UNITED STATES OF AMERICA, PETITIONER V. ANDREW SOKOLOW

   No. 87-1295

   In the Supreme Court of the United States

   October Term, 1987

   The Solicitor General, on behalf of the United States, petitions
for a writ of certiorari to review the judgment of the United States
Court of Appeals for the Ninth Circuit in this case.

   Petition for a Writ of Certiorari to the United States Court of
Appeals for the Ninth Circuit

            TABLE OF CONTENTS
   Question Presented
   Opinions below
   Jurisdiction
   Constitutional provision involved
   Statement
   Reasons for granting the petition
   Conclusion

                            OPINIONS BELOW

   The opinion of the court of appeals on rehearing (App. 1a-33a) is
reported at 831 F.2d 1413.  The initial opinion of the court of
appeals, as amended (App. 34a-46a), is reported at 808 F.2d 1366.  The
other orders and opinions in the case, including the order of the
court of appeals remanding the case for additional factual findings
(App. 50a-51a);  the opinion of the district court on remand from the
court of appeals (App. 47a-49a);  the order and opinion of the
district court denying respondent's motion to suppress (App. 52a-55a);
 and the magistrate's report and recommendation (App. 56a-62a) are
unreported.

                             JURISDICTION

   The judgment of the court of appeals was entered on January 28,
1987.  A petition for rehearing was denied on November 4, 1987 (App.
1a).  On December 30, 1987, Justice O'Connor extended the time within
which to file a petition for a writ of certiorari to and including
February 2, 1988.  /1/ The jurisdiction of this Court is invoked under
28 U.S.C. 1254(1).

                   CONSTITUTIONAL PROVISION INVOLVED

   The Fourth Amendment to the Constitution of the United States
provides in pertinent part:

         The right of the people to be secure in their persons,
      houses, papers, and effects, against unreasonable searches and
      seizures, shall not be violated * * *.

                          QUESTION PRESENTED

   Whether a reasonable suspicion that a person is engaged in
narcotics trafficking can be based on a commonsense analysis of all
the information in the officers' possession, or whether it must be
based on at least one factor that constitutes direct evidence of an
ongoing crime, plus circumstantial evidence that can be considered
only if its significance is verified by empirical or statistical
evidence.

                               STATEMENT

   Following the denial of a motion to suppress evidence in the United
States District Court for the District of Hawaii, respondent entered a
conditional plea of guilty to the charge of possessing cocaine with
the intent to distribute it, in violation of 21 U.S.C. 841(a)(1).  He
was sentenced to five years' imprisonment to be followed by a special
parole term of three years.  The court of appeals reversed by a
divided vote.

   1. On July 22, 1984, respondent approached the United Airlines
ticket counter at the Honolulu airport.  /2/ Respondent appeared to be
roughly 25 years old;  he was wearing a black jumpsuit and a great
deal of gold jewelry;  and he was accompanied by a woman.  He
purchased two round-trip tickets to Miami in the names Andrew Kray and
Janet Norian with an open return.  The price of the tickets was $2100.
 Respondent paid for the tickets with cash from a large roll of $20
bills that he handed to the ticket agent.  The agent counted out
$2100, which depleted the roll by about half, and returned the rest of
the roll to respondent.  Neither respondent nor his companion checked
any luggage, although they had four bags with them.  Upon request,
respondent gave the ticket agent a telephone number.  The agent
noticed that respondent seemed nervous while he was buying the
tickets.  App. 2a, 56a;  9/22/86 Tr. 16-18.

   After respondent left for his flight, the ticket agent told Officer
John McCarthy of the Honolulu Police Department about respondent's
cash purchase of the tickets.  Officer McCarthy, who was a member of
the Department's Airport Task Force, checked the telephone number that
respondent had left with the ticket agent and learned that it was
listed to a "Karl Herman";  McCarthy was unable to find any Hawaii
listing under the name "Andrew Kray." /3/ The ticket agent identified
respondent's voice on a recorded message at the telephone number
respondent had left.  App. 2a-3a, 56a-57a;  9/22/86 Tr. 18-19, 23;
McCarthy Aff. 1.

