.
   We must not pretend that the countless people who are
routinely targeted by police are “isolated.” They are the
canaries in the coal mine whose deaths, civil and literal,
warn us that no one can breathe in this atmosphere. See
L. Guinier & G. Torres, The Miner’s Canary 274–283
(2002). They are the ones who recognize that unlawful
police stops corrode all our civil liberties and threaten all
our lives. Until their voices matter too, our justice system
will continue to be anything but.
                        *     *      * 

     I dissent.

                 Cite as: 579 U. S. ____ (2016)            1

                     KAGAN, J., dissenting

SUPREME COURT OF THE UNITED STATES
                         _________________

                         No. 14–1373
                         _________________


            UTAH, PETITIONER v. EDWARD 

               JOSEPH STRIEFF, JR. 

 ON WRIT OF CERTIORARI TO THE SUPREME COURT OF UTAH
                        [June 20, 2016]

   JUSTICE KAGAN, with whom JUSTICE GINSBURG joins,
dissenting.
   If a police officer stops a person on the street without
reasonable suspicion, that seizure violates the Fourth
Amendment. And if the officer pats down the unlawfully
detained individual and finds drugs in his pocket, the
State may not use the contraband as evidence in a crimi­
nal prosecution. That much is beyond dispute. The ques­
tion here is whether the prohibition on admitting evidence
dissolves if the officer discovers, after making the stop but
before finding the drugs, that the person has an outstand­
ing arrest warrant. Because that added wrinkle makes no
difference under the Constitution, I respectfully dissent.
   This Court has established a simple framework for
determining whether to exclude evidence obtained
through a Fourth Amendment violation: Suppression is
necessary when, but only when, its societal benefits out­
weigh its costs. See ante, at 4; Davis v. United States, 564
U. S. 229, 237 (2011). The exclusionary rule serves a
crucial function—to deter unconstitutional police conduct.
By barring the use of illegally obtained evidence, courts
reduce the temptation for police officers to skirt the
Fourth Amendment’s requirements. See James v. Illinois,
493 U. S. 307, 319 (1990). But suppression of evidence
also “exacts a heavy toll”: Its consequence in many cases is
to release a criminal without just punishment. Davis, 564
2                     UTAH v. STRIEFF

                     KAGAN, J., dissenting

U. S., at 237. Our decisions have thus endeavored to
strike a sound balance between those two competing
considerations—rejecting the “reflexive” impulse to ex­
clude evidence every time an officer runs afoul of the
Fourth Amendment, id., at 238, but insisting on suppres­
sion when it will lead to “appreciable deterrence” of police
misconduct, Herring v. United States, 555 U. S. 135, 141
(2009).
   This case thus requires the Court to determine whether
excluding the fruits of Officer Douglas Fackrell’s unjusti­
fied stop of Edward Strieff would significantly deter police
from committing similar constitutional violations in the
future. And as the Court states, that inquiry turns on
application of the “attenuation doctrine,” ante, at 5—our
effort to “mark the point” at which the discovery of evi­
dence “become[s] so attenuated” from the police miscon­
duct that the deterrent benefit of exclusion drops below its
cost. United States v. Leon, 468 U. S. 897, 911 (1984).
Since Brown v. Illinois, 422 U. S. 590, 604–605 (1975),
three factors have guided that analysis. First, the closer
the “temporal proximity” between the unlawful act and
the discovery of evidence, the greater the deterrent value
of suppression. Id., at 603. Second, the more “pur­
pose[ful]” or “flagran[t]” the police illegality, the clearer
the necessity, and better the chance, of preventing similar
misbehavior. Id., at 604. And third, the presence (or
absence) of “intervening circumstances” makes a differ­
ence: The stronger the causal chain between the miscon­
duct and the evidence, the more exclusion will curb future
constitutional violations. Id., at 603–604. Here, as shown
below, each of those considerations points toward suppres­
sion: Nothing in Fackrell’s discovery of an outstanding
warrant so attenuated the connection between his wrong­
ful behavior and his detection of drugs as to diminish the
exclusionary rule’s deterrent benefits.
   Start where the majority does: The temporal proximity
                  Cite as: 579 U. S. ____ (2016)               3

