FOR PUBLICATION

UNITED STATES COURT OF APPEALS

FOR THE NINTH CIRCUIT

GREGORIO PEREZ CRUZ,

Petitioner,

v.

WILLIAM P. BARR, Attorney General,

Respondent.

No. 15-70530

Agency No.

A095-748-837

OPINION

On Petition for Review of an Order of the

Board of Immigration Appeals

Argued and Submitted September 5, 2018

San Francisco, California

Filed June 13, 2019

Before: Marsha S. Berzon and Michelle T. Friedland, 

Circuit Judges, and Daniel R. Dominguez,* District Judge.

Opinion by Judge Berzon

 * The Honorable Daniel R. Dominguez, United States District Judge 

for the District of Puerto Rico, sitting by designation.
2 PEREZ CRUZ V. BARR

SUMMARY**

Immigration

Granting Gregorio Perez Cruz’s petition for review of a 

decision of the Board of Immigration Appeals, the panel held 

that Immigration and Customs Enforcement (ICE) agents 

were not permitted to carry out preplanned mass detentions, 

interrogations, and arrests at a factory, without 

individualized reasonable suspicion, and reversed and 

remanded to the BIA with instructions to dismiss Perez 

Cruz’s removal proceedings without prejudice.

During the execution of a search warrant for 

employment-related documents located at the factory where 

Perez Cruz worked, he was detained, interrogated, and 

arrested for immigration violations, along with 

approximately 130 other workers. He was subsequently 

placed in removal proceeding and charged with entry 

without inspection. Based on statements he provided during 

his detention, ICE prepared a Form I-213, alleging that Perez 

Cruz had admitted that he was brought illegally into the 

United States as a child. The government also produced 

Perez Cruz’s birth certificate based on statements he 

provided in connection with the factory raid. Perez Cruz 

moved to terminate the proceedings or, in the alternative, 

suppress evidence, but the BIA concluded that his detention 

and interrogation violated neither the agency’s regulation 

nor the Fourth Amendment.

 ** This summary constitutes no part of the opinion of the court. It 

has been prepared by court staff for the convenience of the reader.
PEREZ CRUZ V. BARR 3

The panel first rejected the government’s contention that, 

even if Perez Cruz were otherwise entitled to suppression, 

the critical evidence in question constituted evidence only of 

“identity” and so was not subject to suppression under INS 

v. Lopez-Mendoza, 468 U.S. 1032 (1984). The panel 

concluded that this argument was flatly contradicted by 

Lopez-Rodriguez v. Mukasey, 536 F.3d 1012 (9th Cir. 2008), 

which held that evidence pertaining to alienage is subject to 

suppression, and expressly instructed that, however broadly 

identity evidence reaches, it does not include evidence 

pertaining to alienage. Concluding that Perez Cruz’s 

statements regarding his birthplace, and his birth certificate 

derived from those statements, constituted evidence of 

alienage—not identity—the panel rejected the government’s 

argument that the evidence was not suppressible.

The panel next rejected the government’s contention that 

Perez Cruz’s detention was permitted by Michigan v. 

Summers, 452 U.S. 692 (1981), which held that a warrant to 

search for contraband founded on probable cause implicitly 

carries with it the limited authority to detain the occupants 

of the premises while a proper search is conducted. 

The panel held that Summers’ categorical authority to 

detain incident to the execution of a search warrant does not 

extend to a preexisting plan whose central purpose is to 

detain, interrogate, and arrest a large number of individuals 

without individualized reasonable suspicion. In concluding 

that the purpose behind the agents’ conduct was relevant 

here, the panel explained that the purpose behind a search or 

seizure is often relevant when suspicionless intrusions 

pursuant to a general scheme—such as inventory and 

administrative searches—are at issue. The panel also 

explained that there is no meaningful difference between the 

categorical authority to detain without reasonable suspicion 
4 PEREZ CRUZ V. BARR

under Summers and the suspicionless intrusions for which 

the Supreme Court has held that a valid purpose is a 

prerequisite. 

The panel further observed that, in the context of 

determining whether an administrative search is invalid due 

to an impermissible purpose, the court asks whether the 

officer would have made the stop in the absence of the 

impermissible purpose. The panel concluded that Perez 

Cruz had satisfied this burden, explaining that ICE planning 

documents showed that the central purpose of the raid was 

not to find documents but to arrest undocumented workers.

Accordingly, the panel concluded that Perez Cruz’s 

seizure was not a permissible Summers detention and that the 

agents therefore violated 8 C.F.R. § 287.8(b)(2), which 

requires an immigration officer to have “reasonable 

suspicion, based on specific articulable facts, that a person 

being questioned is, or is attempting to be, engaged in an 

offense against the United States or is an alien illegally in the 

United States” in order to briefly detain the person for 

questioning. Noting that prejudice may be presumed 

where—as here—compliance with a regulation is mandated 

by the Constitution, the panel presumed prejudice and 

concluded that Perez Cruz was entitled to suppression of the 

evidence in question.

Finally, the panel concluded that the proceedings should 

be terminated without prejudice because the government had 

not offered any evidence of Perez Cruz’s alienage beyond 

the Form I-213 and his birth certificate—fruits of the 

regulatory violation. The panel thus granted the petition for 

review and remanded to the BIA with instructions to dismiss 

his removal proceedings without prejudice.
PEREZ CRUZ V. BARR 5

COUNSEL

Ahilian T. Arulanantham (argued), Sameer Ahmed, ACLU 

of Southern California, Los Angeles, California; Noemi G. 

Ramirez, Los Angeles, California, for Petitioner.

Walter Bocchini (argued), Trial Attorney, Linda S. Wernery, 

Assistant Director, Office of Immigration Litigation; Chad 

A. Readler, Acting Assistant Attorney General, United 

States Department of Justice, Washington, D.C., for 

Respondent.

Kristin Macleod-Ball, Melissa Crow, American Immigration 

Council, Washington, D.C.; Matthew E. Price, Jenner & 

Block LLP, Washington, D.C., for Amicus Curiae American 

Immigration Council.

OPINION

BERZON, Circuit Judge:

Immigration and Customs Enforcement (ICE) agents 

implemented a preconceived plan to “target” over 200 

factory workers for detention and for interrogation as to their 

immigration status. The plan turned on obtaining and 

executing a search warrant for employment records at the 

factory. The record before us establishes that the search 

warrant for documents was executed “in order to” arrest 

undocumented workers present at the factory. Our central 

question is whether the ICE agents were permitted to carry 

out preplanned mass detentions, interrogations, and arrests 

at the factory, without individualized reasonable suspicion. 

