Petitioner Pedro Cervantes-Cuevas seeks review of the decision of an immigration judge, affirmed by the Board of Immigration Appeals, finding petitioner deportable under 8 U.S.C. § 1251(a)(2) for entry without inspection. This court has jurisdiction under 8 U.S.C. § 1105a(a). Reversal is sought on the ground that the immigration judge erred in denying petitioner’s motion to suppress evidence of the statements he made following his detention by agents of the United States Border Patrol. We affirm.
I. PERTINENT FACTS
At the time of the hearing before the immigration judge, petitioner was a 38 year-old married male alien, who was a citizen of Mexico. He entered the United States from Mexico during April of 1977, without submitting himself for inspection.
Petitioner was detained and subsequently arrested on March 18, 1982. Prior to being detained, petitioner was driving on Highway 12, near Wapato, Washington during a time when the United States Border Patrol was engaged in an operation checking establishments and places where undocumented aliens were likely to congregate. This operation was based upon reports received from informants, Border Patrol agents, and local law enforcement officers that the Wapato area of the Yakima Valley was “highly populated” with undocumented aliens from Mexico. In addition, in the course of their investigation, the Border Patrol agents had observed that when officers in marked vehicles approached housing which contained illegal aliens, some persons in the vicinity would leave in motor vehicles. Information concerning the fact that such persons had departed was relayed over the radio by surveillance officers in unmarked cars to agents who would detain persons who stopped their cars and fled on foot or appeared to speed up after passing Border Patrol vehicles. Approximately 500 undocumented aliens were arrested by the Border Patrol in the Yakima Valley during the week that petitioner was detained and then arrested.
The uncontradicted evidence showed that as the petitioner approached a Border Patrol vehicle parked next to a pick-up truck, he slowed to ten miles per hour, and then speeded up to forty-five miles per hour. Petitioner was followed by a Border Patrol vehicle. He stopped his car when the flashing lights were turned on.
After the petitioner was stopped, he was asked to show any documents establishing that he was lawfully in the United States. Instead of complying with this request, the petitioner handed the agents a G-28 Notice of Appearance of Attorney. The petitioner was then arrested. In a later conversation with an agent of the Border Patrol, the petitioner stated that he originally entered the United States from Mexico without inspection. These statements were included in a Form 1-213 report. >
In his motion to suppress his statements, petitioner contended that the detention and arrest was unlawful because of the “lack of specific, articulable facts supporting respondent’s arrest, interrogation and confinement in jail pursuant to U.S. v. Brignoni-Ponce, 422 U.S. 873, 878, [95 S.Ct. 2574, 2578, 45 L.Ed.2d 607] (1975).”
Petitioner made no contention before the immigration judge that the agent’s conduct was “egregious” or that his statements were coerced, made under duress, or were otherwise involuntary.
Petitioner submitted an affidavit in support of his motion to suppress the statements obtained following his arrest containing the following allegations: As he was driving to work on Highway 12 at 6:45 a.m. on March 18, 1982, petitioner saw a stalled pickup truck on the roadway. He slowed his vehicle to 10 miles per hour to go around the truck. He observed a Border Patrol vehicle behind the pick-up truck. He did not turn his head to look at the Border Patrol vehicle. He resumed his speed of forty-five miles per hour.
*709The immigration judge concluded that an experienced Border Patrol agent would reasonably suspect that the petitioner was an alien based on the following facts: (1) other agents and local law enforcement officers had reported through official channels that many undocumented aliens were leaving the buildings in the area of the arrest; (2) some aliens were fleeing their housing in the area in automobiles as others were approached or being questioned; and (3) the petitioner’s car slowed down and then increased its speed as it drove away after observing a Border Patrol vehicle stopped behind a pick-up truck. Because it was his view that the record contained sufficient articulable facts to warrant stopping the petitioner to determine whether he was an alien and if he was lawfully in the United States, the immigration judge concluded that the arrest was lawful.
Petitioner filed a timely appeal with the Board of Immigration Appeals (hereinafter the Board). Petitioner’s notice of appeal to the Board stated that the arrest was illegal in that the Border Patrol agents had violated the decision of the Supreme Court in Brignoni-Ponce, 422 U.S. 873, 95 S.Ct. 2574, 45 L.Ed.2d 607 (1975). He did not contend that the conduct of the Border Patrol agents was “egregious” or that his statement was made involuntarily. The Board concluded that the arrest was lawful because the record contained sufficient articulable facts to support a reasonable suspicion that the petitioner was an undocumented alien prior to his detention, as required by Brignoni-Ponce. Petitioner’s appeal was dismissed by the Board.
II. ISSUES ON APPEAL
The issues presented by this appeal can be summarized as follows:
One. Prior to directing petitioner to stop his vehicle, were the Border Patrol agents aware of specific, articulable facts that warranted a reasonable suspicion that the car contained aliens illegally residing in the United States?
Two. Does the exclusionary rule apply to civil deportation proceedings where the record shows that there were no specific articulable facts to justify a reasonable suspicion, prior to detention, that the petitioner was an alien illegally in this country?
Three. Should the decision of the Supreme Court in INS v. Lopez-Mendoza, 468 U.S. 1032, 104 S.Ct. 3479, 82 L.Ed.2d 778 (1984) be applied retroactively to conduct of Border Patrol agents which occurred prior to its effective date?
Four. Was the probative value of the evidence obtained from the petitioner undermined by “egregious” conduct of the arresting officers?
