                 FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


LIA MARIE LINGO; V. R. S., a                No. 14-35344
minor child (age 13), through
Guardian Ad Litem, Lia Marie                 D.C. No.
Lingo; J. P. L., a minor child (age     6:12-cv-01019-MC
9), through Guardian Ad Litem,
Lia Marie Lingo,
              Plaintiffs-Appellants,         OPINION

                 v.

CITY OF SALEM, a municipality;
STEVEN ELMORE, Salem Police
Officer in his individual capacity
and as a police official for Salem;
JUSTIN CARNEY, Salem Police
Corporal in his individual
capacity and as a police official
for Salem,
             Defendants-Appellees.


      Appeal from the United States District Court
                for the District of Oregon
      Michael J. McShane, District Judge, Presiding

           Argued and Submitted April 8, 2016
                    Eugene, Oregon

                      Filed June 27, 2016
2                   LINGO V. CITY OF SALEM

    Before: Alfred T. Goodwin, Diarmuid F. O’Scannlain,
             and Edward Leavy, Circuit Judges.

                 Opinion by Judge O’Scannlain


                           SUMMARY*


                            Civil Rights

    The panel affirmed the district court’s summary judgment
in favor of police officers in an action brought under 42
U.S.C. § 1983 alleging that the officers falsely arrested
plaintiff without probable cause after unlawfully entering the
curtilage of her home to approach the back door.

    The panel held that the exclusionary rule does not apply
in § 1983 cases, and therefore police officers may rely on
unlawfully obtained evidence to defend themselves against a
constitutional tort action for false arrest. Accordingly, the
panel rejected plaintiff’s argument that the officers’ unlawful
entry into her home’s curtilage necessarily tainted the arrest
that followed. The panel held that the officers had probable
cause to arrest plaintiff for endangering the welfare of a
minor, in violation of Or. Rev. Stat. § 163.575, after smelling
marijuana emanating from her house.




  *
    This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
                  LINGO V. CITY OF SALEM                     3

                         COUNSEL

Marianne Dugan (argued), Eugene, Oregon; Brian Michaels,
Eugene, Oregon; for Plaintiffs-Appellants.

Thomas V. Cupani (argued), Assistant City Attorney, City of
Salem Legal Department, Salem, Oregon, for Defendants-
Appellees.


                         OPINION

O’SCANNLAIN, Circuit Judge:

    We must decide whether police officers may rely on
unlawfully obtained evidence to defend themselves against a
constitutional tort action for false arrest.

                               I

                              A

    On the afternoon of June 13, 2010, Lia Lingo was
engaged in an ongoing dispute with her neighbor, Suzanne
Tegroen, regarding Tegroen’s pet dog. In the course of the
day, Lingo and Tegroen each contacted the Salem, Oregon,
Police Department, and that night Officer Steven Elmore was
dispatched to Tegroen’s residence to investigate. Tegroen
told Elmore that she felt verbally abused by Lingo and felt the
need to tread lightly around her; Elmore responded that
Lingo’s conduct did not sound criminal, but that he would try
to speak with Lingo to ease tensions.
4                LINGO V. CITY OF SALEM

    Elmore walked to Lingo’s house and noticed that its rear
outside light was on. Rather than go to the home’s front door,
Elmore walked through Lingo’s carport and knocked on the
rear door located within. Stephanie Moore, a visitor,
answered the door and went to retrieve Lingo to speak with
Elmore. Elmore stated that as soon as Moore opened the
door, he smelled marijuana.

    Lingo came outside to speak with Elmore, and he asked
her about the marijuana odor. Lingo explained that she was
burning hemp-scented incense—which she admitted smells
like marijuana—but insisted that she had no actual marijuana
inside. Skeptical, Elmore asked for permission to search
Lingo’s house; Lingo refused. Later, another officer, Justin
Carney, arrived at Lingo’s house to join Elmore. Carney
stated that he also smelled marijuana coming from the house,
and again the officers asked for permission to search the
home. Lingo again refused.