   Officer McCarthy subsequently learned that respondent and Norian
were scheduled to return to Honolulu on July 25, three days after they
had left.  He also learned that on the way back from Miami, they were
scheduled to make stopovers in Denver and Los Angeles.  On the return
trip from Miami, narcotics agents spotted respondent in a waiting area
at the Los Angeles airport.  They noticed that he "appeared to be very
nervous and was looking all around the waiting area" (9/22/86 Tr. 20).

   Respondent and Norian arrived in Honolulu at about 6:30 p.m. on
July 25.  Respondent was wearing the same black jumpsuit and gold
jewelry that he wore when the trip began.  Once again, he and Norian
had checked no luggage but were carrying four bags.  Upon deplaning in
Honolulu, they walked directly to a street level taxi stand.  The
narcotics officers who had been watching respondent decided to
approach him to examine his identification and airline tickets.  App.
3a, 57a, 10/29/84 Tr. 11;  9/22/86 Tr. 19;  McCarthy Aff. 1.

   At 6:41 p.m., while respondent was waiting for a cab, Drug
Enforcement Administration (DEA) Agent Richard Kempshall displayed his
credentials, took respondent by the arm, and guided him back onto the
sidewald.  App. 47a, 57a;  10/29/84 Tr. 14-16.  /4/ Agent Kempshall
asked respondent for his ticket and some identification;  respondent
replied that he had neither.  Respondent told the agents that his name
was "Sokolow" but that he was traveling under his mother's maiden
name, "Kray." He also claimed that a man named "Marty," whom he had
met on the beach, had purchased the tickets for him.  App. 3a, 57a;
10/29/84 Tr. 14-16;  9/22/86 Tr. 38-40, 44;  McCarthy Aff. 1.

   Agent Kempshall then told respondent that his luggage would be
examined by a narcotics detection dog, and respondent carried his bags
to the airport customs area.  At 6:54 -- less than 15 minutes after
the agents had approached respondent -- the dog alerted to
respondent's brown shoulder bag.  /5/ The agents then arrested
respondent, moved him to the DEA airport office, and sought a warrant
authorizing a search of the shoulder bag.  In the meantime, a woman
with an extensive record of narcotics and prostitution arrests was
brought into the office on an unrelated matter.  She identified
respondent as a person she knew as "Andrew" who had purchased two or
three "papers" of heroin a day over the past two years from her
supplier.  App. 4a, 57a-58a;  10/29/84 Tr. 16-21;  9/22/86 Tr. 51-59,
76;  McCarthy Aff. 1.

   After the warrant issued, the agents searched the brown shoulder
bag but found no narcotics.  /6/ The agents found some incriminating
documents, however, /7/ and they had the narcotics detection dog
re-examine the remaining three bags.  That time, the dog alerted to a
medium-sized carry-on bag.  Because it was then 9:30 p.m., the agents
told respondent that they could not obtain a search warrant for the
bag until the following morning.  They permitted respondent to leave
but kept his luggage.  At 7:45 a.m. the next day, a second narcotics
detection dog also examined the carry-on bag, and that dog also
detected narcotics.  The agents obtained a warrant to search the bag
and found 1,000 grams of cocaine inside it.  App. 4a, 58a-59a;
9/22/86 Tr. 62-64, 88-89.

   2. Respondent moved to suppress the cocaine.  Following an
evidentiary hearing, a magistrate recommended that the motion be
denied.  The magistrate found that the agents had a reasonable
suspicion that respondent was involved in drug trafficking when they
approached him at the curb outside the airport (App. 56a-62a).  The
magistrate also found that, once the narcotics detection dog
discovered narcotics in respondent's luggage, the arrest of respondent
and the ensuing seizure and searches of his luggage were supported by
probable cause (id. at 60a-61a).  The district court agreed with the
magistrate and denied respondent's suppression motion (id. at
52a-55a).

   3. The court of appeals reversed by a divided vote (App. 34a-46a).
/8/ The court held that respondent was seized at the curb outside the
airport and that the seizure was not supported by a reasonable
suspicion (id. at 39a-44a).  In concluding that the seizure was
unlawful, the court separately examined each fact known to the agents
who stopped respondent and concluded that none of them amounted to a
reasonable suspicion that respondent was involved in narcotics
trafficking.

