Willа Johnson attempted to enter the United States with heroin concealed in a suitcase. A customs inspector discovered the heroin during a search of Ms. Johnson’s luggage. After her arrest and subsequent *1289 indictment, Ms. Johnson pleaded guilty to possessing with the intent to distribute approximately 1470.6 grams of heroin in violation of 21 U.S.C. § 841(a)(1), but preserved her right to appeal the district court’s denial of her motion tо suppress the heroin. See Fed.R.Crim.P. 11(a)(2). Because the district court properly denied Ms. Johnson’s motion to suppress, we affirm the district court’s judgment.
I
BACKGROUND
On May 14, 1991, Ms. Johnson arrived at O’Hare International Airport on a direct flight from the Philippines. Because she had declared over $400 in foreign purchases, she was referred to secondary customs for a calculation of the duty that she owed. She had in her рossession four pieces of luggage: three soft-sided suitcases and one large, hard-sided suitcase.
Ms. Johnson proceeded to secondary customs where she encountered Inspector Larry Digiannantonio of the United States Customs Service. Inspector Digiannanto-nio asked Ms. Johnson some questions about her trip and learned that (i) Ms. Johnson had visited the Philippines; (ii) the purposе of her trip was to visit her grandparents; (iii) she had stayed with her grandparents; (iv) she had purchased $1000 worth of new clothes in the Philippines; and (v) she worked in the United States as a secretary at various hospitals, but she was unable to specify which hospitals. Ms. Johnson showed Inspector Digi-annantonio her airline ticket and her passport. He observed that the passport had been newly issued the month before, that Ms. Johnson had paid for the ticket in cash on the day of her departure, and that her trip had lasted only five days.
Inspector Digiannantonio began to inspect Ms. Johnson’s luggage. In her carry-on luggage, he found a receipt for a hotel in the Philippines. He questioned Ms. Johnson about her earlier statement that she had stayed with her grandparents, and she replied that although shе had checked into a hotel, she still had stayed overnight with her grandparents. Inspector Digian-nantonio next inspected the large, hard-sided suitcase, which appeared to be new. Ms. Johnson told him that she had purchased the suitcase in the Philippines. When Inspector Digiannantonio asked her how much she had paid for the suitcase, Ms. Johnson hesitantly replied that her grandparents had рurchased the suitcase for her.
At Inspector Digiannantonio’s request, Ms. Johnson opened the hard-sided suitcase. The contents consisted entirely of brand new clothes. Inspector Digiannanto-nio performed a “scratch test” on the top part of the suitcase by placing one hand on the outer shell, his other hand on the inner shell, and scratching the outer shell to create a vibrаtion. The absence of a vibration would have been abnormal and would have suggested that there was contraband in the shell. The top part of the suitcase passed the scratch test. Next, Inspector Digian-nantonio performed a “flex test” on the top part of Ms. Johnson’s suitcase, using his hands to move the shell to test its flexibility. A lack of flexibility would have suggested the presence of contraband in the shell. The top part of Ms. Johnson’s suitcase passed the flex test. Finally, Inspector Digiannantonio determined that the top of the suitcase was of normal weight, which suggested that there was no contraband hidden in the shell.
The bottom part of Ms. Johnson’s suitcase, however, was suspicious. It was much heavier than the top part of the suitcase and it failed both the flex and scratch tеsts. Believing that the shell might contain contraband, Inspector Digiannantonio took the empty suitcase to an X-ray machine that was located a few feet away. The X-ray revealed a mass in the shell. Inside the mass could be seen outlines of what appeared to be small rectangular packages. Inspector Digiannantonio directed two customs agents to escort Ms. Johnson to a back room, which they did. He then took the suitcase into a tool room and removed the nylon cloth lining from the bottom part of the suitcase. He could see through a tiny hole in the shell that something was inside that was not the *1290 same color as the suitcase. Suspecting that there was a false shell in the suitcase, he removed the shell, whereupon he smelled mothballs (but saw none) and fоund a package that was approximately three feet long, two feet wide, and one-quarter inch thick. Inside the package was white powder, which field-tested positive for heroin. Thereafter, inspectors strip-searched Ms. Johnson and recovered $900 in cash.