    At some point during the course of Elmore’s discussion
with Lingo, Lingo’s seven-year-old child opened the back
door and peered out. Elmore asked Lingo if there were
children in her home, and she confirmed that she lived with
her two minor children. Eventually, after Lingo’s repeated
refusals to allow the officers to search her home, they placed
her under arrest for endangering the welfare of a minor, in
violation of Or. Rev. Stat. § 163.575.

    After Lingo was arrested, Elmore went into the home and
collected the two children so that they could be moved
somewhere safer. While Lingo sat in Elmore’s police car, the
children sat in the carport and eventually in the back of
Carney’s police car. At Lingo’s direction, the children were
brought to her great aunt’s house under Oregon Department
                  LINGO V. CITY OF SALEM                    5

of Human Services supervision, where they remained for
eight days.

    Following Lingo’s arrest, the police obtained a warrant to
search Lingo’s home for controlled substances, based upon an
affidavit from Elmore describing the marijuana odor he
smelled at her house. Pursuant to the warrant, Salem police
searched Lingo’s home and found several glass bongs, 1.8
grams of marijuana (including packaging), small baggies
commonly used as drug packaging materials, and a small
amount of Klonopin, which is a schedule IV prescription
drug.

                              B

    Lingo was charged by the Marion County District
Attorney with two counts of child endangerment under Or.
Rev. Stat. § 163.575. Before trial, Lingo moved to suppress
evidence the police obtained in their search of her home,
arguing that Officers Elmore and Carney violated the Fourth
Amendment by entering her carport and approaching her
home’s back door. Lingo argued that any evidence collected
by the police thereafter should be suppressed as the fruit of
that initial unlawful search. The trial court agreed and
granted Lingo’s motion to suppress. The charges against
Lingo were later dropped.

                              C

    Lingo then filed suit under 42 U.S.C. § 1983 against
Elmore, Carney, and the City of Salem, alleging that the
officers violated the First, Fourth, and Fourteenth
Amendments of the federal Constitution by falsely arresting
her without probable cause and by interfering with her (and
6                 LINGO V. CITY OF SALEM

her children’s) right to familial association by causing her
children to be removed from her home. She sought both
compensatory and punitive damages.

    The officers and the City moved for summary judgment,
and Lingo moved for partial summary judgment. In her
motion, Lingo argued that the officers violated her Fourth
Amendment rights by entering the curtilage of her home to
approach the back door. Lingo’s motion did not specify how
that violation related to her claims for false arrest or wrongful
separation from her children. Perhaps anticipating that, if she
prevailed on her motion, Lingo would then attempt to prevent
the officers from introducing evidence obtained in violation
of the Fourth Amendment to defend themselves and to justify
their decision to arrest her, the district court requested
briefing on the issue of whether the exclusionary rule had any
application in this § 1983 case.

     After receiving the supplemental briefing, the district
court agreed with Lingo that the officers had indeed violated
the Fourth Amendment by entering her home’s curtilage, but
concluded that the exclusionary rule does not apply to § 1983
claims. The court thus held that the officer’s initial Fourth
Amendment violation did not taint their ultimate arrest of
Lingo and found that, based on the marijuana they smelled at
the house, the officers indeed had probable cause to arrest
her. The court further held that the officers permissibly
relocated Lingo’s children to her aunt’s home, where they
would be away from the suspected marijuana use and where
they would not be left home alone. Finally, the court
concluded that Lingo had not adequately demonstrated
municipal liability. The court granted summary judgment for
all defendants.
                      LINGO V. CITY OF SALEM                               7

         Lingo timely appealed.

                                     D

    On appeal, Lingo challenges only the district court’s
ruling that her arrest was valid.1 Specifically, she contends
that the district court erred in concluding that the officers had
probable cause to arrest her. She argues that such conclusion
was flawed because: (1) the officers may not establish
probable cause through evidence they gathered as a result of
their illegal entry into her carport; and (2) in any event, the
undisputed facts at the scene did not support a finding of
probable cause.

         We address each argument in turn.