                      KAGAN, J., dissenting

factor, it forthrightly admits, “favors suppressing the
evidence.” Ante, at 6. After all, Fackrell’s discovery of
drugs came just minutes after the unconstitutional stop.
And in prior decisions, this Court has made clear that only
the lapse of “substantial time” between the two could favor
admission. Kaupp v. Texas, 538 U. S. 626, 633 (2003) ( per
curiam); see, e.g., Brown, 422 U. S., at 604 (suppressing a
confession when “less than two hours” separated it from
an unlawful arrest). So the State, by all accounts, takes
strike one.
   Move on to the purposefulness of Fackrell’s conduct,
where the majority is less willing to see a problem for
what it is. The majority chalks up Fackrell’s Fourth
Amendment violation to a couple of innocent “mistakes.”
Ante, at 8. But far from a Barney Fife-type mishap,
Fackrell’s seizure of Strieff was a calculated decision,
taken with so little justification that the State has never
tried to defend its legality. At the suppression hearing,
Fackrell acknowledged that the stop was designed for
investigatory purposes—i.e., to “find out what was going
on [in] the house” he had been watching, and to figure out
“what [Strieff] was doing there.” App. 17–18. And
Fackrell frankly admitted that he had no basis for his
action except that Strieff “was coming out of the house.”
Id., at 17. Plug in Fackrell’s and Strieff ’s names, substi­
tute “stop” for “arrest” and “reasonable suspicion” for
“probable cause,” and this Court’s decision in Brown per­
fectly describes this case:
    “[I]t is not disputed that [Fackrell stopped Strieff]
    without [reasonable suspicion]. [He] later testified
    that [he] made the [stop] for the purpose of question­
    ing [Strieff ] as part of [his] investigation . . . . The il­
    legality here . . . had a quality of purposefulness. The
    impropriety of the [stop] was obvious. [A]wareness of
    that fact was virtually conceded by [Fackrell] when
4                     UTAH v. STRIEFF

                     KAGAN, J., dissenting

    [he] repeatedly acknowledged, in [his] testimony, that
    the purpose of [his] action was ‘for investigation’:
    [Fackrell] embarked upon this expedition for evidence
    in the hope that something might turn up.” 422 U. S.,
    at 592, 605 (some internal punctuation altered; foot­
    note, citation, and paragraph break omitted).
In Brown, the Court held those facts to support suppres­
sion—and they do here as well. Swing and a miss for
strike two.
   Finally, consider whether any intervening circumstance
“br[oke] the causal chain” between the stop and the evi­
dence. Ante, at 6. The notion of such a disrupting event
comes from the tort law doctrine of proximate causation.
See Bridge v. Phoenix Bond & Indemnity Co., 553 U. S.
639, 658–659 (2008) (explaining that a party cannot “es­
tablish[ ] proximate cause” when “an intervening cause
break[s] the chain of causation between” the act and the
injury); Kerr, Good Faith, New Law, and the Scope of the
Exclusionary Rule, 99 Geo. L. J. 1077, 1099 (2011) (Fourth
Amendment attenuation analysis “looks to whether the
constitutional violation was the proximate cause of the
discovery of the evidence”). And as in the tort context, a
circumstance counts as intervening only when it is unfore­
seeable—not when it can be seen coming from miles away.
See W. Keeton, D. Dobbs, B. Keeton, & D. Owen, Prosser
and Keeton on Law of Torts 312 (5th ed. 1984). For rather
than breaking the causal chain, predictable effects (e.g., X
leads naturally to Y leads naturally to Z) are its very links.
   And Fackrell’s discovery of an arrest warrant—the only
event the majority thinks intervened—was an eminently
foreseeable consequence of stopping Strieff. As Fackrell
testified, checking for outstanding warrants during a stop
is the “normal” practice of South Salt Lake City police.
App. 18; see also State v. Topanotes, 2003 UT 30, ¶2, 76
P. 3d 1159, 1160 (describing a warrant check as “routine
                     Cite as: 579 U. S. ____ (2016)                     5