A federal grand jury returned a two-count indictment against Ms. Johnson. The only count relevant to this appeal is Count One, whiсh charged Ms. Johnson with possessing with the intent to distribute approximately 1470.6 grams of heroin in violation of 21 U.S.C. § 841(a)(1). Ms. Johnson sought to suppress the heroin found during the search at the airport. She argued that both the search of her luggage and her detention ran afoul of the Fourth Amendment. After holding an evi-dentiary hearing, the district court denied Ms. Johnson’s motion to suppress. Ms. Johnson subsequently entered a conditionаl plea of guilty, preserving her right to appeal the district court’s denial of her motion. The district court sentenced Ms. Johnson to ten years in prison, to be followed by five years of supervised release. This appeal followed.
II
DISCUSSION
The issue presented by this appeal is whether the search of Ms. Johnson’s luggage and her coterminous detention were “unreasonable” as that term is used in thе Fourth Amendment.
1
The district court concluded that the search and detention constituted no more than a routine border inspection and, as such, were reasonable. The court also stated that, even if this procedure could not be considered routine, it did not contravene the Fourth Amendment because the customs inspectors had an adequate basis of suspicion to conduсt the search and to detain Ms. Johnson before, during, and after the search. Accordingly, the district court denied Ms. Johnson’s motion to suppress the heroin. A district court’s denial of a motion to suppress evidence is reviewed deferentially because the district court had the opportunity to hear the testimony and observe the demeanor of the witnesses who testified at the hearing.
United States v. Edwards,
A.
The search and detention in this case occurred át O’Hare International Airport, after Ms. Johnson arrived on a nonstop international flight. The airport therefore was functionally equivalent to an international border.
United States ¶. Dorsey,
Customs officials have plenary authority to conduct
routine
searches and seizures at the border, even without probable cause or a warrant, in оrder to regulate the collection of duties and to prevent the introduction of contraband into this country.
United States v. Montoya de Hernandez,
When a border search and sеizure becomes nonroutine, a customs official needs reasonable suspicion to justify it.
Montoya de Hernandez,
In determining whether an inspection made at the border was routine, courts have focused on the degree of intrusion into a border entrant’s legitimate expectations of privacy.
Braks,
B.
Ms. Johnson disputes the district court’s determination that she was subject to a routine border inspection and not something more intrusive. She submits that the actions of Inspector Digiannantonio and the other officials who , led her through customs at O’Hare International Airport exceeded the limits of a routine border inspection. But application of the above precepts to the facts of this case lead us to conclude that the district court did not commit clear error in finding that Ms. Johnson was subject to no more than a routine border inspection.
1.
Ms. Johnson devotes a good portion of her brief to the argument that her detention by Inspector Digiannantonio prior to the search of her suitcase ran afoul of the Fourth Amendment because it was not supported by articulable suspicion. She contends that, to justify detaining her, Inspector Digiannantonio first had to suspect reasonably that Ms. Johnson was smuggling contraband into the country and, based on what he knew when he detained her (that Ms. Johnson worked in the United States as a secretary at unspecified hospitals, that she had returned from the Philippines after a five-day pleasure trip, that she had purchased her ticket in cash on the date of her departure, and that she had dеclared $1000 in foreign purchases), he lacked this requisite level of suspicion. In short, Ms. Johnson maintains that, even before he saw the suitcase in which he ultimately found the heroin, Inspector Digiannantonio detained her because he was convinced that she was smuggling contraband into the country. The district court concluded that Ms. Johnson’s detention was part of the routine border inspection. We agree. Indeed, Ms. Johnson’s emphasis on her detention obscures the true issue in this case, whether the search of her luggage was reasonable. We now turn to that issue.
2.
Inspector Digiannantonio’s search of Ms. Johnson’s suitcase was minimally intrusive and was well within the scope of what is considered routine. Inspector Digi-annantonio first removed the contents of Ms. Johnson’s suitcase. A customs official might have to rummage though any border entrant’s luggage to ascertain whether all items have been declared properly. Such a minimal intrusion is a routine task. Removing the contents of a border entrant’s luggage is only slightly more invasive and must also be considered routine.