                                     II

    Lingo’s primary argument on appeal is that the officers’
unlawful entry into her home’s curtilage necessarily tainted
the arrest that followed. Drawing from the exclusionary
rule’s fruit-of-the-poisonous-tree doctrine, she argues that,
because the officers were not constitutionally permitted to
stand at her house’s back door,2 they did not have probable
cause to arrest her on the basis of evidence they perceived
from that unlawful vantage point.

     1
    Lingo does not challenge the district court’s conclusion that, if the
arrest was valid, so too was the officers’ decision to relocate her children,
nor does she challenge the court’s determination that Lingo failed to
demonstrate municipal liability on behalf of the City.
 2
   On appeal, the officers do not challenge the district court’s conclusion
that they violated the Fourth Amendment by entering the carport and
approaching the back door of Lingo’s home.
8                    LINGO V. CITY OF SALEM

                                    A

    We first consider Lingo’s contention that the exclusionary
rule itself should apply in a § 1983 case.3

    Of course, the government may not use evidence seized
during an unlawful search as proof against the victim at
criminal trial. See Wong Sun v. United States, 371 U.S. 471,
484 (1963). The “fruit of the poisonous tree” doctrine
extends the exclusionary rule to require suppression of other
evidence that is derived from—and is thus tainted by—the
illegal search or seizure. See id. at 487–88. These rules are
not constitutionally required, but instead are “judicially
created means of deterring illegal searches and seizures.”
Penn. Bd. of Prob. & Parole v. Scott, 524 U.S. 357, 363
(1998). And “because the [exclusionary] rule is prudential
rather than constitutionally mandated,” courts apply it “only
where its deterrence benefits outweigh its substantial social
costs.” Id. (internal quotation marks omitted). Suppression
of evidence through the rule “has always been our last resort,
not our first impulse.” Hudson v. Michigan, 547 U.S. 586,
591 (2006).

    The exclusionary rule is not “a personal constitutional
right of the party aggrieved.” United States v. Calandra,


  3
    Both the district court and the parties have focused on the issue of
whether the exclusionary rule applies in § 1983 cases. That strikes us as
a somewhat unusual question to ask here. As explained below, the
exclusionary rule is only an evidentiary remedy, which prohibits the use
of certain evidence at criminal trial. But we find no indication in the
record that Lingo ever sought to exclude evidence in this case on the basis
of such rule. Accordingly, even if we were to conclude that the
exclusionary rule does apply to this action, it is unclear whether there is
any evidentiary ruling that would be affected by that conclusion.
                  LINGO V. CITY OF SALEM                    9

414 U.S. 338, 348 (1974). Correspondingly, the rule “does
not proscribe the introduction of illegally seized evidence in
all proceedings or against all persons.” Penn. Bd. of Prob.,
524 U.S. at 363 (internal quotation marks omitted). Indeed,
the Supreme Court has “repeatedly declined to extend the
exclusionary rule to proceedings other than criminal trials.”
Id. For example, the Court has held that the rule does not
apply to grand jury proceedings, civil tax proceedings, civil
deportation proceedings, or parole revocation proceedings.
See id. at 363–64.

    Critical here, “standing to invoke the exclusionary rule
has been confined to situations where the Government seeks
to use such evidence to incriminate the victim of the unlawful
search.” Calandra, 414 U.S. at 348 (emphasis added). This
limitation makes sense: the need to deter unlawful conduct is
strongest when that conduct could result in criminal sanction
for the victim of the search. Id. Moreover, preventing the
government from using evidence in such settings takes away
an obvious incentive—the successful prosecution of
crime—that may otherwise induce the government to ignore
constitutional rights. See generally Elkins v. United States,
364 U.S. 206, 217 (1960) (purpose of exclusionary rule is to
“remov[e] the incentive to disregard” the Fourth
Amendment).