                          KAGAN, J., dissenting

procedure” and “common practice” in Salt Lake City). In
other words, the department’s standard detention proce­
dures—stop, ask for identification, run a check—are partly
designed to find outstanding warrants. And find them
they will, given the staggering number of such warrants
on the books. See generally ante, at 7–8 (SOTOMAYOR, J.,
dissenting). To take just a few examples: The State of
California has 2.5 million outstanding arrest warrants (a
number corresponding to about 9% of its adult popula­
tion); Pennsylvania (with a population of about 12.8 mil­
lion) contributes 1.4 million more; and New York City
(population 8.4 million) adds another 1.2 million. See
Reply Brief 8; Associated Press, Pa. Database, NBC News
(Apr. 8, 2007), online at http://goo.gl/3Yq3Nd (as last
visited June 17, 2016); N. Y. Times, Oct. 8, 2015, p. A24.1
So outstanding warrants do not appear as bolts from the
blue. They are the run-of-the-mill results of police stops—
what officers look for when they run a routine check of a
person’s identification and what they know will turn up
with fair regularity. In short, they are nothing like what
intervening circumstances are supposed to be.2 Strike
——————
   1 What is more, outstanding arrest warrants are not distributed evenly

across the population. To the contrary, they are concentrated in
cities, towns, and neighborhoods where stops are most likely to occur—
and so the odds of any given stop revealing a warrant are even higher
than the above numbers indicate. One study found, for example, that
Cincinnati, Ohio had over 100,000 outstanding warrants with only
300,000 residents. See Helland & Tabarrok, The Fugitive: Evidence on
Public Versus Private Law Enforcement from Bail Jumping, 47 J. Law
& Econ. 93, 98 (2004). And as JUSTICE SOTOMAYOR notes, 16,000 of the
21,000 people residing in the town of Ferguson, Missouri have out­
standing warrants. See ante, at 8.
   2 The majority relies on Segura v. United States, 468 U. S. 796 (1984),

to reach the opposite conclusion, see ante, at 6–7, but that decision
lacks any relevance to this case. The Court there held that the Fourth
Amendment violation at issue “did not contribute in any way” to the
police’s subsequent procurement of a warrant and discovery of contra­
band. 468 U. S., at 815. So the Court had no occasion to consider the
6                        UTAH v. STRIEFF

                        KAGAN, J., dissenting

three.
   The majority’s misapplication of Brown’s three-part
inquiry creates unfortunate incentives for the police—
indeed, practically invites them to do what Fackrell did
here. Consider an officer who, like Fackrell, wishes to stop
someone for investigative reasons, but does not have what
a court would view as reasonable suspicion. If the officer
believes that any evidence he discovers will be inadmissi­
ble, he is likely to think the unlawful stop not worth mak­
ing—precisely the deterrence the exclusionary rule is
meant to achieve. But when he is told of today’s decision?
Now the officer knows that the stop may well yield admis­
sible evidence: So long as the target is one of the many
millions of people in this country with an outstanding
arrest warrant, anything the officer finds in a search is
fair game for use in a criminal prosecution. The officer’s
incentive to violate the Constitution thus increases: From
here on, he sees potential advantage in stopping individu­
als without reasonable suspicion—exactly the temptation
the exclusionary rule is supposed to remove. Because the
majority thus places Fourth Amendment protections at
risk, I respectfully dissent.




—————— 

question here: What happens when an unconstitutional act in fact leads

to a warrant which then leads to evidence? 