We hold that they were not.
6 PEREZ CRUZ V. BARR

I

A

In March 2006, ICE received an anonymous tip that 

Micro Solutions Enterprises (MSE), a Los Angeles-area 

manufacturer of printer cartridges, employed 200 to 300 

undocumented immigrants. Nearly two years later, in 

February 2008, ICE agents sought and received a search 

warrant for employment-related documents located at the 

MSE factory in Van Nuys, California, and criminal 

complaints and arrest warrants for eight MSE employees.1

Documents later obtained2 revealed that ICE intended 

from the outset to turn the execution of these warrants into 

quite a different operation than a search for employment 

records. An internal memorandum issued before the 

operation stated that ICE “[would] be conducting a search 

warrant and expects to make 150–200 arrests.” The 

memorandum also noted that ICE would have “2 buses and 

5 vans” ready to transport potential detainees from the 

factory and “200 detention beds available to support the 

operation.” Another planning document noted that ICE 

“anticipate[d] executing a federal criminal search warrant at 

 1 The record does not reflect why ICE took so long to act on the 

anonymous tip.

2 These documents were obtained by the ACLU of Southern 

California and the Los Angeles Chapter of the National Lawyers Guild 

as a result of a Freedom of Information Act (FOIA) request by the 

National Immigration Law Center, made after the MSE factory search. 

The request resulted in a settlement providing for the release of these 

documents, among others. See Order, Nat’l Immigration Law Ctr. v. U.S. 

Dep’t of Homeland Sec., No. 2:08-cv-07092-DDP-VBK (C.D. Cal. Feb. 

1, 2011), ECF No. 33.
PEREZ CRUZ V. BARR 7

MSE in order to administratively arrest as many as 100 

unauthorized workers” (emphasis added).

B

The operation took place as planned. Two days after the 

warrants were issued, approximately 100 armed and 

uniformed ICE agents streamed into the MSE factory. 

Blocking all visible exits, the agents ordered all workers to 

stop working and announced that no one was permitted to 

leave. The agents prohibited the workers from contacting 

anyone using their cellphones and allowed them to use the 

restroom only with an ICE escort. Among the workers 

detained was Gregorio Perez Cruz, a native and citizen of 

Mexico who entered the United States without inspection in 

1994.

The ICE agents then separated the men and women into 

different areas. The women were taken to the factory 

cafeteria, and the men were instructed to wait in a large 

hallway outside the cafeteria. After the men, including Perez 

Cruz, had gathered in the hallway, the agents ordered them 

to form two lines, one for individuals who possessed work 

authorization documents and another for those who lacked 

work authorization. Those who joined the line for men who 

had work authorization were escorted out of the hallway. 

Perez Cruz remained in the hallway but did not join either 

line.

The ICE agents next ordered Perez Cruz and the other 

remaining men to stand against the wall. While Perez Cruz 

and the others were standing the agents conducted a pat 

down of each of them. The agent who frisked Perez Cruz 

took his wallet. The detainees were then handcuffed and 

questioned. While Perez Cruz was handcuffed, the agents 

asked him his name, his nationality, his date of birth, and the 
8 PEREZ CRUZ V. BARR

length of time he had worked at the factory. The agents then 

escorted Perez Cruz and the other detained male workers 

into another hallway, where they were questioned again. At 

some point during his detention, Perez Cruz provided 

statements to the agents indicating that he lacked lawful 

immigration status.

Sometime later, the ICE agents began taking groups of 

workers to buses parked outside the factory. When it came 

time for Perez Cruz to board the bus, an agent photographed 

him and asked again for his name and country of origin. 

Perez Cruz, still handcuffed, was kept on the bus for over an 

hour before he was taken to a detention facility in downtown 

Los Angeles.

When the bus arrived at the detention facility, ICE agents 

ordered Perez Cruz off the bus, searched him again, and 

removed his handcuffs. Perez Cruz was then held at the 

detention facility overnight. During the night, he was 

interrogated again. The next day, still detained, Perez Cruz 

was interrogated once more. At around 1:00 a.m. he was 

released. According to a later ICE press release, Perez Cruz 

was one of 130 workers at the MSE factory arrested for 

immigration violations.

C

About a month later, Perez Cruz received a notice to 

appear for a removal hearing. The notice charged him as 

removable for entry without inspection. Based on the 

statements Perez Cruz provided during his detention, ICE 

agents prepared a Form I-213 alleging that Perez Cruz had 

admitted that he was brought illegally into the United States 

as a child. In addition to the Form I-213, the government 

produced Perez Cruz’s birth certificate, obtained by an ICE 
PEREZ CRUZ V. BARR 9

agent in Mexico based on the statements Perez Cruz had 

provided in connection with the factory raid.

Perez Cruz moved to terminate the proceedings or, in the 

alternative, suppress the evidence gathered, arguing that his 

arrest and interrogation violated binding federal regulations 

as well as the Fourth and Fifth Amendments. There was a 

brief hearing on Perez Cruz’s motions, during which the 

government did not contest any of Perez Cruz’s factual 

assertions. The immigration judge (IJ) granted Perez Cruz’s 

motion to terminate, concluding that ICE’s initial detention 

of Perez Cruz and failure to advise Perez Cruz of his rights 

“violated [ICE’s] own regulation.” Relying on Matter of 

Garcia-Flores, 17 I. & N. Dec. 325 (B.I.A. 1980), the IJ held 

that, because Perez Cruz was prejudiced by this regulatory 

violation, termination of his removal proceedings was 

warranted. Accordingly, the IJ did not reach Perez Cruz’s 

constitutional claims.

The government appealed, and the Board of Immigration 

Appeals (BIA) reversed. The BIA relied on Michigan v. 

Summers, 452 U.S. 692 (1981), which held valid the 

detention of residents of a home where a search warrant was 

being executed. Under Summers, the BIA concluded, Perez 

Cruz’s detention and arrest violated neither the agency’s 

regulations nor the Fourth Amendment. Because law 

enforcement officers are permitted to “secure the premises 

both for purposes of their own safety and in order to prevent 

the destruction of evidence” during the execution of a 

warrant, the BIA reasoned, the ICE agents did not violate the 

Fourth Amendment by “ordering employees to stop 

working, blocking exits, and asking employees to selfidentify their immigration or citizenship status.” The BIA 

also concluded that, even if the detention was improper, the 

evidence introduced by the government was offered to prove 
10 PEREZ CRUZ V. BARR

only Perez Cruz’s “identity” and therefore could not be 

suppressed.

