I.

On November 25, 1990, brothers Juan Maria and Francisco Maria Mota were selling hot corn-on-the-cob from a shopping cart in Santa Ana, California. Officers Haynes and Carillo of the Santa Ana Police Department approached Juan Mota, and asked whether the corn cart was his. He told the officers that he ran the cart with his brother. Francisco Mota then approached and identified himself. The officers asked the brothers whether they had a business license to operate the cart. They admitted that they did not have a license, and the officers arrested and handcuffed them for operating without a valid business license in violation of Santa Ana Municipal Code § 21-6. The officers searched the brothers, and found 41 counterfeit twenty-dollar bills in their pockets.

The Motas were then taken to the Santa Ana police station, cited for operating a business without a license, and detained until Secret Service agents arrived to question them regarding the counterfeit money. Both appellants made incriminating statements at that time, and were subsequently charged with possession of counterfeit Federal Reserve notes in violation of 18 U.S.C. § 472 .

In January, 1991, appellants joined in a motion to suppress the evidence seized and statements taken, arguing that the officers lacked probable cause to arrest, that the arrests were a pretext to allow the officers to conduct unlawful searches, and that the officers lacked authority under California law to arrest the appellants for a mere criminal infraction. The district court denied the motion to suppress on January 28, 1991, granted a motion for reconsideration, and then denied the motion to suppress for a second time on February 5, 1991. The district court found that the officers had probable cause to arrest the appellants, that the search was valid as a search incident to the arrest in order to look for evidence, and finally that the arrest was not a mere pretext to search for evidence of the crime of possession of counterfeit money.

Following the second denial of their motions to suppress, appellants entered pleas of guilty, conditioned upon their right to seek review in this court of the district court’s denial of their motions to suppress. We now reverse.

II.

Appellants argue that the Santa Ana police officers arrested them for oper *1386 ating without a valid business license as a pretext to allow them to search for evidence of counterfeit currency. “[A]n arrest may not be used as a pretext to search for evidence without a search warrant where one would ordinarily be required under the Fourth Amendment.” Williams v. United States, 418 F.2d 159, 161 (9th Cir.1969), aff 'd, 401 U.S. 646 , 91 S.Ct. 1148 , 28 L.Ed.2d 388 (1971). A search is pretextual when “the motivation or primary purpose of the arresting officers” is to arrest a defendant “for a minor offense so as to allow police to search for evidence of some other unrelated offense for which police lack probable cause to arrest or search.” United States v. Smith, 802 F.2d 1119, 1124 (9th Cir.1986). We review for clear error the district court’s determination regarding the arresting officers’ motives. United States v. Espinosa, 827 F.2d 604, 609 (9th Cir.1987), cert. denied, 485 U.S. 968 , 108 S.Ct. 1243 , 99 L.Ed.2d 441 (1988).

Although the arresting officer did acknowledge that he was aware of counterfeit bills in the area, the district court credited his testimony that appellants were arrested exclusively as a result of their municipal code infraction of operating without a business license. Appellants argue that this finding was erroneous based solely on the fact that they were arrested for a minor infraction, and the subsequent search uncovered evidence of their commission of a felony. While these circumstances might raise a suspicion of pretext, they do not suffice to demonstrate that the district court clearly erred in its factual finding. See United States v. Huffhines, 967 F.2d 314, 317-18 (9th Cir.1992) (arresting officer’s failure to follow ordinary cite and release procedure insufficient to show clear error in district court’s conclusion that arrest was not pretext to search).

III.

Appellants next contend that the search which uncovered the counterfeit bills was unconstitutional. The government defends the search as a valid search incident to the arrest of the appellants. In appraising the validity of a search incident to arrest, we “review de novo the application of established facts to legal standards.” United States v. Turner, 926 F.2d 883, 887 (9th Cir.), cert. denied, — U.S. —, 112 S.Ct. 103 , 116 L.Ed.2d 73 (1991).

It is clear beyond question that a search incident to a lawful custodial arrest is an exception to the warrant requirement of the Fourth Amendment:

United States v. Robinson, 414 U.S. 218, 235 , 94 S.Ct. 467, 477 , 38 L.Ed.2d 427 (1973). The Robinson court, however, declined to discuss the authority to search arising from an arrest “where [normally] the officer would simply issue a notice of violation and allow the offender to proceed.” Id. at 236 n. 6, 94 S.Ct. at 477 n. 6.