    Conversely, in a § 1983 suit, the need for deterrence is
minimal. Here, application of the exclusionary rule would
not prevent the State from using illegally obtained evidence
against someone, but instead would prevent state actors
merely from defending themselves against a claim for
monetary damages. Exclusion of evidence in this context
would not remove any preexisting incentive that the
government might have to seize evidence unlawfully. It
10                  LINGO V. CITY OF SALEM

would simply increase state actors’ financial exposure in tort
cases that happen to involve illegally seized evidence. In
effect, § 1983 plaintiffs would receive a windfall allowing
them to prevail on tort claims that might otherwise have been
defeated if critical evidence had not been suppressed. Even
if such application of the rule might in some way deter
violative conduct, that deterrence would impose an extreme
cost to law enforcement officers that is not generally
countenanced by the doctrine. See Black v. Wigington,
811 F.3d 1259, 1268 (11th Cir. 2016) (“The cost of applying
the exclusionary rule in [the § 1983] context is significant . . .
[a]nd the deterrence benefits are miniscule.”); Townes v. City
of New York, 176 F.3d 138, 148 (2d Cir. 1999) (observing
that the availability of exclusionary rule in § 1983 cases
“would vastly overdeter police officers and would result in a
wealth transfer that is peculiar, if not perverse” (internal
quotation marks omitted)); see also United States v. Leon,
468 U.S. 897, 907 (1984) (“The substantial social costs
exacted by the exclusionary rule for the vindication of Fourth
Amendment rights have long been a source of concern.”).

    For these reasons, federal courts of appeals have widely
held that the exclusionary rule does not apply in § 1983 cases.
See, e.g., Black, 811 F.3d at 1268; Townes, 176 F.3d at
145–46; Wren v. Towe, 130 F.3d 1154, 1158 (5th Cir. 1997)
(per curiam); Machado v. Weare Police Dep’t, 494 F. App’x
102, 106 (1st Cir. 2012) (per curiam). We agree, and we join
those courts now.4


     4
     Lingo mostly ignores the many cases which have rejected her
argument, and instead focuses on an inapposite doctrine: the distinction
between “intrasovereign” and “intersovereign” applications of the
exclusionary rule, highlighted by the Supreme Court in United States v.
Janis, 428 U.S. 433 (1976).
                      LINGO V. CITY OF SALEM                              11

                                     B

    Lingo’s briefs might be read to suggest that the principles
underlying the fruit-of-the-poisonous-tree doctrine mean that
information which was obtained in violation of the Fourth
Amendment may not be used as probable cause to arrest her.
In other words, Lingo suggests that perhaps the Fourth



     In Janis, the Court held that the exclusionary rule did not require
exclusion from a federal civil tax proceeding evidence that had been
unlawfully obtained by state law enforcement agents. Id. at 459–60.
Recognizing that some courts had applied the exclusionary rule in certain
civil enforcement actions, the Court distinguished those courts’ approval
of intrasovereign applications of the rule (in which the same sovereign
that was responsible for the underlying Fourth Amendment violation later
sought to use its own illegally obtained evidence) from intersovereign
applications (in which a sovereign sought to introduce evidence that had
been illegally obtained by a completely separate sovereign). Id. at
455–58. Without commenting on the validity of intrasovereign
application of the rule, the Court held that, at a minimum, the purposes of
the exclusionary rule are not served by imposing the rule in a civil
intersovereign case. Id.

     Lingo argues that Janis suggests that the exclusionary rule should be
applied in an intrasovereign § 1983 case. But this argument turns Janis
on its head. The Court’s discussion in Janis shows that the core
application of the exclusionary rule is confined to the criminal context.
See id. at 446–47. The Court addressed the intrasovereign / intersovereign
distinction only to identify yet another constraint on the rule: even in those
limited civil cases in which some courts might be inclined to apply the
rule, they may not do so in the intersovereign context. See id. at 455–58.
But the fact that the exclusionary never applies in intersovereign civil
cases says nothing for when the rule ought to apply in intrasovereign
cases.

     Accordingly, regardless whether this is an intrasovereign or an
intersovereign case, that fact would not alter our conclusion that the
exclusionary rule does not apply in a § 1983 case.
12                LINGO V. CITY OF SALEM

Amendment prohibits not only unlawful searches but also any
arrest that is justified solely on the basis of evidence procured
from such an unlawful search. We find no authority
supporting such an argument.