On remand from the BIA, the IJ entered a removal order 

against Perez Cruz. When Perez Cruz again appealed, the 

BIA affirmed the IJ’s order and dismissed the appeal.

Perez Cruz timely petitioned this court for review of the 

BIA’s decisions. He argues, among other things, that his 

detention violated both the Fourth Amendment and 

controlling regulations, and that the evidence against him 

should therefore have been suppressed.

II

We first briefly address the government’s contention that 

even if Perez Cruz were otherwise entitled to suppression of 

the evidence obtained as a result of the MSE mass detention 

and arrest, the critical evidence in question—Perez Cruz’s 

statements as represented in the Form I-213, and his birth 

certificate—constitutes evidence only of “identity” and so is 

not subject to suppression. This argument is squarely 

foreclosed by precedent interpreting the reach of INS v. 

Lopez-Mendoza, 468 U.S. 1032 (1984).

Lopez-Mendoza determined that “[t]he ‘body’ or identity 

of a defendant or respondent in a criminal or civil proceeding 

is never itself suppressible as a fruit of an unlawful arrest, 

even if it is conceded that an unlawful arrest, search, or 

interrogation occurred.” Id. at 1039. On that basis, LopezMendoza concluded that an immigrant who “objected only 

to the fact that he had been summoned to a deportation 

hearing following an unlawful arrest” could not raise a 

Fourth Amendment claim. Id. at 1040. We have applied 

Lopez-Mendoza beyond the context of mandatory 

appearance for trial or hearing, holding that “identity 
PEREZ CRUZ V. BARR 11

evidence cannot be suppressed.” United States v. GarciaBeltran, 443 F.3d 1126, 1133 (9th Cir. 2006) (emphasis 

added).3

In Perez Cruz’s removal proceedings, the government 

offered statements Perez Cruz made during the factory 

interrogation regarding his country of origin. It also offered 

his birth certificate, obtained as a result of Perez Cruz’s 

statements at the factory about his birthplace. According to 

the government, the statements and birth certificate are proof 

only of “identity” and therefore not subject to suppression. 

That evidence, the government maintains, is sufficient to 

establish Perez Cruz’s removability. In so arguing, the 

government seeks to expand evidence of one’s identity to 

include evidence used to establish alienage—namely, Perez 

Cruz’s statements regarding his country of origin and his 

birth certificate.

The government’s position is flatly contradicted by 

Lopez-Rodriguez v. Mukasey, 536 F.3d 1012 (9th Cir. 2008). 

Lopez-Rodriguez concluded that “evidence of alienage” 

resulting from an egregious Fourth Amendment violation—

 3 Our interpretation of Lopez-Mendoza has not been universally 

accepted. The Second, Fourth, Eighth, and Tenth Circuits have held that 

Lopez-Mendoza “merely confirmed the jurisdictional rule that an 

unlawful arrest has no bearing on the validity of a subsequent 

proceeding,” rather than “creat[ing] an evidentiary rule insulating 

specific pieces of identity-related evidence from suppression.” 

Pretzantzin v. Holder, 736 F.3d 641, 646–47, 646 n.6 (2d Cir. 2013); see

also United States v. Ortiz-Hernandez, 427 F.3d 567, 581–82 (9th Cir. 

2005) (W. Fletcher, J., dissenting). We are bound, however, by our 

somewhat broader interpretation of Lopez-Mendoza, which accords with 

that of several other circuits. See United States v. Chagoya-Morales, 

859 F.3d 411, 419 & n.14 (7th Cir. 2017) (collecting cases from this 

court, as well as the First, Third, Fifth, Sixth, Seventh, and Eleventh 

Circuits).
12 PEREZ CRUZ V. BARR

namely, the petitioner’s statements “acknowledg[ing] that 

she was a native and citizen of Mexico”—should have been 

suppressed. Id. at 1014–15. In so concluding, LopezRodriguez reaffirmed that “the identity of an alien in 

removal proceedings is ‘never itself suppressible as a fruit of 

an unlawful arrest.’” Id. at 1015 n.5 (quoting LopezMendoza, 468 U.S. at 1039). But, Lopez-Rodriguez held, 

“evidence . . . pertaining to alienage” is subject to 

suppression. Id. However broadly “identity” evidence 

reaches, Lopez-Rodriguez expressly instructs that it does not 

include evidence “pertaining to alienage.” Id.

Lopez-Rodriguez’s conclusion is bolstered by the 

Supreme Court’s reasoning in Lopez-Mendoza itself. LopezMendoza was careful to distinguish between identity and 

alienage, recognizing that, “[s]ince the person and identity 

of the respondent are not themselves suppressible, the 

[government] must prove only alienage.” 468 U.S. at 1043. 

If alienage were bound up in identity, as the government 

presently contends, then Lopez-Mendoza would have had no 

need to make this point.

Here, as in Lopez-Rodriguez, the government relied on 

alienage evidence alleged to be the fruit of unlawful 

government conduct. See 536 F.3d at 1015. The I-213 form 

notes, for example, that Perez Cruz “was born in Puebla, 

Mexico on 9/6/1985.” Perez Cruz’s birth certificate, too, was

obtained based on his statement that he was born in Puebla, 

Mexico. The ICE agent who obtained the birth certificate in 

Mexico stated in his declaration that he was assigned to 

obtain a birth certificate “for Gregorio Perez, also known as 

Gregorio Perez Cruz, who was born on September 6, 1985, 

in the State of Puebla Mexico.”

If Perez Cruz can demonstrate that his statements 

regarding his birthplace, and his birth certificate derived 
PEREZ CRUZ V. BARR 13

from those statements, were the fruit of impermissible 

government action, they are suppressible as evidence of 

alienage, not identity. See id. at 1015 n.5. We therefore reject 

the government’s argument that the evidence sufficient to 

prove Perez Cruz’s removability is not suppressible.

III

We turn to the merits of Perez Cruz’s illegal detention 

and interrogation claim.