We have since held that, absent probable cause to search, a “custodial arrest” is “necessary to support a search incident to arrest.” United States v. Parr, 843 F.2d 1228, 1230 (9th Cir.1988). In Parr , we reversed the defendant’s conviction, finding that he had not been taken into custody, and that therefore he could not be searched incident to arrest.

We must therefore determine, as an initial matter, whether appellants were “subjected to treatment that rendered] [them] ‘in custody’ ” at the time of the search. Parr, 843 F.2d at 1231 . We believe that the Motas clearly had been taken *1387 into custody. When searched, appellants had been handcuffed and notified that they were under arrest. [Tr. 2/5/91 at 16, 23]. Viewed from the perspective of the Motas, a reasonable person would have undoubtedly felt that he was under arrest. See United States v. Mejia, 953 F.2d 461, 467 (9th Cir.1991), cert. denied, — U.S. —, 112 S.Ct. 1983 , 118 L.Ed.2d 581 (1992). Thus, the search was clearly incident to a custodial arrest.

Our inquiry is not complete, however, for under Robinson , the arrest must be both custodial and lawful to support a search incident to that arrest. Consequently, we must next determine what standard is to be used in assessing the lawfulness of the custodial arrest.

We held in United States v. Chavez-Vernaza, 844 F.2d 1368 (9th Cir.1987), that application of the exclusionary rule in federal court should not be made to turn on state law. Id. at 1373 . Instead, we concluded that the application of the exclusionary rule in federal court proceedings is a matter of federal law, and “evidence seized in compliance with federal law is admissible without regard to state law.” Id. at 1374 .

This does not necessarily mean, however, that state law will always be irrelevant in assessing the legality of a seizure as a matter of federal law. As we subsequently observed in United States v. Wanless, 882 F.2d 1459 (9th Cir.1989), federal law may require that searches and seizures be conducted in accordance with state law. Id. at 1464 . In Wanless , for example, we noted that under federal law, inventory searches “must be conducted in accordance with the official procedures of the relevant state or local police department.” Id. Thus, in evaluating the appropriateness of excluding evidence seized by state officials pursuant to an inventory search, federal courts must necessarily consider the lawfulness of the search as a matter of state law.

Similarly, whether an officer is authorized to make an arrest will ordinarily depend “in the first instance, on state law.” Michigan v. DeFillippo, 443 U.S. 31, 36 , 99 S.Ct. 2627, 2631 , 61 L.Ed.2d 343 (1979). We have held in the context of a suit brought under 42 U.S.C. § 1983 , that state law governing an arrest is irrelevant to determining whether the arrest deprived an individual of rights secured by the federal constitution or a federal statute. See Barry v. Fowler, 902 F.2d 770, 772 (9th Cir.1990). But here the government would have us sanction an otherwise unconstitutional search on the basis of an arrest which is illegal as a matter of state law. Precedent forecloses such a holding, however, for it is clear that state law governing arrests is relevant to assessing the constitutionality of a search incident to that arrest. In United States v. Di Re, 332 U.S. 581 , 68 S.Ct. 222 , 92 L.Ed. 210 (1948), for example, the Supreme Court reversed a conviction based on evidence seized during a search incident to arrest. The Court held that the search incident to arrest was unlawful since the arresting officers had no authority to arrest under state law.

We note that other circuits have questioned the continued validity of Di Re as precedent in light of the Supreme Court’s decisions in Elkins v. United States, 364 U.S. 206 , 80 S.Ct. 1437 , 4 L.Ed.2d 1669 (1960), and United States v. Ross, 456 U.S. 798 , 102 S.Ct. 2157 , 72 L.Ed.2d 572 (1982). See United States v. Walker, 960 F.2d 409 (5th Cir.1992); United States v. Mahoney, 712 F.2d 956 (5th Cir.1983), cert. denied, 468 U.S. 1220 , 104 S.Ct. 3590 , 82 L.Ed.2d 887 (1984); United States v. Miller, 452 F.2d 731 (10th Cir.1971), cert. denied, 407 U.S. 926 , 92 S.Ct. 2466 , 32 L.Ed.2d 813 (1972). The Tenth Circuit read Elkins as overruling Di Re and requiring that federal courts look only to federal law in determining the legality of an arrest. Miller, 452 F.2d at 733 . This interpretation of Elkins overlooks subsequent Supreme Court authority, however, which reaffirmed the relevance of state law to the legality of an arrest as a matter of federal law. See Ker v. California, 374 U.S. 23, 37 , 83 S.Ct. 1623, 1632 , 10 L.Ed.2d 726 (1963). In addition, we believe the Tenth Circuit has read Elkins too broadly. The issue which the Supreme Court addressed in Elkins was whether “articles obtained as the result of an unreasonable search and seizure by state officers, without involvement of federal officers, [may] be introduced in evi *1388 dence against a defendant over his timely objection in a federal criminal trial.” 364 U.S. at 208 , 80 S.Ct. at 1439 . Elkins thus re-examined the “silver platter” doctrine, which allowed the introduction of evidence illegally seized by state authorities so long as federal authorities were uninvolved in the seizure. Id. at 208 & n. 2, 80 S.Ct. at 1439 & n. 2. The Court concluded that:

Id. at 223 , 80 S.Ct. at 1447 . This observation, of course, fails to address the relevance of state law to the reasonableness of an arrest. And while it is true that the Court instructed that “[t]he test is one of federal law,” id. at 224 , 80 S.Ct. at 1447 , our decision in Wanless illustrates that federal law may require state authorities to conform to state law. 882 F.2d at 1464 .

The Fifth Circuit in Mahoney and Walker has also found state law irrelevant to whether an arrest is legal as a matter of federal law. In United States v. Garcia, 676 F.2d 1086 (5th Cir.1982), the Fifth Circuit applied state law in determining that the defendant’s arrest had been illegal. Id. at 1094 . The Garcia court then assessed the admissibility of the evidence seized subsequent to the arrest under the state’s exclusionary rule, and concluded that under Texas law the evidence should have been excluded. Id. The Supreme Court granted certiorari, summarily vacating the judgment, and remanding the case for further consideration in light of Ross. United States v. Garcia, 462 U.S. 1127 , 103 S.Ct. 3105 , 77 L.Ed.2d 1360 (1983). The Fifth Circuit concluded, we believe correctly, that by remanding Garcia in light of Ross , the Supreme Court intended to instruct the Fifth Circuit “that the admissibility of evidence depends on the legality of the search and seizure under federal law.” Walker, 960 F.2d at 415 (quoting Mahoney, 712 F.2d at 959 ). We disagree, however, that Supreme Court’s action can be interpreted as foreclosing any consideration of state law in determining the legality of an arrest. In other words, we construe the Supreme Court’s action as a rejection of Garcia’s reliance on state law governing the exclusion of evidence from court. Ross in no way established a federal law governing the legality of arrests, however, and the Supreme Court has subsequently indicated that state law governing an arrest is relevant to the constitutional analysis of the legality of that arrest.

In Welsh v. Wisconsin, 466 U.S. 740 , 104 S.Ct. 2091 , 80 L.Ed.2d 732 (1984), for instance, the Court addressed the circumstances under which the Fourth Amendment prohibits police from making a warrantless arrest. Id. at 742 , 104 S.Ct. at 2093. The Court held that the reasonableness of such an arrest is to be determined in light of the state’s assessment of the gravity of the offense justifying the arrest, as expressed by the state’s classification of the offense. Id. at 753-754, 104 S.Ct. at 2099-2100. We similarly hold that in evaluating a custodial arrest executed by state officials, federal courts must determine the reasonableness of the arrest in reference to state law governing the arrest.

In this case, the State of California has abjured the authority to execute custodial arrests for offenses so minor that they are designated as infractions. California Penal Code § 836 (1985) enables a peace officer to “without a warrant, arrest a person ... [w]henever he has reasonable cause to believe that the person to be arrested has committed a public offense in his presence.” The scope of the arrest is restricted, however, by California Penal Code § 853.5 (1985), which provides that:

Thus, under California law, the arresting officers were without legal authority to take appellants into custody for the infraction of operating without a valid business *1389 license in violation of Santa Ana Municipal Code § 21-6. See also People v. Williams, 3 Cal.App. 4th 1100 , 1105 n. 1, 5 Cal. Rptr.2d 59 , 61 n. 1 (1992) (“Only if the arrestee refuses to present written identification or to sign the written promise to appear may he be taken into custody” under CahPenal Code § 853.5).

Given the state’s expression of disinterest in allowing warrantless arrests for mere infractions, we conclude that a custodial arrest for such an infraction is unreasonable, and thus unlawful, under the Fourth Amendment. Since the custodial arrest of appellants was invalid, the search should not have been exempted from the warrant requirement of the Fourth Amendment as a search incident to lawful arrest. Absent some other basis justifying the search, the evidence seized from appellants was unlawfully obtained, and should have been suppressed.

Accordingly, appellants’ convictions are REVERSED. The case is REMANDED for proceedings consistent with this opinion.