FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


MIGUEL ANGEL REYNAGA                 No. 19-35513
HERNANDEZ,
               Plaintiff-Appellee,      D.C. No.
                                     1:18-cv-00040-
                v.                        SPW

DERREK SKINNER, in his individual
capacity,
             Defendant-Appellant,

               and

PEDRO HERNANDEZ, in his individual
capacity,
                       Defendant.
2              REYNAGA HERNANDEZ V. SKINNER


 MIGUEL ANGEL REYNAGA                                No. 19-35514
 HERNANDEZ,
                Plaintiff-Appellee,                    D.C. No.
                                                    1:18-cv-00040-
                      v.                                 SPW

 PEDRO HERNANDEZ, in his individual
 capacity,                                             OPINION
             Defendant-Appellant,

                     and

 DERREK SKINNER, in his individual
 capacity,
                          Defendant.

         Appeal from the United States District Court
                 for the District of Montana
          Susan P. Watters, District Judge, Presiding

             Argued and Submitted March 2, 2020
                      Portland, Oregon

                      Filed August 10, 2020

    Before: Roger L. Wollman, * Ferdinand F. Fernandez,
            and Richard A. Paez, Circuit Judges.

                      Opinion by Judge Paez



    *
      The Honorable Roger L. Wollman, United States Circuit Judge for
the U.S. Court of Appeals for the Eighth Circuit, sitting by designation.
              REYNAGA HERNANDEZ V. SKINNER                           3

                          SUMMARY **


                           Civil Rights

    The panel affirmed the district court’s order, on
summary judgment, denying qualified immunity to
defendants in an action brought pursuant to 42 U.S.C. § 1983
alleging that plaintiff’s Fourth Amendment rights were
violated when he was stopped and arrested without
reasonable suspicion or probable cause.

    Plaintiff was arrested after a witness in a courtroom
testified that plaintiff, who had accompanied his wife to the
hearing to serve as a witness, was not a legal citizen. On the
basis of this statement, defendant Pedro Hernandez, the
Justice of the Peace presiding over the hearing, requested
that plaintiff be “picked up” by the local Sheriff’s Office.
Defendant, Deputy Sheriff Derrek Skinner, subsequently
detained plaintiff to question him regarding his immigration
status, placed plaintiff in handcuffs, searched his person, and
escorted him to a patrol car outside the courthouse.

    The panel first noted that, unlike illegal entry into the
United States—which is a crime under 8 U.S.C. § 1325—
illegal presence is not a crime. See Martinez-Medina,

, 1036 (9th Cir. 2011). Therefore, “because
mere unauthorized presence is not a criminal matter,
suspicion of unauthorized presence alone does not give rise
to an inference that criminal activity is afoot.” Melendres v.
Arpaio, 

, 1001 (9th Cir. 2012). Because
Melendres and Martinez-Medina controlled and defendant

    **
       This summary constitutes no part of the opinion of the court. It
has been prepared by court staff for the convenience of the reader.
4            REYNAGA HERNANDEZ V. SKINNER

Skinner failed to demonstrate that he had a particularized
and objective basis for believing criminal activity was afoot,
the panel affirmed the district court’s holding that Skinner
violated the Fourth Amendment when he seized plaintiff by
Terry-stopping and then arresting him without reasonable
suspicion or probable cause, respectively.

    The panel further held that under either the proximate or
the but-for standard of causation, defendant Hernandez was
an integral participant in the violation of plaintiff’s
constitutional rights. The panel held that plaintiff’s right to
be free from unlawful stops in this circumstance had been
established since at least 2012, by which time both
Melendres and Martinez-Medina were law of the circuit.


                         COUNSEL

Levi A. Robison (argued), Melissa A. Williams, and Mark
A. English, Deputy Yellowstone County Attorneys, Billings,
Montana, for Defendants-Appellants.

Matt Adams (argued), Leila Kang, Aaron Korthuis, and
Anne Recinos, Northwest Immigrant Rights Project, Seattle,
Washington; Shahid Haque, Border Crossing Law Firm
P.C., Helena, Montana; for Plaintiff-Appellee.
            REYNAGA HERNANDEZ V. SKINNER                  5

                        OPINION

PAEZ, Circuit Judge:

    In late 2017, a witness in a courtroom in Billings,
Montana, testified that one of the other witnesses, Miguel
Reynaga Hernandez (“Reynaga”), was “not a legal citizen.”
On the basis of this statement, the Justice of the Peace
presiding over the hearing spoke with the local Sheriff’s
Office and asked that Reynaga be “picked up.”

    Deputy Sheriff Derrek Skinner responded to the call.
Outside the courtroom, Skinner asked Reynaga for
identification and questioned him regarding his immigration
status in the United States. Reynaga produced an expired
Mexican consular identification card but was unable to
provide detailed information regarding his immigration
status because he does not speak English fluently. Skinner
then placed Reynaga in handcuffs, searched his person, and
escorted him to a patrol car outside the courthouse. With
Reynaga waiting in the back of the patrol car, Skinner ran a
warrants check and, after Reynaga’s record came back clean,
asked Immigrations and Custom Enforcement (“ICE”) if the
agency had any interest in Reynaga. Reynaga was ultimately
taken to an ICE facility and remained in custody for three
months.