As a general matter, the Fourth Amendment’s 

exclusionary rule does not apply to immigration 

proceedings. See Lopez-Mendoza, 468 U.S. at 1050–51. 

There are, however, two longstanding exceptions: (1) “when 

the agency violates a regulation promulgated for the benefit 

of petitioners and that violation prejudices the petitioner’s 

protected interests” and (2) “when the agency egregiously 

violates a petitioner’s Fourth Amendment rights.” Sanchez 

v. Sessions, 904 F.3d 643, 649 (9th Cir. 2018); see also

Adamson v. Comm’r, 745 F.2d 541, 546 (9th Cir. 1984) 

(egregious Fourth Amendment violations); United States v. 

Calderon-Medina, 591 F.2d 529, 531–32 (9th Cir. 1979) 

(regulatory violations). Perez Cruz argues that suppression 

of the evidence in his removal proceedings is warranted 

because his detention constituted either a violation of an ICE 

regulation or an egregious violation of the Fourth 

Amendment.

A

First, did Perez’s detention violate any regulation or the 

Fourth Amendment? At this juncture, it does not matter 

whether Perez Cruz’s detention is considered under the 

regulation or under the Fourth Amendment, because the 
14 PEREZ CRUZ V. BARR

regulatory standards are at least as stringent as those 

imposed by the Fourth Amendment.

Perez Cruz relies primarily on 8 C.F.R. § 287.8(b)(2), 

which provides as follows:

If the immigration officer has a reasonable 

suspicion, based on specific articulable facts, 

that the person being questioned is, or is 

attempting to be, engaged in an offense 

against the United States or is an alien 

illegally in the United States, the immigration 

officer may briefly detain the person for 

questioning.

8 C.F.R. § 287.8(b)(2). Recently, this court recognized that 

§ 287.8(b)(2) “serves a ‘purpose of benefit to the alien’” and 

that evidence gathered in violation of § 287.8(b)(2) may 

therefore be suppressed where “the violation ‘prejudiced 

interests of the alien which were protected.’” Sanchez, 

904 F.3d at 650 (quoting Garcia-Flores, 17 I. & N. Dec. at 

328).

As Sanchez explained, § 287.8(b)(2) “was intended to 

reflect constitutional restrictions on the ability of 

immigration officials to interrogate and detain persons in this 

country,” thereby providing at least as much protection as 

the Fourth Amendment. Id. at 651.4 Although § 287.8(b)(2) 

does not expressly allow for exceptions to its requirements, 

both parties assume that a so-called Summers detention 

 4 If anything, the regulation is stricter than the Fourth Amendment. 

On its face, the regulation requires reasonable suspicion in every instance 

before a person can be detained for questioning by an immigration 

officer. See 8 C.F.R. § 287.8(b)(2). So understood, the regulation might 

not permit exceptions to the reasonable suspicion requirement.
PEREZ CRUZ V. BARR 15

would be permitted under the regulation. We may likewise 

assume that Summers applies to detentions conducted under 

§ 287.8(b)(2), as we conclude that, even under Summers, the 

detention and interrogation were not permitted.

The government does not dispute that Perez Cruz was 

seized for purposes of the Fourth Amendment when he was 

detained in his workplace, frisked, and handcuffed, or that 

the ICE agents did so without individualized reasonable 

suspicion. Rightly so. The record confirms that the agents 

detained Perez Cruz and his coworkers at the outset of the 

raid, blocking all exits and prohibiting them from leaving. 

That ICE suspected MSE was employing undocumented 

workers did not provide reasonable suspicion that Perez 

Cruz himself was undocumented. It is a fundamental tenet of 

Fourth Amendment law that “a search or seizure of a person 

must be supported by probable cause particularized with 

respect to that person.” Ybarra v. Illinois, 444 U.S. 85, 91 

(1979). Stated differently, “a person’s mere propinquity to 

others independently suspected of [unlawful] activity does 

not, without more, give rise to probable cause to search [or 

seize] that person.” Id.

“Reasonable suspicion” is no different. “[T]he [Terry v. 

Ohio, 392 U.S. 1 (1968)] exception,” for example, “does not 

permit a frisk for weapons on less than reasonable belief or 

suspicion directed at the person to be frisked, even though 

that person happens to be on premises where an authorized

. . . search is taking place.” Id. at 94.

The government maintains that, despite this bedrock 

principle, Michigan v. Summers permitted the agents to 

detain Perez Cruz without suspicion on their arrival at the 

MSE factory to execute the search warrant they had in hand. 

See 452 U.S. at 705. As a result, the government argues, the 

agents did not violate the Fourth Amendment or 
16 PEREZ CRUZ V. BARR

§ 287.8(b)(2). The BIA agreed and consequently refused to 

suppress the evidence of Perez Cruz’s alienage.

The parties do not dispute that the underlying search 

warrant in this case is of a type that would support a 

Summers detention. Cf. Alexander v. City & County of San 

Francisco, 29 F.3d 1355, 1363 (9th Cir. 1994), abrogated on 

other grounds by County of Los Angeles v. Mendez, 137 S. 

Ct. 1539 (2017).5 We shall so assume. Our inquiry, then, 

turns on whether Perez Cruz’s seizure was justified as a valid 

Summers detention. It was not.

B

1

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.” U.S. 

Const. amend. IV. “[T]he general rule,” confirmed by 

“centuries of precedent,” is “that Fourth Amendment 

seizures are ‘reasonable’ only if based on probable cause.” 

Dunaway v. New York, 442 U.S. 200, 213–14 (1979).

Conversely, if a seizure is supported by probable cause, 

“[t]hat action [is] reasonable ‘whatever the subjective intent’ 

motivating the relevant officials.” Ashcroft v. al-Kidd, 

 5 Alexander held that officers were not entitled to rely on Summers

to detain individuals during the execution of an “administrative 

inspection warrant,” reasoning that “[m]any of [Summers’s 

justifications] simply do not hold true when the underlying warrant is an 

administrative warrant rather than a criminal search warrant.” 29 F.3d 

at 1363. Similarly, Sharp v. County of Orange, 871 F.3d 901 (9th Cir. 