Inspector Digiannantonio’s next step was to execute the “scratch test,” “flex test,” and “weight test” on the top and bottom parts of Ms. Johnson’s suitcase. These procedures also were minimally intrusive. They required only a few minutes of Ms. Johnson’s time, did not harm the suitcase, and involved no harm or indignity to Ms. Johnson. Indeed, these tests were so unobtrusive that Ms. Johnson did not notice that Inspector Digiannantonio was performing them, even though she was standing only a few feet away. Moreover, Inspector Digi-annantonio had the obligation аs an agent •of the United States Customs Service to make sure that Ms. Johnson was not smuggling contraband into the country. He tes *1293 tified that he performs all three tests on the luggage of all border entrants in order to meet that obligation. 4 These three tests, which are nothing more than a visual and manual determination that the luggage of border entrants carries no contraband, are within the scope of а routine border inspection.
After Ms. Johnson’s suitcase had failed the scratch, flex, and weight tests, Inspector Digiannantonio subjected the suitcase to an X-ray examination. Again, this procedure took only a few minutes and was minimally intrusive, causing no harm to the suitcase and no embarrassment or indignity to Ms. Johnson. No doubt thousands of airport users subject their luggage to the same procedure eаch day; the machine that was used to X-ray Ms. Johnson’s suitcase was the type that is used in airports across the country. Ms. Johnson could not have reasonably expected that her suitcase would pass through customs without being subjected to an X-ray examination.
Moreover, even if the border search became nonroutine when Inspector Digian-nantonio subjected Ms. Johnson’s suitcase to an X-ray examination (a proposition that we believe lacks merit) Inspector Digian-nantonio had an adequate quantum of suspicion to justify the X-ray examination. As we have already noted, in
Montoya de Hernandez,
the Supreme Court held that the detention of a traveler at the border, beyond the scope of a routine border inspection, must be justified by a “reasonable suspicion” that the travelеr is smuggling contraband into the country.
After the X-ray of Ms. Johnson’s suitcase revealed the presеnce of a foreign object in the suitcase’s shell, Inspector Digiannantonio instructed two fellow customs inspectors to take Ms. Johnson to a nearby holding room while he took the suitcase to a tool room. There he removed the inner shell, which revealed a package that covered the bottom of the suitcase. This package was ultimately determined to contain heroin. Even if this search could no longer be characterized as routine when Inspector Digiannantonio took Ms. Johnson’s suitcase to the tool room, an adequate degree of suspicion existed to justify a nonroutine search of the suitcase. Moreover, removal of the inner shell of her suitcase was justified on the basis of the newly acquired information. Ms. Johnson cannot arguе *1294 meritoriously that, once the X-ray examination revealed the presence of a foreign object in the shell of her suitcase, Inspector Digiannantonio was not justified in taking steps to determine whether the foreign object was contraband.
3.
Likewise, there was an adequate basis for the customs officials to detain Ms. Johnson in a holding room while Inspector Digiannantonio conduсted his search and completed a field test on the substance found in the shell of the suitcase. The detention of a border entrant must be reasonably related in scope to the circumstances justifying it.
Montoya de Hernandez,
Conclusion
The district court, in denying Ms. Johnson’s motion to suppress the heroin that was found in her suitcase, committed no error. We therefore affirm thе district court’s judgment.
Affirmed.
Notes
. The applicable Customs Regulation provides that “[a]ll persons, baggage, and merchandise arriving in the Customs territory of the United States from places outside thereof are liable to inspection and search by a Customs officer.” 19 C.F.R. § 162.6 (1990).
.
See Thirty-seven Photographs,
. "The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated_" U.S. Const, amend. IV.
. Ms. Johnson maintains that Inspector Digian-nantonio’s testimony that he performs the scratch test, flex test, and weight test on the luggage of every border entrant that he encounters is incredible given the volume of travelers coming through customs at O’Hare International Airport. Ms. Johnson contends that the implausibility of this testimony is strong evidence that Inspector Digiannantonio conducted a non-routine search of her luggage. That Inspector Digiannantonio might not inspect every border entrant's luggage in the same manner is not ground for characterizing as nonroutine the search of Ms. Johnson’s luggage. We have already acknowledged that a customs official may conduct routine searches on a random basis and not run afoul of the Fourth Amendment.
See Braks,