   Upon his release, Reynaga sued Skinner and Pedro
Hernandez, the presiding Justice of the Peace
(“Hernandez”), under 42 U.S.C. § 1983 for violating his
Fourth Amendment rights. On cross-motions for summary
judgment, the district court denied each defendant qualified
immunity and held that Reynaga’s Fourth Amendment rights
had been violated. Skinner and Hernandez interlocutorily
appeal the court’s denial of qualified immunity. We affirm.
6           REYNAGA HERNANDEZ V. SKINNER

                             I.

                             A.

    The testimony precipitating Reynaga’s arrest occurred
during a hearing on a civil order of protection. Jane Reynaga
Hernandez (“Jane”) had filed a request for a protection order
against Rachel Elizondo (“Rachel”) in the Yellowstone
County Justice Court in Billings, Montana. Jane’s husband,
plaintiff-appellee Reynaga, accompanied her to the hearing
to serve as a witness.

    On the morning of the hearing, Hernandez asked
Reynaga and another witness to wait outside the courtroom
before they testified. Rachel then took the stand. During her
testimony, she stated that Reynaga was “not a legal citizen.”
She made a similar statement about the other witness waiting
with Reynaga. She did not testify that either witness had
unlawfully entered the United States nor describe their
manner of entry.

     At the conclusion of Rachel’s testimony, Hernandez
responded, “What I’m hearing here are allegations about
illegal immigrant [sic].” He directed his staff, “call me a
deputy. I have two illegals sitting outside. I want them
picked up.” Once his staff connected him to the Sheriff’s
Office, Hernandez requested the Office to “send me a couple
of deputies. I have two illegal immigrants out in the hallway
. . . they are in the hall. Get them here as quickly as
possible.”

   After speaking on the phone with the Sheriff’s Office,
Hernandez denied Jane’s request for an order of protection
and told both Jane and Rachel that he would hold them in
contempt of court and arrest them if they tried to leave the
courtroom. He wanted to prevent Jane and Rachel from
            REYNAGA HERNANDEZ V. SKINNER                  7

leaving because he “believed that they might tell [Reynaga
and the other witness] that a deputy was on the way to
investigate their immigration status and they would flee.”

    The Sheriff’s Office relayed Hernandez’s request to
Skinner, a deputy sheriff at the time. The Office informed
Skinner that Hernandez had called regarding “two illegal
immigrants outside his courtroom that he wants picked up.”
Skinner was dispatched to the courthouse. When he entered
the courtroom, Hernandez told him, “the information I have
from them two under oath, they are illegal aliens.” Skinner
replied he would “take care of it.” Hernandez then told him,
“see what happens. If you guys take them, let me know
please,” and advised that Skinner “may have to call
immigration . . . their testimony from the witness stand is
they are illegal.”

    Skinner stepped into the hallway outside the courtroom
and asked Reynaga for identification and his immigration
status. Reynaga handed Skinner an expired Mexican
consulate identification card but—because Reynaga does
not speak English fluently—was unable to provide detailed
information regarding his immigration status.           His
identification card from the Mexican consulate does not
indicate his immigration status, either in Mexico or in the
United States.

    Reynaga then tried to enter the courtroom to reach his
wife, but Skinner blocked his path and handcuffed him.
Skinner searched Reynaga’s person and, after failing to find
anything, removed Reynaga from the courthouse and placed
him into a patrol car outside. While Reynaga sat handcuffed
in the patrol car, Skinner ran a warrants check. There were
no outstanding warrants for Reynaga. Skinner then asked
the Yellowstone County Dispatch if ICE “wanted him.” An
ICE agent returned Skinner’s call and asked Skinner to
8           REYNAGA HERNANDEZ V. SKINNER

transport Reynaga to the Yellowstone County Detention
Facility.

    Reynaga was placed in ICE custody. After three months
of being transported between various detention facilities, the
Department of Homeland Security dismissed the deportation
proceeding it had commenced against Reynaga.

                             B.

    After being released from detention, Reynaga filed suit
under 42 U.S.C. § 1983 in the District Court of the District
of Montana against Hernandez and Skinner, alleging that
they violated his constitutional rights under color of state
law. See Hernandez v. Skinner, 

, 1082
(D. Mont. 2019). He seeks compensatory and punitive
damages and a declaratory judgment that the two violated
his Fourth Amendment rights.

for summary judgment on the
section 1983 claims, punitive damages, and request for
declaratory relief.

concluded that the
material facts underlying Reynaga’s Fourth Amendment
claims and Hernandez’s and Skinner’s affirmative defense
that they were entitled to qualified immunity were
undisputed.