2017), held that Summers does not provide “the categorical authority to 

detain co-occupants of a home incident to the in-home execution of an 

arrest warrant.” Id. at 915 (emphasis omitted).
PEREZ CRUZ V. BARR 17

563 U.S. 731, 736 (2011) (quoting Whren v. United States, 

517 U.S. 806, 814 (1996)). In other words, “[s]ubjective 

intentions play no role in ordinary, probable-cause Fourth 

Amendment analysis.” Whren, 517 U.S. at 813. But—and 

this point is the critical one for present purposes—“purpose 

is often relevant when suspicionless intrusions pursuant to a 

general scheme are at issue.” City of Indianapolis v. 

Edmond, 531 U.S. 32, 47 (2000) (emphasis added). In those 

circumstances, unlike where probable cause or reasonable 

suspicion exists, “‘actual motivations’ do matter.’” al-Kidd, 

563 U.S. at 736 (emphasis added) (quoting United States v. 

Knights, 534 U.S. 112, 122 (2001)); see also Whren, 

517 U.S. at 811.

Consider, for example, the inventory search exception, 

under which police may conduct a warrantless search of an 

impounded vehicle in accordance with standardized 

procedures. See Colorado v. Bertine, 479 U.S. 367, 371 

(1987). The Supreme Court has emphasized that “an 

inventory search must not be a ruse for a general rummaging 

in order to discover incriminating evidence.” Florida v. 

Wells, 495 U.S. 1, 4 (1990). Thus, such searches are 

permissible only if “there [is] no showing that the police . . . 

acted in bad faith or for the sole purpose of investigation.” 

Bertine, 479 U.S. at 372; see also United States v. Cervantes, 

703 F.3d 1135, 1141 (9th Cir. 2012).

A similar principle applies to the exception for 

administrative searches, which are permitted “when special 

needs, beyond the normal need for law enforcement, make 

the warrant and probable-cause requirement impracticable.” 

Vernonia Sch. Dist. 47J v. Acton, 515 U.S. 646, 653 (1995) 

(quoting Griffin v. Wisconsin, 483 U.S. 868, 873 (1987)); see 

also Eve Brensike Primus, Disentangling Administrative 

Searches, 111 Colum. L. Rev. 254, 276 (2011). 
18 PEREZ CRUZ V. BARR

Administrative searches of public school students, see New 

Jersey v. T.L.O., 469 U.S. 325, 341 (1985), or of 

probationers, see Knights, 534 U.S. at 121, may be supported 

by less than probable cause. And no suspicion at all is 

required for enforcement of certain regulatory schemes, such 

as routine inspections of residences for housing code 

violations, see Camara v. Mun. Court, 387 U.S. 523, 538 

(1967), or of businesses in a closely regulated industry, see

New York v. Burger, 482 U.S. 691, 708 (1987). Such 

searches do not violate the Fourth Amendment as long as the 

government “had proper regulatory purposes for enacting 

the administrative scheme” and “[t]here is . . . no reason to 

believe that the instant inspection was actually a ‘pretext’ for 

obtaining evidence of . . . violation of the penal laws.” Id. at 

716 n.27; see also Edmond, 531 U.S. at 41.

Under these no-probable-cause circumstances, “the 

exemption from the need for probable cause (and warrant), 

which is accorded to searches made for the purpose of 

inventory or administrative regulation, is not accorded to 

searches that are not made for those purposes.” Whren, 

517 U.S. at 811–12. Without an inquiry into purpose, these 

exceptions would provide officers with “a purposeful and 

general means of discovering evidence of crime,” which the 

Fourth Amendment forbids. Wells, 495 U.S. at 4 (quoting 

Bertine, 479 U.S. at 376 (Blackmun, J., concurring)).

A focus on purpose where there is no probable cause or 

reasonable suspicion for the search or seizure effectuates the 

original meaning of the Fourth Amendment. “It is familiar 

history that indiscriminate searches and seizures conducted 

under the authority of ‘general warrants’ were the immediate 

evils that motivated the framing and adoption of the Fourth 

Amendment.” Payton v. New York, 445 U.S. 573, 583 

(1980). “[T]he Amendment’s ban on too-loose warrants 
PEREZ CRUZ V. BARR 19

served to reaffirm the common law’s general resistance to 

conferring discretionary authority on ordinary officers.” 

Thomas Y. Davies, Recovering the Original Fourth 

Amendment, 98 Mich. L. Rev. 547, 724 (1999); see also

Laura K. Donohue, The Original Fourth Amendment, 83 U. 

Chi. L. Rev. 1181, 1323–24 (2016). The uncabined 

discretion potentially provided by these Fourth Amendment 

exceptions is not unlike the authority provided by the general 

warrants abhorred by the Framers. See Davies, supra, at 

736–38. A limit on the permissible purposes for which these 

exceptions may be used limits the exceptions to the 

circumstances that generated them and so furthers the 

original understanding of the Amendment.

2

The authority provided by Summers for detention during 

the execution of a valid search warrant applies in the absence 

of probable cause or reasonable suspicion as to the detained 

individuals’ culpability, and so is analogous to the probable 

cause exceptions for which valid purpose is a prerequisite.

In Summers, police officers detained George Summers 

as he left a house at which the officers were preparing to 

execute a search warrant. 452 U.S. at 693. The officers 

learned during the search that Summers owned the house. Id.

Drugs were found in the basement. Id. The officers then 

searched Summers and found an envelope containing heroin 

in his coat pocket. Id. Summers was charged with possession 

of that heroin. Id. at 694.

Summers moved to suppress the heroin as a fruit of his 

initial detention, for which, he argued, the officers had no 

probable cause. Id. at 694. Assuming that the detention “was 

unsupported by probable cause,” id. at 696, the Supreme 

Court nonetheless upheld it on the ground that “a warrant to 
20 PEREZ CRUZ V. BARR

search for contraband founded on probable cause implicitly 

carries with it the limited authority to detain the occupants 

of the premises while a proper search is conducted,” id.

at 705 (footnote omitted). Summers thereby created another 

limited exception to the Fourth Amendment’s general 

requirement that a seizure be supported by probable cause 

or, under some circumstances, reasonable suspicion. See

Dunaway, 442 U.S. at 213.

The Summers exception was reaffirmed in Muehler v.