   The court found that only one fact gave any support to the agents'
suspicion -- respondent's purchase of the tickets with a large wad of
cash.  The court acknowledged that that fact, standing alone, was
"close" to "particularized evidence of suspicious activity" (App.
42a).  Nonetheless, the court concluded that respondent's $2100 cash
purchase of airline tickets was not sufficient, standing alone, to
justify stopping respondent, because it did not indicate that he was
engaged in criminal activity at that moment (id. at 43a).  The court
therefore held that respondent's detention was illegal and ordered the
evidence suppressed.

   Judge Wiggins dissented (App. 44a-46a).  He found that respondent's
$21000 cash purchase of airline tickets "is sufficiently suspicious
that the addition of (a) few other relatively anomalous
characteristics could support a founded suspicion of illegal activity"
(id. at 45a).  He disagreed with the majority's contention that the
cash payment was not evidence of "'ongoing' criminal activity," since
large amounts of cash are often used "to conceal illicit travel
patterns, or to buy drugs" (ibid).  When respondent's cash purchase
was added to the brevity of the trip, Miami's reputation as a known
source city for drugs, and the lack of checked luggage, Judge Wiggins
concluded that the agents had a reasonable suspicion that respondent
was engaged in criminal activity (id. at 45a-46a).  Judge Wiggins
criticized the majority for looking at "each evidentiary factor
discretely." As he put it, the majority should have viewed "the whole
mosiac rather than each tile" (id. at 46a).

   4.  On rehearing the government argued that, under United States v.
Cortez, 449 U.S. 411 (1981), the majority had erred by examining each
fact known to the agents in isolation rather than by examining "the
totality of the circumstances -- the whole picture" (id. at 417).

   The court of appeals filed a new opinion taking a different
approach, but again set aside respondent's conviction on the ground
that the stop was not supported by a reasonable suspicion that
respondent was engaged in criminal conduct (App. 1a-21a).  The court
concluded that the facts in this case described "not ongoing criminal
activity but a class of people that is predominantly criminal" (id. at
10a).  It concluded that the government had "unwittingly equate(d)
evidence of behavior that a criminal may engage in with behavior
indicating an ongoing crime" (id. at 8a (emphasis in original)).

   The court of appeals segregated the facts that bear on the
reasonable suspicion inquiry into two categories:  facts describing
ongoing criminal activity, and facts describing personal
characteristics shared by drug couriers.  In the first category, the
court placed factors such as a person's use of an alias or his evasive
movement through an airport;  at least one such factor, the court
held, must be present to justify a finding of reasonable suspicion
(App. 11a-12a).  In the second category, the court placed factors such
as cash payment for tickets, a quick trip to and from a major source
city, nervousness, manner of attire, and the absence of checked
luggage.  Those factors, the court held, are merely characteristics
shared by drug couriers in general and are not evidence of ongoing
criminal conduct (id. at 12a).  Those factors are relevant, the court
held, only if at least one factor from the first category is present
(id at 14a, 19a).  Even then, the court further held, agents may rely
on factors in the second category only if they can demonstrate with
"(e)mpirical documentation" (id. at 13a) or "statistical evidence"
(id. at 14a) that the factor in question does not describe the
behavior of "significant numbers of innocent persons" (id. at 13a;
see also id. at 12a).

   The court then applied its two-part test to the facts in this case
(App. 18a-20a).  It found no evidence that respondent had used an
alias, despite the discrepancy between the name he gave the airline
ticket agent when purchasing the tickets and the name under which his
telephone number was listed, since "it is not unusual for persons with
different last names to share a common residence and telephone" (id.
at 18a).  The court also discounted respondent's nervousness while
waiting for a connecting flight at the Los Angeles airport, because
"(t)here is no evidence on the record to indicate that (respondent's)
nervousness was indicative of an attempt to evade detection" (id. at
19a-20a).  In the court's view, "(n)ervousness would appear to be a
normal human reaction to air travel today, with the seemingly growing
risk of mid-air collision and the near certainty of delays that may
interrupt the plans of travelers" (id. at 20a).  Having discounted the
evidence that respondent was traveling under an alias and that he
seemed to be nervous, the court rejected as "unsubstantiated" the
government's contention that the combination of all the facts in this
case "will rarely, if ever, describe an innocent traveler" (ibid.).