The court then proceeded to the
merits of those claims, holding that Skinner had violated
Reynaga’s constitutional rights because he lacked either
reasonable suspicion or probable cause that Reynaga was
involved in criminal activity

and Hernandez
violated Reynaga’s Fourth Amendment rights because he
was an “integral participant” in Skinner’s unlawful actions

   Relying on our caselaw holding that “illegal presence . . .
does not, without more, provide probable cause of the
            REYNAGA HERNANDEZ V. SKINNER                    9

criminal violation of illegal entry,”

(citing
Martinez-Medina v. Holder, 

, 1036 (9th Cir.
2011)), the court held that Reynaga’s Fourth Amendment
rights were clearly established at the time of the alleged
offense, and denied both Hernandez and Skinner qualified
immunity

–87. The court did not address
Reynaga’s request for punitive damages because it found
there were outstanding genuine issues of fact regarding
Hernandez’s and Skinner’s intent.

    Hernandez and Skinner interlocutorily appeal the court’s
denial of qualified immunity. They argue that the district
court erred by holding that Reynaga’s Fourth Amendment
rights were violated by Hernandez and Skinner, Hernandez
was an integral participant in Reynaga’s unlawful seizure,
and Reynaga’s rights were clearly established at the time of
the alleged offenses.

                             II.

    We have jurisdiction over Hernandez’s and Skinner’s
appeals under 28 U.S.C. § 1291. An order denying a motion
for summary judgment is not typically a “final decision”
within the meaning of section 1291, but “that general rule
does not apply when the summary judgment motion is based
on a claim of qualified immunity.” Plumhoff v. Rickard,

, 771 (2014). “[P]retrial orders denying
qualified immunity generally fall within the collateral order
doctrine.”

    Jurisdiction in such cases is limited to “questions of law
and does not extend to claims in which the determination of
qualified immunity depends on disputed issues of material
fact.” Jeffers v. Gomez, 

, 903 (9th Cir. 2001).
We review de novo any questions of law underlying the
denial of qualified immunity. Wilkins v. City of Oakland,
10             REYNAGA HERNANDEZ V. SKINNER

, 954 (9th Cir. 2003). Where disputed facts do
exist, we determine whether the denial of qualified immunity
was appropriate by evaluating the facts in the light most
favorable to the non-moving party. 

.

                                   III.

    Hernandez and Skinner present a single question on
appeal: whether the district court erred in denying them
qualified immunity. Reynaga brought his claims under
section 1983, which confers a tort remedy upon individuals
“whose constitutional rights have been violated by state
officials acting ‘under color of’ law.” Whalen v. McMullen,

, 1145 (9th Cir. 2018) (quoting 42 U.S.C.
§ 1983). Public officials—including police officers and
judges—are qualifiedly immune from suit 1 under section
1983 except where the violation should have been obvious

     1
      Judges are also entitled to absolute immunity from damages suits.
See Supreme Court of Virginia v. Consumers Union, 

, 734–
35 (1980). Absolute judicial immunity “insulates judges from charges
of erroneous acts or irregular action.” Curry v. Castillo (In re Castillo),

, 947 (9th Cir. 2002). A judge is not immune for
“nonjudicial actions, i.e., actions not taken in the judge’s judicial
capacity,” or for “actions, though judicial in nature, taken in the complete
absence of all jurisdiction.” Harvey v. Waldron, 

, 1012
(9th Cir. 2000) (internal quotation marks omitted), overruled in part on
other grounds by Wallace v. Kato, 

, 393–94 (2007).

     However, neither here nor in the district court did Hernandez argue
that he is entitled to judicial immunity. He has therefore waived any
such defense. See, e.g., Siegert v. Gilley, 

, 231 (1991)
(“Qualified immunity is a defense that must be pleaded by a defendant
official.”); Sablan v. Dep’t of Fin., 

, 1321 (9th Cir. 1988)
(“On appeal, the various government officials who are named in their
individual capacity do not raise any claim of absolute or qualified
immunity. We will therefore treat any potential claims of official
immunity as waived.”).
             REYNAGA HERNANDEZ V. SKINNER                   11

to the official because the right at issue was “clearly
established.”

Forsyth, 

,
525 (1985)).

    To determine whether an official is entitled to qualified
immunity, we evaluate whether (1) the alleged facts
constitute a violation of a constitutional right, and (2) the
constitutional right was clearly established at the time of the
violation. Mitchell v. Washington, 

, 443 (9th
Cir. 2016). We address each factor in turn.

                              A.

    We first consider whether the district court erred in
holding, on the basis of the nondisputed material facts, that
Hernandez and Skinner violated Reynaga’s constitutional
rights. The Fourth Amendment to the United States
Constitution protects individuals against “unreasonable
searches and seizures.” U.S. Const. amend. IV. There are
two categories of police seizures under the Fourth
Amendment: Terry stops and full-scale arrests. See Allen v.
City of Portland, 

, 235 (9th Cir. 1995).