Mena, 544 U.S. 93 (2005). There, police officers 

investigating a gang-related shooting obtained a search 

warrant for a suspected gang member’s residence. Id. at 95–

96. During the search the officers handcuffed and detained 

Iris Mena, who lived at the residence, and questioned her 

about her immigration status. Id. at 96. Mena sued the 

officers under 42 U.S.C. § 1983, arguing that the officers 

“should have released Mena as soon as it became clear that 

she posed no immediate threat” and that, as they had not 

done so, her detention violated the Fourth Amendment. Id.

at 96–97. The Court rejected that contention, emphasizing 

that “[a]n officer’s authority to detain incident to a search is 

categorical; it does not depend on the ‘quantum of proof 

justifying detention or the extent of the intrusion to be 

imposed by the seizure.’” Id. at 98 (quoting Summers, 

452 U.S. at 705 n.19). “[B]ecause a warrant existed to search 

[the house] and Mena was an occupant of that address at the 

time of the search,” the Court concluded, “Mena’s detention 

for the duration of the search was reasonable under 

Summers.” Id.

Summers and Mena both involved searches and 

detentions limited in scope. But this court has applied the 

Summers exception to cover somewhat broader searches and 

detentions. Dawson v. City of Seattle, 435 F.3d 1054 (9th 
PEREZ CRUZ V. BARR 21

Cir. 2006), for example, upheld the detention of the residents 

of two boarding houses while a search warrant was executed 

for evidence of rodent infestation and various municipal 

health code violations. Id. at 1066. Likewise, Ganwich v. 

Knapp, 319 F.3d 1115 (9th Cir. 2003), upheld the initial 

detention of several employees in a waiting room at a 

workplace being searched, concluding that “the officers’ 

holding the [employees] in the waiting room was precisely 

the conduct the Supreme Court deemed reasonable in 

Michigan v. Summers.” Id. at 1120–21 (citation omitted).6

These cases hold that, as a general matter, “the police may 

detain a building’s occupants while officers execute a search 

warrant as long as the detention is reasonable.” Dawson, 

435 F.3d at 1065. “[T]he duration of a detention may be 

coextensive with the period of a search, and require[s] no 

further justification.” Id. at 1066.

There is one critical—indeed, determinative—difference 

between those cases and this one. Perez Cruz has presented 

substantial, uncontroverted evidence that the search 

authorized by the warrant was far from the ICE agents’ 

central concern. Instead, the agents’ principal goal was to 

detain, interrogate, and arrest a large number of individuals 

who worked at the MSE factory, hoping to initiate removal 

proceedings against them. According to the FOIA-obtained 

documents, that was the “target” of the agents’ activity, and 

the agents came on the premises “in order to” arrest 

undocumented workers. Notwithstanding this transparent 

evidence concerning the purpose for entering the MSE 

 6 Ganwich ultimately held that the employees’ detention was 

unlawful, as “[t]he officers’ conduct was more intrusive than necessary 

to effectuate an investigative detention otherwise authorized by 

Summers, so it was not reasonable under the Fourth Amendment.” 

319 F.3d at 1124.
22 PEREZ CRUZ V. BARR

factory, the government asks us to authorize Perez Cruz’s 

detention under Summers. We cannot do so.

As the Supreme Court has explained, “Summers

recognized that a rule permitting the detention of occupants 

on the premises during the execution of a search warrant, 

even absent individualized suspicion, was reasonable and 

necessary in light of the law enforcement interests in 

conducting a safe and efficient search.” Bailey v. United 

States, 568 U.S. 186, 200 (2013). In permitting such 

detentions, “this exception grants substantial authority to 

police officers to detain outside of the traditional rules of the 

Fourth Amendment.” Id. Where “a safe and efficient search” 

is not the primary purpose of the officers’ actions, 

Summers’s justification for bypassing the Fourth 

Amendment’s traditional protections disappears, id., just as 

the justifications for doing so disappear—and so bypass of 

the usual Fourth Amendment requisites becomes 

impermissible—in inventory and administrative search 

cases.

We recognize that Summers detentions do presuppose a 

valid search warrant supported by probable cause. But 

search warrants based on probable cause cover the place 

being searched, not the seizure of individuals. Summers

requires no reasonable suspicion for an individual’s 

detention, nor need the magistrate who issues the warrant be 

told about, or approve, any detention of individuals, planned 

or otherwise. Again, under Summers, “[a]n officer’s 

authority to detain incident to a search is categorical; it does 

not depend on the ‘quantum of proof justifying detention or 

the extent of the intrusion to be imposed by the seizure.’” 

Mena, 544 U.S. at 98 (quoting Summers, 452 U.S. at 705 

n.19). There is no meaningful difference between the 

categorical authority to detain without reasonable suspicion 
PEREZ CRUZ V. BARR 23

during the execution of a search warrant and the 

“suspicionless intrusions pursuant to a general scheme” for 

which the Supreme Court has held purpose is relevant. 

Edmond, 531 U.S. at 47.

The law enforcement interests underlying Summers are 

fully consistent with this conclusion. “In Summers, the Court 

recognized three important law enforcement interests that, 

taken together, justify the detention of an occupant who is 

on the premises during the execution of a search warrant: 

officer safety, facilitating the completion of the search, and 

preventing flight.” Bailey, 568 U.S. at 194; see also

Summers, 452 U.S. at 702–03. These interests are parallel to 

those underlying the Fourth Amendment limitations 

applicable to suspicionless searches discussed above. 

Inventory searches, for example, are justified by “three 

distinct needs: the protection of the owner’s property while 

it remains in police custody, the protection of the police 

against claims or disputes over lost or stolen property, and 

the protection of the police from potential danger.” South 

Dakota v. Opperman, 428 U.S. 364, 369 (1976) (citations 

omitted). Yet the Supreme Court has long recognized that an 

inventory search is impermissible if “the police . . . acted in 

bad faith or for the sole purpose of investigation.” Bertine, 

479 U.S. at 372. “That Summers detentions aid police in 

uncovering evidence and nabbing criminals does not 

distinguish them from the mine run of seizures unsupported 

by probable cause, which the Fourth Amendment generally 

proscribes.” Bailey, 568 U.S. at 206 (Scalia, J., concurring).