   Judge Wiggins again dissented (App. 21a-33a).  He noted that the
detention of respondent "was brief, served the important law
enforcement purpose of detecting drug couriers, and lasted no more
than necessary to effectuate this purpose" (id. at 22a).  He stated
that in his view the majority's approach was "overly mechanistic" and
"contrary to the case-by-case determination of reasonable articulable
suspicion based on all the facts" (id. at 25a;  emphasis in original).
 Judge Wiggins explained that, "(i)n evaluating the whole picture, a
trained officer may draw inferences and make deductions that would
escape an untrained observer.  Conduct seemingly innocent may, viewed
as a whole, appear suspect to one familiar with the practices of drug
smugglers and the methods used to avoid detection" (id. at 24a).  The
majority's approach, Judge Wiggins warned, "effectively throttles the
efforts of drug enforcement agents to combat escalating narcotics
trafficking" (id. at 33a) and would render invalid "many, and perhaps
all, Terry stops that rely upon drug courier profile characteristics"
(id. at 21a).

   In Judge Wiggins' view, the facts known to the agents were
sufficient to establish a reasonable suspicion (App. 28a-29a).  He
placed particular emphasis on respondent's $2100 cash purchase of
airline tickets, because "(i)nnocent persons do not characteristically
carry thousands of dollars in twenty dollar bills on their persons"
(id. at 28a).  Such a large cash payment is inconsistent with a
legitimate business trip, he found, since it does not provide a paper
trail for reimbursement or tax deductions (ibid.).  Judge Wiggins also
noted that the brevity of the trip and the lack of checked luggage
were inconsistent with a pleasure trip (id. at 28a-29a).  Finally,
Judge Wiggins remarked that respondent's nervous and watchful behavior
during the stopover on his return trip is "hardly a sign of an
innocent traveler" (id. at 29a).

                   REASONS FOR GRANTING THE PETITION

   The court of appeals has erroneously decided a question of great
importance to the national effort to halt the transportation of
narcotics within this country and from abroad.  Since 1974, the Drug
Enforcement Administration has operated a drug courier surveillance
program at numerous airports throughout the nation in order to
identify and intercept drug traffickers.  That program is an important
part of the DEA's drug enforcement efforts, because it provides the
DEA with the opportunity to intercept narcotics at a point in the
distribution chain above the level that can be reached by more
traditional undercover operations.  Many of the factors present in
this case, but discarded by the court of appeals, are ones on which
narcotics agents routinely rely when intercepting drug couriers.
Accordingly, if the two-part formula adopted by the court of appeals
is allowed to stand, the decision in this case will outlaw a large
percentage of the "reasonable suspicion" stops of suspected drug
traffickers passing through airports within the Ninth Circuit.  /9/

   1. When the agents stopped respondent as he was leaving the
Honolulu airport on July 25, 1984, they knew the following:  (1)
respondent had left Honolulu three days earlier on a flight to Miami;
(2) at the time, he was dressed in a black jumpsuit and was wearing a
large amount of gold jewelry;  (3) he paid $2100 for two round-trip
tickets between Honolulu and Miami;  (4) the tickets were for a flight
leaving that day, and they carried an open return;  (5) respondent
paid for the tickets in cash, from a roll of $20 bills that appeared
to contain about $4000;  (6) he was traveling under a name that did
not match the name in which his telephone was listed, even though his
voice was on the answering machine that responded at that number;  (7)
he was nervous when he was buying the tickets;  (8) neither he nor his
companion checked any luggage although they were carrying four bags
with them;  (9) respondent's destination, Miami, is the main source
city for cocaine in the United States;  (10) respondent stayed in
Miami only about 48 hours, even though the travel time between
Honolulu and Miami is 10 hours each way;  (11) he returned to Miami by
an indirect route that included two stopovers;  (12) he appeared
nervous and watchful while awaiting his connecting flight in the Los
Angeles airport;  (13) he and his companion also checked no luggage on
their return flight from Miami;  and (14) respondent was still wearing
the black jumpsuit and gold jewelry when he arrived in Honolulu.