    Under Terry v. Ohio, 

(1968), police officers
may conduct a brief, investigative stop of an individual when
they have reasonable suspicion that the “person apprehended
is committing or has committed a criminal offense.” Arizona
v. Johnson, 

, 326 (2009). We examine the
“totality of the circumstances” to determine whether a
detaining officer has a “particularized and objective basis”
for suspecting criminal wrongdoing. United States v. Arvizu,

, 273 (2002) (internal quotation marks omitted).
An officer cannot rely only upon generalizations that “would
cast suspicion on large segments of the lawabiding
population.” United States v. Manzo-Jurado, 

,
935 (9th Cir. 2006). “Seemingly innocuous behavior,”
12          REYNAGA HERNANDEZ V. SKINNER

unless combined with other circumstances indicating
criminality, does not justify a Terry stop.

stop motivated by reasonable suspicion,
the officer may ask investigatory questions, but the “scope
of the detention must be carefully tailored to its underlying
justification.” Florida v. Royer, 

, 500 (1983).
A stop for the purposes of investigating unlawful
immigration “usually consume[s] less than a minute and
involve[s] a brief question or two.” Dunaway v. New York,

, 210–11 (1979) (internal quotation marks
omitted).

    The second category of police seizures are arrests. An
arrest must be supported by probable cause to believe that
the person being arrested has committed a crime. See 

(citing Henry v. United States, 

,
102 (1959)). Probable cause is more difficult to establish
than reasonable suspicion, and is determined at the time the
arrest is made. 

–74; 

. It must be based on “reasonably trustworthy
information sufficient to warrant a prudent person in
believing that the accused had committed or was committing
an offense.” 

(internal quotation marks
omitted). Like reasonable suspicion, it can “only exist in
relation to criminal conduct.”

Skinner’s and Hernandez’s
actions in turn.

Defendant Skinner

    Skinner concedes that he conducted a Terry stop the
moment he questioned Reynaga regarding his immigration
status and conducted an arrest after placing Reynaga in the
police vehicle. At issue, then, is only whether Skinner had
               REYNAGA HERNANDEZ V. SKINNER                          13

reasonable suspicion or probable cause to conduct the stop
and arrest, respectively.

    1. Terry stop

    Skinner conducted a Terry stop when he confronted
Reynaga outside the courtroom, asked him questions
regarding his immigration status, and requested
identification. 2 The parties agree that at the time Skinner
conducted the stop, the only relevant information available
to Skinner was Hernandez’s statement that he had heard
sworn testimony that Reynaga was “not a legal citizen.”

    Unlike illegal entry into the United States—which is a
crime under 8 U.S.C. § 1325—illegal presence is not a
crime. See 

(stating that
there is no “federal criminal statute making unlawful
presence in the United States, alone, a federal crime[.]”). A
migrant who is illegally present in the United States may
have committed a civil violation—by overstaying a visa,
changing her student status, or acquiring prohibited
employment—or a criminal violation, by entering the

    2
      “[N]ot every encounter between a police officer” and an individual
“is an intrusion requiring objective justification.” United States v.
Mendenhall, 

, 553 (1980). A seizure under the Fourth
Amendment occurs only when a reasonable person would not feel free
to leave or decline the officer’s requests. See Brendlin v. California,

, 255 (2007). But Skinner does not dispute that he seized
Reynaga when he confronted him, either here or in the district court. See
Op. Br. 21 (“Skinner did not violate [Reynaga’s] right against
unreasonable searches and seizures when he detained . . . [Reynaga].
Skinner had a reasonable suspicion that [Reynaga] might have
committed a crime as indicated by his presence in the United States.”);

(“Deputy Skinner does not dispute
he detained, or Terry stopped, [Reynaga] the moment he began
questioning him.”).
14           REYNAGA HERNANDEZ V. SKINNER

country illegally. See Gonzales v. City of Peoria, 

, 476–77 (9th Cir. 1983), overruled on other grounds by
Hodgers-Durgin v. de la Vina, 

(9th Cir. 1999)
(en banc); Arizona v. United States, 

, 407
(2012) (“As a general rule, it is not a crime for a removable
alien to remain present in the United States.”). Therefore,
“because mere unauthorized presence is not a criminal
matter, suspicion of unauthorized presence alone does not
give rise to an inference that criminal activity is ‘afoot.’”
Melendres v. Arpaio, 

, 1001 (9th Cir. 2012)
(quoting 

).

    We held in Melendres that “detaining individuals based
solely on reasonable suspicion or knowledge that a person
was unlawfully present in the United States” is not
sufficiently “premised on criminality” to justify a stop under

–01. The single statement conveyed
by Hernandez regarding Reynaga’s unlawful status, then,
was not a sufficiently “particularized and objective basis” for
Skinner to believe that Reynaga was “engaged in, or [] about
to engage in, criminal activity[.]” United States v. Sandoval,

, 1080 (9th Cir. 2004) (emphasis added); see
also 

–74. Hernandez did not describe
Reynaga’s manner of entry nor provide additional
information suggestive of criminal conduct.