In light of the interests underlying the Summers

exception, the Supreme Court’s reasoning in Bailey strongly 

supports the conclusion that Summers does not authorize 

Perez Cruz’s detention. Bailey held that officers may not rely 

on Summers to detain individuals who are found beyond “the 
24 PEREZ CRUZ V. BARR

immediate vicinity of a premises to be searched.” Id. at 201 

(majority opinion). “Limiting the rule in Summers to the area 

in which an occupant poses a real threat to the safe and 

efficient execution of a search warrant,” Bailey reasoned, 

“ensures that the scope of the detention incident to a search 

is confined to its underlying justification.” Id. (emphasis 

added). The Court explained that, “[o]nce an occupant is 

beyond the immediate vicinity of the premises to be 

searched, the search-related law enforcement interests are 

diminished and the intrusiveness of the detention is more 

severe.” Id. Bailey instructs that Summers does not approve 

a detention without any individualized suspicion where the 

officers’ primary purpose is not conducting “a safe and 

efficient search” pursuant to a warrant. Id. at 200. On the 

evidence before us, that was precisely the case here—the 

agents’ focus was not on conducting a safe search but on 

engaging in a preplanned investigation and detention of a 

large number of individuals present at the premises where 

the search was authorized.

Notably, in establishing the Summers exception, the 

Supreme Court emphasized that “the type of detention 

imposed here is not likely to be exploited by the officer or 

unduly prolonged in order to gain more information, because 

the information the officers seek normally will be obtained 

through the search and not through the detention.” 452 U.S. 

at 701. That assertion held true for the limited searches 

considered in Summers and Mena. But as the permissible 

applications of Summers have expanded—covering broader 

searches and a greater number of detentions, see, e.g., 

Dawson, 435 F.3d at 1066; Ganwich, 319 F.3d at 1120–21—

so has the potential for abuse.

As “[a]n exception to the Fourth Amendment rule 

prohibiting detention absent probable cause,” the authority 
PEREZ CRUZ V. BARR 25

granted by Summers “must not diverge from its purpose and 

rationale.” Bailey, 568 U.S. at 194. We hold that Summers’ 

categorical authority to detain incident to the execution of a 

search warrant does not extend to a preexisting plan whose 

central purpose is to detain, interrogate, and arrest a large 

number of individuals without individualized reasonable 

suspicion.

3

That the ICE agents here had some investigatory purpose 

in detaining Perez Cruz does not, on its own, invalidate their 

reliance on Summers. In applying the purposive limitation 

on administrative searches, we have “emphasize[d] that the 

presence of a criminal investigatory motive, by itself, does 

not render an administrative stop pretextual.” United States 

v. Orozco, 858 F.3d 1204, 1213 (9th Cir. 2017). “[A]n 

individual suspected of crime may be subjected to facially 

valid, broadly applicable search schemes on the same basis 

as other individuals—provided those schemes do, in fact, 

apply in his case.” United States v. Tsai, 282 F.3d 690, 695 

(9th Cir. 2002). Thus, in the administrative search context, 

to determine whether the search is invalid because of an 

impermissible purpose, “we ask whether the officer would

have made the stop in the absence of the invalid purpose.” 

Orozco, 858 F.3d at 1213 (quoting United States. v. Maestas, 

2 F.3d 1485, 1489 (10th Cir. 1993)). To meet this standard, 

“a defendant must show that the stop would not have 

occurred in the absence of an impermissible reason.” Id.

Perez Cruz has satisfied the Orozco burden. As the ICE 

planning documents unmistakably show, the agents’ plans 

here were centered on detaining and interrogating any and 

all workers located at the MSE factory to determine whether 

they were undocumented. One document, for example, 

stated that ICE was “targeting 150–200 undocumented 
26 PEREZ CRUZ V. BARR

workers” (emphasis added) during the operation, evidencing 

that arresting those workers, and not obtaining the 

documents mentioned in the warrant, was the focus of the 

operation. In fact, under “significant details” of the operation 

listed in that document, the search itself not mentioned at 

all—only the “targeted” workers, the “ratio of 

apprehensions” of men and women, and the office that ICE 

would be using “to detain and process all arrested 

individuals.” Another memorandum issued before the raid 

explained: “ICE anticipates executing a federal criminal 

search warrant at MSE in order to administratively arrest as 

many as 100 unauthorized workers believed to be from 

Mexico and Central America” (emphasis added). Those 

statements alone establish that the central purpose of the raid 

was not to find documents but to arrest undocumented 

workers.

Documents prepared after the raid reinforce the 

conclusion that the agents were focused on the detentions, 

not the search. Those post-raid memoranda don’t mention 

the search at all; instead they discuss—in great detail—the 

workers’ detention. And another of those documents 

confirmed that the operation “targeted approximately 150 

undocumented workers believed to be employed at [MSE].” 

(emphasis added).

The ICE agents’ conduct at the MSE factory and 

afterward also confirms that they understood the search for 

records to be of much less significance—if any—as 

compared to the detentions, interrogations, and arrests of 

workers. The record suggests that many more agents were 

dedicated to seizing the MSE workers than to searching for 

documents. Instead of participating in the document search, 

those agents present spent time corralling the workers, 

separating them by gender, handcuffing them, interrogating 
PEREZ CRUZ V. BARR 27

them, and searching them. Transportation and detention 

facilities for a large number of anticipated detainees were 

readied in advance, confirming that the agents had made 

careful plans to arrest these workers and take them offsite, 

rather than merely to detain them during the records search.

The agents’ repeated interrogations of Perez Cruz and his 

coworkers during their detention also demonstrate that the 

agents’ reliance on the Summers exception was misplaced. 

Mena authorizes officers to ask questions of Summers

detainees as long as the detention is not “prolonged by the 

questioning.” 544 U.S. at 100–01. But that authorization 

does not allow officers to conduct a Summers detention for 

the purpose of obtaining answers from detainees, let alone 

transporting detainees offsite and holding them long beyond 

the length of the search so they can be further interrogated, 

as occurred here. Mena did not abrogate the longstanding 

requirement that “if the person[] refuses to answer and the 

police take additional steps . . . to obtain an answer, then the 

Fourth Amendment imposes some minimal level of 

objective justification to validate the detention or seizure.” 