    As noted above, the exclusionary rule and its fruit-of-the-
poisonous-tree doctrine are “judicially created remed[ies]
designed to safeguard Fourth Amendment rights generally
through [their] deterrent effect, rather than a personal
constitutional right of the party aggrieved.” Calandra,
414 U.S. at 348. The wrong condemned by the Fourth
Amendment is the invasion of an individual’s privacy. That
wrong is already “fully accomplished by the unlawful search
or seizure itself, and the exclusionary rule is neither intended
nor able to cure” that wrong after it has occurred. Leon,
468 U.S. at 906 (internal quotation marks and citation
omitted); accord Calandra, 414 U.S. at 347. Accordingly,
“the use of fruits of a past unlawful search or seizure works
no new Fourth Amendment wrong.” Leon, 468 U.S. at 906
(internal quotation marks and alteration omitted) (emphasis
added).

    For these reasons, nothing within the fruit-of-the-
poisonous-tree doctrine suggests that an officer must ignore
facts that would give him probable cause to arrest a person
merely because those facts were procured through an
unlawful search. Indeed, as a general matter, probable cause
determinations depend on the substance of the information
known to the officer, not whether that information would be
admissible in court. See Crowe v. County of San Diego,
608 F.3d 406, 432 (9th Cir. 2010) (noting that evidence
establishing probable cause need not be admissible). And as
the Second Circuit explained in rejecting an argument similar
to Lingo’s, “[t]he evil of an unreasonable search or seizure is
                  LINGO V. CITY OF SALEM                     13

that it invades privacy, not that it uncovers crime, which is no
evil at all.” Townes, 176 F.3d at 148. The exclusionary rule
already provides a person in Lingo’s position “an enormous
benefit by reason of the illegal . . . search to which [she] was
subjected: [her] freedom, achieved by the suppression of
evidence” at criminal trial. Id. But the Supreme Court has
made clear that this suppression remedy does not mean that
the government’s use of illegally obtained evidence is itself
a constitutional concern. See, e.g., Penn. Bd. of Prob.,
524 U.S. at 362 (“We have emphasized repeatedly that the
government’s use of evidence obtained in violation of the
Fourth Amendment does not itself violate the Constitution.”).

    Once again, the federal courts of appeals that have
considered this issue appear to be in accord: “The lack of
probable cause to . . . search does not vitiate the probable
cause to arrest” on the basis of evidence found in that search.
Townes, 176 F.3d at 149; see also Black, 811 F.3d at 1268
(“[O]fficers can rely on [illegally obtained evidence] to prove
that the arrest warrants were supported by probable cause.”);
Hector v. Watt, 235 F.3d 154, 157 (3d Cir. 2001) (“Victims
of unreasonable searches or seizures may recover damages
directly related to the invasion of their privacy . . . but such
victims cannot be compensated for injuries that result from
the discovery of incriminating evidence and consequent
criminal prosecution.” (internal quotation marks omitted));
Vigeant v. United States, 245 F. App’x 23, 24–25 (1st Cir.
2007) (per curiam) (agents executing an invalid search
warrant had probable cause to arrest homeowner after
discovering firearms in the house). We again agree, and we
join those courts in rejecting Lingo’s suggestion that probable
cause to arrest may be supported only by information that was
obtained in accordance with the Fourth Amendment.
14                LINGO V. CITY OF SALEM

                              III

    Finally, Lingo argues that even if the officers are
permitted to justify their decision to arrest her through
evidence they obtained unlawfully, there are genuine issues
of fact regarding whether the circumstances in this case gave
the officers probable cause to arrest her. “Probable cause for
a warrantless arrest arises when the facts and circumstances
within the officer’s knowledge are sufficient to warrant a
prudent person to believe that the suspect has committed an
offense.” Crowe, 608 F.3d at 432 (internal quotation marks
and ellipsis omitted). The facts must be such that a prudent
person would conclude that there was a “fair probability” the
individual committed the crime. Id. (internal quotation marks
omitted).