    In Melendres, Latino motorists brought a putative class
action under section 1983 against a county sheriff’s office, a
sheriff, and other individuals, alleging that the defendants
unlawfully engaged in a policy or practice of racially
profiling Latino individuals in connection with vehicle
stops. 

–95. In reviewing the preliminary
injunction entered by the district court, we concluded that
the plaintiff-class was likely to succeed on the merits of its
claims because the class members’ Fourth Amendment
             REYNAGA HERNANDEZ V. SKINNER                   15

rights had been violated.

–02. 
Although “illegal
presence may be some indication of illegal entry, unlawful
presence need not result from illegal entry. For example, an
individual may have entered the country lawfully, but
overstayed his or her visa.”
 Id. at 1001 
(internal quotation
marks and citation omitted). Nothing in our previous
caselaw, we explained, “suggests that presence alone is
sufficient to justify a stop by the . . . officers who are not
empowered to enforce civil immigration violations.”
 Id.

    Melendres expanded upon 
a then-recent case, Martinez-
Medina v. Holder, 
673 F.3d 1029 
(9th Cir. 2011). In
Martinez-Medina, two immigrants admitted to a deputy
sheriff that they were unlawfully present in the country.
 Id.
at 1031. 
The officer approached the pair at a gas station and
asked about their travel plans and whether they had
identification and green cards.
 Id. One of the 
two
immigrants spoke to the officer with help from his son, who
acted as a translator.
 Id. Interpreting the officer’s 
request
for green cards as a question about their immigration status
in the United States, the two responded that they did not have
green cards.
 Id. The officer then 
warned them they could
not leave until “Immigration” arrived.
 Id. at 1031–32.
    At that point, we explained, the officer had seized the
two within the meaning of the Fourth Amendment, only on
suspicion that they were unlawfully present in the country.

Id. at 1034. 
We held that the officer’s actions did not
egregiously violate the immigrants’ constitutional rights,
because our caselaw regarding whether law enforcement
officers may draw inferences about criminality from an
individual’s immigration status was less than clear at the
time.
 

–37. 
But we clarified that “an alien who is
illegally present in the United States . . . [commits] only a
civil violation,” and “admission of illegal presence . . . does
16           REYNAGA HERNANDEZ V. SKINNER

not, without more, provide probable cause of the criminal
violation of illegal entry.”
 Id. at 1036 
(internal quotation
marks omitted) (alterations in original). This “always [was],
and remain[ed], the law of the circuit, binding on law
enforcement officers.”
 Id.

    Hernandez and Skinner 
concede at various points in their
appellate briefs that Melendres forecloses their argument
that illegal presence alone may establish reasonable
suspicion. They argue only that (1) we “should overrule the
holding in Melendres that illegal presence in the United
States does not create a reasonable suspicion that the person
illegally entered the United States,” Op. Br. 30, and (2) they
had “little experience with the enforcement of immigration
law,” so it was “reasonable for [them] to believe the general
standard for investigatory stops would apply” to Reynaga,
Op. Br. 42.

    First, we cannot overrule Melendres.             Absent
intervening, controlling authority, a three-judge panel may
not overrule a prior decision of this court. See Miller v.
Gammie, 
335 F.3d 889
, 899–900 (9th Cir. 2003) (en banc).
Skinner and Hernandez do not point to a Supreme Court case
or federal law calling Melendres into question.

    Second, the standard for evaluating whether a Fourth
Amendment violation occurred is objective, not subjective;
Skinner’s and Hernandez’s own experiences with
immigration matters are irrelevant. Ashcroft v. al-Kidd,
563 U.S. 731
, 740 (2011) (“Efficient and evenhanded
application of the law demands that we look to whether the
arrest is objectively justified, rather than to the motive of the
arresting officer.” (footnote omitted)).

   Because Melendres and Martinez-Medina control and
Skinner fails to demonstrate that he had a particularized and
              REYNAGA HERNANDEZ V. SKINNER                        17

objective basis for believing “criminal activity [was] afoot,”
Terry, 392 U.S. at 30
, we hold the district court did not err
in concluding that Skinner lacked reasonable suspicion to
stop Reynaga.

    2. Arrest

    Skinner concedes he did not have probable cause to
arrest Reynaga until after he contacted ICE. He instead
argues that he arrested Reynaga only after he had spoken
with the ICE agent. 3 We evaluate, then, whether Reynaga
was arrested within the meaning of the Fourth Amendment
prior to Skinner’s phone call with the ICE agent.