INS v. Delgado, 466 U.S. 210, 216–17 (1984).7

The IJ found that the agents “ordered” Perez Cruz and 

the other male workers to address whether they had work 

authorization by joining one of two lines. The agents then 

repeatedly questioned the workers who did not join the work 

authorization line until responses were provided. Perez Cruz, 

in particular, declined to answer the initial question, as he 

 7 We have similarly recognized that “law enforcement may not

require a person to furnish identification, if not reasonably suspected of 

any criminal conduct.” United States v. Landeros, 913 F.3d 862, 870 (9th 

Cir. 2019) (emphasis added); cf. Hiibel v. Sixth Judicial Dist. Court, 

542 U.S. 177, 187–88 (2004).
28 PEREZ CRUZ V. BARR

joined neither line. He was nonetheless detained and 

subjected to repeated questioning while detained. The nature 

of the agents’ questioning here indicates that they conducted 

the detentions for the purpose of engaging in mandatory 

interrogations. Mena does not authorize purposely targeted, 

mandatory interrogations after an individual declines to 

respond, as opposed to questioning incidental to the warrant 

execution purpose on which valid Summers detentions may 

be based.8

Notably, in contrast to the details regarding detentions, 

there is no information in the record about the search itself. 

It is therefore impossible to determine whether the agents 

even searched for the records purportedly sought, how long 

the search—if any—took, or whether the records search—if 

any—occurred anywhere near where the detentions took 

place.9 This dearth of detail further reinforces the suggestion 

 8 Again, two buses and vans arrived at the factory to detain the 

workers. Perez Cruz was detained, interrogated, and arrested at the 

factory. He was later transferred to a detention facility where he was 

questioned during the day and later that night. The next day, the 

questioning continued. He was ultimately released at 1:00 a.m. of the 

second night detained.

9 Even if some initial detention during a search for documents could 

have been justified under Summers, Perez Cruz’s detention likely 

exceeded anything that could be considered proper in scope, because the 

ICE agents appear to have departed even from the warrant itself. As we 

have already noted, the search warrant here authorized a search only for 

the employer’s records—presumably, paper documents or electronic 

files. Yet, the agents used the warrant’s authority to enter the working 

area and detain hundreds of workers. Why a search for records required 

going onto the floor of a large printer-cartridge factory is unclear. The 

record also suggests that the agents spent most of their time detaining 

and interrogating the workers rather than diligently executing the search 

warrant. See Ganwich, 319 F.3d at 1124 (“[H]ere the officers did 

precisely what the Summers Court warned was improper: the officers 
PEREZ CRUZ V. BARR 29

that the search was of secondary concern to the agents. 

Notably, that deficiency is entirely the government’s doing, 

as it expressly declined to offer any evidence to dispute 

Perez Cruz’s version of events.

In sum, Perez Cruz’s seizure was not a permissible 

Summers detention. The government suggests no other basis 

for Perez Cruz’s suspicionless detention and mandatory 

questioning. The agents thus violated 8 C.F.R. § 287.8(b)(2) 

by detaining and questioning Perez Cruz without 

“reasonable suspicion, based on specific articulable facts, 

that the person being questioned is, or is attempting to be, 

engaged in an offense against the United States or is an alien 

illegally in the United States.” 8 C.F.R. § 287.8(b)(2).10

 exploited the detention, prolonging it to gain information from the 

detainees, rather than from the search.”); cf. Rodriguez v. United States, 

135 S. Ct. 1609, 1616 (2015) (noting that the permissible length of a 

traffic stop is based on a “reasonably diligent” officer).

Ultimately, however, we need not decide whether the ICE agents 

otherwise exceeded the authority granted by Summers, because, given 

the clear evidence in the record here that the plan was focused on the 

detention of the workers, not the search for documents, even Perez 

Cruz’s initial detention was not justified.

10 As we noted above, the standards for § 287.8(b)(2) are at least as 

stringent as those applicable under the Fourth Amendment, see supra

Section III.A, so the agents’ actions also violated the Fourth 

Amendment. Because suppression is necessitated by the regulatory 

violation, we need not reach whether the agents’ Fourth Amendment 

violation was egregious. Cf. Orhorhaghe v. INS, 38 F.3d 488, 493 (9th 

Cir. 1994). For the same reason, we do not address Perez Cruz’s 

argument that his detention and interrogation violated the Fifth 

Amendment. See Gonzaga-Ortega v. Holder, 736 F.3d 795, 804 (9th Cir. 

2013).
30 PEREZ CRUZ V. BARR

C

Ordinarily, for a regulatory violation to warrant 

suppression, the violation must have prejudiced the 

petitioner. See Garcia-Flores, 17 I. & N. Dec. at 328–29. As 

Sanchez recognized, however, there is no need for Perez 

Cruz to identify prejudice for a violation of § 287.8(b)(2): 

“[W]here, as here, ‘compliance with the regulation is 

mandated by the Constitution, prejudice may be presumed.’” 

904 F.3d at 652 (quoting Garcia-Flores, 17 I. & N. Dec. at 

329). We therefore presume that Perez Cruz was prejudiced 

in his removal proceedings by the ICE agents’ decision to 

detain and question him without individualized reasonable 

suspicion.11 Because the agents violated 8 C.F.R. 

§ 287.8(b)(2), Perez Cruz is entitled to suppression of the 

evidence gathered as a result of that violation. See id. at 653.

Finally, Perez Cruz contends that, if suppression is 

warranted, his removal proceedings should be terminated 

without prejudice. We agree. This court has recognized that 

where evidence of alienage is suppressed and “the 

government did not introduce any other evidence tending to 

show . . . alienage,” termination of the proceedings is 

warranted. Lopez-Rodriguez, 536 F.3d at 1019. Here, the 

government has not offered any other evidence of Perez 

Cruz’s alienage beyond the Form I-213 and his birth 

certificate—fruits of the regulatory violation described 

above. We thus conclude that the removal proceedings 

 11 Even if prejudice were not presumed, it is quite apparent that the 

ICE agents’ improper detention of Perez Cruz “harmed [his] interests in 

such a way as to affect potentially the outcome of [his] deportation 

proceedings,” thereby prejudicing him. Calderon-Medina, 591 F.2d 

at 532. As we explain in the text, without the contested evidence, there 

is no basis in the record for determining Perez Cruz’s alienage.
PEREZ CRUZ V. BARR 31

against Perez Cruz should be terminated without prejudice. 

See id.

IV

The Summers line of cases does not justify using the 

execution of a search warrant for documents to “target” for 

detention, interrogation, and arrest busloads of people who 

could not otherwise be detained. The detentions, we 

conclude, violated an ICE regulation (as well as the Fourth 

Amendment). In light of that regulatory violation, we grant 

Perez Cruz’s petition for review and remand to the BIA with 

instructions to dismiss his removal proceedings without 

prejudice.

PETITION GRANTED; REVERSED and 

REMANDED with instructions.