    Lingo was arrested and charged with violation of Or. Rev.
Stat. § 163.575, which, among other things, makes it a crime
to “[p]ermit[] a person under 18 years of age to enter or
remain in a place where unlawful activity involving
controlled substances is maintained or conducted.” Id.
§ 163.575(1)(b). Marijuana is a Schedule II controlled
substance in Oregon, Or. Admin. R. 855-080-0022 (2016)
(Schedule of Controlled Substances), and at the time of arrest,
it was unlawful for any person in Oregon “knowingly or
intentionally to possess marijuana,” Or. Rev. Stat. § 475.864,
unless the person held a valid medical marijuana card, see
Emerald Steel Fabricators, Inc. v. Bureau of Labor & Indus.,
230 P.3d 518, 519–20 (Or. 2010).

   There is little question that the officers had probable
cause to arrest Lingo for this offense. Both officers at the
scene stated that they smelled a strong marijuana odor
emanating from Lingo’s house. Both officers were trained to
                 LINGO V. CITY OF SALEM                    15

detect such odors, and Lingo herself admitted the presence of
such an odor. Prior to the arrest, Elmore ran a records check
on Lingo and confirmed that she did not have a medical
marijuana card and that the house was not a registered
medical marijuana grow site. In other words, the officers
knew it was unlawful for Lingo knowingly to possess
marijuana, and, in turn, that it was a crime for her to allow
minors to remain in a place in which she did. Once the
officers saw one of Lingo’s children—and once Lingo herself
told the officers that she had two minor children in the
house—the underlying facts needed to sustain a violation of
section 163.575 were complete. In short, the combination of
the marijuana odor, the undisputed presence of Lingo’s
children in the house, and the fact that Lingo did not have
medical marijuana privileges gave the officers probable cause
to believe that Lingo had committed a crime. See, e.g.,
United States v. Kerr, 876 F.2d 1440, 1445 (9th Cir. 1989)
(“[T]he presence of the odor of contraband may itself be
sufficient to establish probable cause.”); United States v.
Barron, 472 F.2d 1215, 1217 (9th Cir. 1973) (per curiam)
(“[T]he fact that an agent familiar with the odor of
marijuana[] smelled such an odor emanating from the
automobile . . . alone was sufficient to constitute probable
cause . . . .”); State v. Derrah, 84 P.3d 1084, 1087 (Or. Ct.
App. 2004) (“The scent of marijuana, emanating from a
residence, without more, is sufficient to support a conclusion
that marijuana will likely be found inside that residence.”).

     Lingo does not dispute the well-founded conclusion
that—if the officers could smell marijuana—they had
probable cause to arrest her. Instead, she makes a passing
attempt to cast doubt on the veracity of the officers’
assertions that they actually smelled the drug, by noting how
little marijuana was later found in her home. But Lingo’s
16                LINGO V. CITY OF SALEM

skepticism flies in the face of her own admission that she told
the officers they smelled hemp incense, which she said
does—and is intended to—smell like marijuana. In other
words, it is undisputed that there was a marijuana-like odor,
even if Lingo insists that the officers could not rule out the
possibility that the odor came from something other than
marijuana itself.

    It is decidedly not the officers’ burden to “rule out the
possibility of innocent behavior” in order to establish
probable cause. Ramirez v. City of Buena Park, 560 F.3d
1012, 1024 (9th Cir. 2009) (internal quotation marks
omitted). Indeed, “[r]arely will a suspect fail to proffer an
innocent explanation for his suspicious behavior.” Id. Thus,
the mere fact that Lingo suggested a potential lawful source
of the marijuana-like odor does nothing to contradict the
officers’ statements that such an odor existed. In short, Lingo
gives no reason to doubt that the officers indeed smelled what
they suspected to be marijuana; as explained above, such odor
gave the officers probable cause to arrest Lingo under Oregon
law.

                              IV

   For the foregoing reasons, the judgment of the district
court is AFFIRMED.