    To determine whether a Terry stop has escalated into a
full-blown arrest, we evaluate the severity of the intrusion,
the aggressiveness of the officer’s actions, and the
reasonableness of the officer’s methods under the
circumstances. Washington v. Lambert, 
98 F.3d 1181
,
1188–89 (9th Cir. 1996). There is no bright-line rule. The
use of “especially intrusive means” of effecting Terry stops
has been held permissible in certain circumstances,
including:

        1) where the suspect is uncooperative or takes
        action at the scene that raises a reasonable
        possibility of danger or flight; 2) where the
        police have information that the suspect is
        currently armed; 3) where the stop closely
        follows a violent crime; and 4) where the

    3
       It is unclear what Skinner learned about Reynaga’s immigration
status from ICE. The record indicates that Skinner “asked dispatch to
see” if ICE “wanted” Reynaga. An ICE agent then called Skinner and
asked him to transport Reynaga to the Yellowstone County Detention
Facility.
18          REYNAGA HERNANDEZ V. SKINNER

       police have information that a crime that may
       involve violence is about to occur.


Id. at 1189 
(footnotes omitted). Handcuffing as a means of
detaining an individual does not automatically escalate a
stop into an arrest, but it “substantially aggravates the
intrusiveness of an otherwise routine investigatory detention
and is not part of a typical Terry stop.” United States v.
Bautista, 
684 F.2d 1286
, 1289 (9th Cir. 1982); see also Allen
v. City of Los Angeles, 
66 F.3d 1052
, 1057 (9th Cir. 1995).

    At the time Skinner handcuffed Reynaga, brought him
outside, and placed him into the patrol vehicle, there was no
evidence suggesting that Reynaga was armed,
uncooperative, dangerous, or a flight risk. Reynaga, by all
accounts, fully complied with Skinner’s requests, and
Skinner’s actions substantially aggravated the intrusiveness
of his questioning. A reasonable individual in Reynaga’s
position would not have felt free to leave after being blocked
from entering the courtroom, handcuffed, taken outside, and
placed in Skinner’s patrol vehicle. See United States v. Del
Vizo, 
918 F.2d 821
, 824–26 (9th Cir. 1990); see also Benitez-
Mendez v. I.N.S., 
752 F.2d 1309
, 1311 (9th Cir. 1983)
(holding that an individual detained in a Border Patrol
vehicle while officers checked his immigration papers was
seized within the meaning of the Fourth Amendment). We
affirm the district court’s holding that Reynaga was arrested
by the time he was placed in the back of the patrol vehicle,
prior to Skinner’s call to ICE.

    As discussed, Skinner concedes that he did not have
probable cause to arrest Reynaga before speaking with the
ICE agent, making the arrest unlawful. Construing the facts
in the light most favorable to Reynaga, we affirm the district
court’s holding that Skinner violated the Fourth Amendment
             REYNAGA HERNANDEZ V. SKINNER                     19

when he seized Reynaga by Terry-stopping and arresting
him without reasonable suspicion or probable cause,
respectively.

Defendant Hernandez

    The district court concluded that Hernandez seized
Reynaga because he was an “integral participant” in
Skinner’s unlawful actions. As a predicate to section 1983
liability, each public official must integrally participate in
the unlawful seizures of Reynaga. See Boyd v. Benton
County, 
374 F.3d 773
, 780 (9th Cir. 2004).

    We have yet to define the minimum level of involvement
for liability under the integral-participant doctrine. The
official’s individual actions need not “themselves rise to the
level of a constitutional violation,”
 id., but the official 
must
be more than a “mere bystander[],” Bravo v. City of Santa
Maria, 
665 F.3d 1076
, 1090 (9th Cir. 2011). In Blankenhorn
v. City of Orange, 
485 F.3d 463 
(9th Cir. 2007), for example,
we held that an officer whose actions were “instrumental” in
effectuating a constitutional violation was an integral
participant.
 Id. at 481 
n.12. The officer handcuffed the
suspect, which then allowed another officer to place hobble
restraints on him.
 Id. at 480. 
We held that the use of hobble
restraints was an excessive use of force and not justified as a
matter of law, and that the handcuffing officer integrally
participated in the unlawful use of those restraints.
 Id. at 469
& n.3, 478–80; see also Keates v. Koile, 
883 F.3d 1228
, 1242
(9th Cir. 2018) (holding that a complaint adequately alleged
defendants were integral participants in a violation of the
right to familial association because defendants “were aware
of [the child’s] situation . . . and participated in a meaningful
way in a collective decision” to remove the child from her
mother’s custody).
20           REYNAGA HERNANDEZ V. SKINNER

    Helpful to this analysis are the standards of causation
under tort law. Constitutional violations under section 1983
are a species of tort liability. See Carey v. Piphus, 
435 U.S.
247
, 253–55 (1978); City of Monterey v. Del Monte Dunes
at Monterey, Ltd., 
526 U.S. 687
, 727 (1999) (Scalia, J.,
concurring in part). Tort law measures causation by
reference to two standards: proximate and but-for cause.
“Proximate cause is often explicated in terms of
foreseeability or the scope of the risk created by the predicate
conduct.” Paroline v. United States, 
572 U.S. 434
, 445
(2014). It precludes liability only “where the casual link
between conduct and result is so attenuated that the
consequence is more aptly described as mere fortuity.”
 Id.
But-for causation, instead, 
exists where the alleged injury or
result would not have occurred “but for” that conduct. White
v. Roper, 
901 F.2d 1501
, 1505–06 (9th Cir. 1990).