A. Presence of Articulable Facts and Reasonable Suspicion
The question of the appropriate standard of review applicable to the Board’s finding that the Border Patrol agent had a founded suspicion for stopping petitioner is unclear in this circuit. United States v. Magana, 769 F.2d 549, 550-51 (9th Cir.1985). Like the panel in Magana, however, we need not decide whether findings of founded suspicion are reviewable under the clearly erroneous standard or receive de novo review; under either standard of review, petitioner’s detention was based upon a founded suspicion of unlawful activity. See id. at 551.
Petitioner argues that the basis for the Border Patrol agent’s belief that he was an illegal alien — his physical appearance and the fact that he slowed down upon approaching the pick-up truck and then continued on at a speed of forty-five miles per hour — was insufficient to justify his detention under Brignoni-Ponce. Although the facts selected by petitioner, standing alone, may not meet the Supreme Court’s standards for a reasonable detention, see Nicacio v. INS, 768 F.2d 1133, 1137 (9th Cir.1985) (“Hispanic-looking appearance and presence in an area where illegal aliens frequently travel are not enough to justify a stop to interrogate the occupants of a vehicle”), resolution of this question is unnecessary. Petitioner has ig*710nored the facts articulated by the Border Patrol agent which were known to him prior to the detention. The record shows that at the time of petitioner’s detention and arrest, agents of the Border Patrol were engaged in approaching and interrogating persons who resided in buildings in the Wapato area based on information from various sources, including official channels, that the area was “highly populated” by undocumented aliens from Mexico. The arresting officers were also aware that some of these aliens would flee from their housing units in automobiles to avoid interrogation by the officers engaged in their ongoing investigation, and that 500 undocumented aliens had been seized in that area during that week.
It was in light of these additional circumstances that the immigration judge and the Board concluded that the fact that a person who appeared to be an alien slowed down to ten miles an hour and then accelerated to a higher speed after passing a border patrol vehicle, constituted a sufficient objective basis for a reasonable suspicion that the car contained undocumented aliens. As the Supreme Court stated in Brignoni-Ponce, the test for lawful vehicle stops by roving patrols is awareness of “specific articulable facts, together with rational inferences from those facts, that reasonably warrant suspicion that the vehicles contain aliens who may be illegally in the country.” 422 U.S. at 884, 95 S.Ct. at 2582 (footnote omitted) (emphasis added). We have noted that “[a]n agent’s experience might make a situation suspicious to him which to the untrained or experienced eye would pass unnoticed or seem innocent.” Nicacio v. INS, 768 F.2d at 1138-39; see also Magana, 769 F.2d at 553 (trained officers entitled to combine objective facts with permissible deductions to form legitimate basis for suspicion). In the instant case, the arresting agent was entitled to draw the inference that petitioner was an illegal alien fleeing from a housing unit in the Wapato area in order to avoid interrogation.
B. Application of Exclusionary Rule to An Unlawful Arrest
We need not decide, however, if knowledge of these additional facts by an experienced Border Patrol agent meets the strictures of Brignoni-Ponce. We recently held in Benitez-Mendez v. INS, 760 F.2d 907 (9th Cir.1983) that in light of the Supreme Court’s decision in INS v. Lopez-Mendoza, “even though ... petitioner’s arrest violated the Fourth Amendment, the information obtained as the result of the arrest (petitioner’s statements on Form I-213) was admissible at his deportation hearing.” 760 F.2d at 910. Thus, our holding in Benitez-Mendez compels us to rule in the instant matter that petitioner’s statements were admissible even if we assume that the detention of the petitioner was not based on specific articulable facts or reasonable suspicion.
C. Retroactivity of INS v. Lopez-Mendoza
Petitioner apparently argues that the Supreme Court’s decision in Lopez-Mendoza cannot be applied retroactively. This argument is meritless. In BenitezMendez we applied the Supreme Court’s decision in Lopez-Mendoza (decided July 5, 1985) to an arrest that occurred on April 13, 1981, Benitez-Mendez, 760 F.2d at 908-10.
D. Alleged Egregious Conduct.
Petitioner asserts that “an egregious violation of the Brignoni standards has occurred in that no specific articulable facts have been proven to justify petitioner’s detention.” Petitioner offers no authority for the novel proposition that the mere failure to articulate specific facts to justify a detention is “egregious” conduct requiring suppression of evidence in a civil deportation proceeding. It is quite true that the Supreme Court left open the question whether the exclusionary rule would apply to “egregious violations of Fourth Amendment or other liberties that might transgress notions of fundamental fairness and undermine the probative value of the evi*711dence obtained.” Lopez-Mendoza, 104 S.Ct. at 3490 (emphasis added). Petitioner has neither argued nor attempted to demonstrate that the conduct of the Border Patrol agents in this matter in any way undermined the probative value of petitioner’s statements. No evidence was offered that the statements were made involuntarily, or were the product of duress or coercion. In Lopez-Mendoza, the Supreme Court held that the exclusionary rule does not apply in civil deportation proceedings to evidence gathered in connection with a “peaceful arrest” which violated the Fourth Amendment. Id. at 3490-91.
In the absence of some proof casting doubt on the probative value of voluntary statements following an illegal detention, evidence that the arrest was unlawful does not affect the admissibility of an undocumented alien’s statements.
CONCLUSION
Petitioner has failed to demonstrate that his statements were obtained by Border Patrol agents in a manner which casts doubt on their probative value. Accordingly, his post-detention statements were admissible. The motion to suppress was properly denied because the exclusionary rule is inapplicable in civil deportation proceedings in the absence of any showing that the officer’s conduct would undermine the credibility of the challenged evidence.
AFFIRMED.