    We have not clarified whether we import both proximate
cause and but-for cause into our integral-participant
doctrine. Blankenhorn suggests that we require only but-for
cause, as there was no indication that the officer who was an
integral participant knew that the other officer would use
hobble restraints. 
See 485 F.3d at 481 
n.12. The officer who
used the hobble restraints stated in a declaration that the
handcuffing officer’s help was “instrumental in the officers’
gaining control” of the suspect, which “culminated in [the]
application of hobble restraints.”
 Id. In other words, 
but for
the use of handcuffs, the officer would not have been able to
apply the hobble restraints. We did not address the
foreseeability of the use of restraints or the scope of risk
created by using handcuffs.

   Under either standard of causation, however, Hernandez
was an integral participant in the violation of Reynaga’s
constitutional rights. The but-for standard is easily met:
            REYNAGA HERNANDEZ V. SKINNER                   21

Skinner would not have been present at the courthouse or
questioned Reynaga but-for Hernandez’s phone call. And
Reynaga’s unlawful stop and arrest were reasonably
foreseeable consequences—or, at the very least, within the
scope of risk—of Hernandez’s orders. Indeed, once
Hernandez learned from the witness’s testimony that
Reynaga was unlawfully present in the United States, he
ordered his staff to contact the sheriff’s office because he
“want[ed] [the witnesses] picked up.” Hernandez did not, as
he now argues, “request[] an investigation.” Op. Br. 23.
After ordering that he wanted Reynaga “picked up,” he then
directed Reynaga’s wife to remain in the courtroom so that
she could not warn Reynaga of Skinner’s impending arrival.
Skinner told Hernandez he would “take care of it,” and
Hernandez offered no clarification that he preferred Skinner
conduct an investigation or mere inquiry. Reynaga’s
detention was a reasonably foreseeable consequence—
indeed, perhaps the only reasonable interpretation—of
Hernandez’s order that Reynaga be “picked up.”

    Hernandez argues that “[t]he integral participant
doctrine is not based on logic,” and, if we conclude
Hernandez was an integral participant, we should “overturn
the doctrine[.]” Reply Br. 13. As a three-judge panel, we
cannot simply overrule circuit precedent. 
Miller, 335 F.3d
at 899
–900. Hernandez does not point to any federal law or
Supreme Court case that effectively overrules the doctrine.
We hold that the district court did not err in concluding that
Hernandez was an integral participant in Reynaga’s
unlawful stop and detention.

                           *    *   *

    We affirm the district court’s conclusion that, viewing
the facts in the light most favorable to Reynaga, Skinner
violated the Fourth Amendment by detaining and arresting
22           REYNAGA HERNANDEZ V. SKINNER

Reynaga without reasonable suspicion or probable cause,
respectively, and that Hernandez was an integral participant
in that unlawful conduct.

                             B.

    The second prong in the qualified-immunity analysis is
whether the constitutional right in question was clearly
established at the time of the alleged violation. Saucier v.
Katz, 
533 U.S. 194
, 201 (1994). The “clearly established
law” that has been allegedly violated “should not be defined
at a high level of generality”; it must be “particularized” to
the facts of the case. White v. Pauly, 
137 S. Ct. 548
, 552
(2017) (internal quotation marks omitted). “[T]he contours
of the right must be sufficiently clear that a reasonable
official would understand that what he is doing violates that
right.” Graves v. City of Coeur d’Alene, 
339 F.3d 828
, 846
(9th Cir. 2003), abrogation on other grounds recognized in
OTR Wheel Eng’g, Inc. v. West Worldwide Servs., Inc.,
897 F.3d 1008
, 1016 (9th Cir. 2018).

     1. Terry stop

    Existing precedent forecloses Skinner’s and
Hernandez’s arguments that Reynaga’s right to be free from
a Terry stop absent reasonable suspicion was not clearly
established in these circumstances. Melendres clearly
establishes the law that governs the Fourth Amendment right
implicated by Reynaga’s unlawful Terry stop. Skinner
stopped Reynaga solely on the basis of Hernandez’s
statement that a witness had testified that Reynaga was “not
a legal citizen.” Melendres—which was decided in 2012,
almost five years before Skinner stopped Reynaga—held
that “detaining individuals based solely on reasonable
suspicion or knowledge that a person was unlawfully present
in the United States” is not sufficiently “premised on
              REYNAGA HERNANDEZ V. SKINNER                          23

criminality” to be justified under 
Terry. 695 F.3d at 1000
–
1001.

    Skinner detained Reynaga based solely on knowledge
that he was unlawfully present in the United States.
Reynaga’s right to be free from detention absent reasonable
suspicion in this context was clearly established at the time
of the stop.

    2. Arrest

    Neither are Skinner and Hernandez entitled to qualified
immunity for Skinner’s unlawful arrest of Reynaga. For the
reasons discussed, Skinner arrested Reynaga when he
handcuffed Reynaga and detained him in the patrol car. 4

    The Supreme Court and our own court long ago
established an immigrant’s right to be free from arrest absent
probable cause that he has entered the country unlawfully.
Officers may, during a justified Terry stop, question
individuals “about their citizenship and immigration status,
and . . . may ask them to explain suspicious circumstances,
but any further detention or search must be based on consent
or probable cause.” United States v. Brignoni-Ponce,
422 U.S. 873
, 881–82 (1975).

    In Gonzales v. City of Peoria, published in 1983, we held
that an individual’s “lack of documentation or other

    4
       Skinner and Hernandez also briefly argue that the district court
misapplied the collective-knowledge doctrine. They assert that because
Skinner was “working in concert with ICE, the information ICE had as
to probable cause for the arrest of [Reynaga] could . . . be imputed to
Skinner.” Op. Br. 44. Because we conclude Reynaga was arrested when
he was handcuffed and placed in the patrol car—prior to Skinner’s phone
call to ICE—we do not address this doctrine.
24               REYNAGA HERNANDEZ V. SKINNER

admission of illegal presence” does not, “without more,
provide probable cause of the criminal violation of illegal
entry.” 722 F.2d at 476
–77. Arresting officials must “be
able to distinguish between criminal and civil violations and
the evidence pertinent to each.”
 Id. at 477. 
We re-
emphasized this in Martinez-Medina, explaining that an
immigrant’s “admission of illegal presence . . . does not,
without more, provide probable cause of the criminal
violation of illegal entry,” which “remain[ed], the law of the
circuit, binding on law enforcement 
officers.” 673 F.3d
at 1036 
(quoting 
Gonzales, 722 F.2d at 476
–77).

    We have also stated, in varying contexts, that the other
factors upon which Skinner relied to arrest Reynaga are
minimally probative of the crime of illegal entry. In Manzo-
Jurado, we held that a group of “individuals’ appearance as
a Hispanic work crew, inability to speak English, proximity
to the border, and unsuspicious behavior” 5 did not even
amount to reasonable suspicion of illegal 
entry. 457 F.3d
at 940
; see also 
Benitez-Mendez, 752 F.2d at 1311 
(holding
that an immigrant was unlawfully seized by a Border Patrol
officer where the officer knew only that he “was a field
worker whose co-workers fled upon sight of a marked
Border Patrol detail,” was an “alien,” and “claimed to
possess documents showing his legal status”).

   In Gonzales, we cautioned that “an arresting officer
cannot assume that [a noncitizen] who admits he lacks
proper documentation” committed a crime; “the lack of
documentation or other admission of illegal presence may be
some indication of illegal entry,” but “it does not, without
more, provide probable cause of the criminal 
violation[.]”
722 F.2d at 476
–77; see also Tatum v. City & County of San

     
5
         457 F.3d at 932
.
            REYNAGA HERNANDEZ V. SKINNER                  25

Francisco, 
441 F.3d 1090
, 1094–95 (9th Cir. 2006).
Likewise, an individual’s language skills, without more, do
not constitute probable cause. See 
Brignoni-Ponce, 422 U.S.
at 886
–87 (recognizing that a widespread characteristic
“standing alone . . . does not justify stopping all Mexican-
Americans to ask if they are aliens”); 
Manzo-Jurado,
457 F.3d at 936
–37 (concluding that a lack of language skills
standing alone does not even rise to the level of reasonable
suspicion); see also United States v. Rodriguez, 
976 F.2d
592
, 595–96 (9th Cir. 1992) (explaining that in evaluating
whether reasonable suspicion has been met, courts “must not
accept what has come to appear to be a prefabricated or
recycled profile of suspicious behavior very likely to sweep
many ordinary citizens into a generality of suspicious
appearance merely on hunch”). Together, these cases
sufficiently constitute the “body of relevant case law . . .
necessary to clearly establish the answer with respect to
probable cause.” District of Columbia v. Wesby, 
138 S. Ct.
577
, 590 (2018) (internal quotation marks omitted).

    Reynaga’s right to be free from arrest absent probable
cause that he entered the country unlawfully has been
established since at least 2012, by which time we had
published both Melendres and Martinez-Medina, and
arguably as early as Gonzales, in 1983.

                            IV.

    We affirm the district court’s denial of qualified
immunity for both Skinner and Hernandez. Skinner stopped
and arrested Reynaga without reasonable suspicion or
probable cause, respectively, and Hernandez integrally
participated in his actions. Reynaga’s right to be free from
unlawful stops in this circumstance has been established
since at least 2012, by which time both Melendres and
Martinez-Medina were law of the circuit.
26        REYNAGA HERNANDEZ V. SKINNER

     AFFIRMED.