   The court of appeals found that evidence insufficient to constitute
reasonable suspicion and to justify a brief investigative stop of
respondent, even though the evidence was stronger than the evidence in
all four of this Court's previous airport stop cases.  See Florida v.
Rodriguez, 469 U.S. 1 (1984);  Florida v. Royer, 460 U.S. 491 (1983);
Reid v. Georgia, 448 U.S. 438 (1980);  United States v. Mendenhall,
446 U.S. 554 (1980).  In Florida v. Royer, for example, eight Members
of the Court agreed that the evidence available to the officers was
sufficient to establish reasonable suspicion, even though the agents
had less evidence than the agents had in this case.  See 460 U.S. at
502 (opinion of White, J.);  id. at 515-516 (Blackmun, J.,
dissenting);  id. at 523-524 (Rehnquist, J., dissenting).  In Royer,
the officers learned that Royer was traveling under an alias, that he
had paid cash for his ticket, that he had put only a name and not an
address on his checked luggage, that he was young and casually
dressed, and that he seemed nervous while walking through the Miami
airport.  In this case, as in Royer, the agents had a strong
indication that respondent was traveling under an alias, and they knew
that he had made a huge cash payment for his ticket, that he was
traveling to Miami, that he was young and casually dressed, and that
he was nervous in both the Honolulu and Los Angeles airports.  In
addition, respondent had not checked any bags at all;  his itinerary
was bizarre, to say the least;  and his pattern of travel suggested
neither a business trip nor a vacation.

   The factors relied upon by the agents in this case -- and
discounted by the court of appeals -- are factors commonly relied on
by other courts of appeals in upholding reasonable suspicion stops.
See 3 W. LaFave, Search and Seizure Section 9.3(c), at 446-447 (2d ed.
1987).  Purchasing $2100 worth of airline tickets with a roll 0f $20
bills is highly unusual.  It suggests that an individual wants to
avoid leaving a trail of receipts behind him, which in turn suggests
that he is not on a legitimate business trip.  /10/ The agents had
reason to believe that respondent was using an alias, which is common
among drug couriers.  /11/ Respondent's destination -- Miami -- was
clearly an important factor because, as Agent Kempshall testified
(9/22/86 Tr. 66), Miami is the "granddaddy" source city for cocaine.
/12/ The brevity of respondent's trip to Miami is also consistent with
drug trafficking.  Respondent spent 20 hours in transit and only 48
hours at his destination, which makes it unlikely that he went to
Miami for a vacation.  /13/ Respondent checked no luggage, even though
he and his companion had four bags with them, which is consistent with
the modus operandi of a drug courier, since it allows him to exit the
airport terminal quickly.  /14/ Finally, respondent was nervous when
he purchased his tickets, and he nervously scanned the waiting area at
the Los Angeles airport while he was en route to Hawaii.  Nervousness
may be a characteristic shared by many criminals, but it is
particularly relevant in the investigation of drug couriers because of
their heightened concern about apprehension while they are passing
through airports in possession of large amounts of narcotics or cash.
/15/

   2. In addition to being contrary to prior airport stop cases from
this Court and other courts of appeals, the analysis by the court of
appeals in this case is contrary to several of the general principles
that this Court has set forth in analyzing the Fourth Amendment
principles that apply to investigative stops.  Since Terry v. Ohio,
392 U.S. 1 (1968), it has been clear that a law enforcement officer
may briefly stop and detain a person for investigative purposes when
the officer can point to specific facts that reasonably indicate that
the person detained may be involved in criminal activity, even though
the facts known to the officer do not constitute probable cause to
believe that the suspect has committed a crime.

   Terry and its successors have established three important
principles for "reasonable suspicion" cases.  First, in order to
justify stopping a suspect for questioning, a law enforcement officer
is not required to eliminate all innocent explanations for the
suspect's behavior, or even to determine that the suspect's actions
are more likely to be culpable than innocent.  Rather, the officer may
act when he "observes unusual conduct which leads him reasonably to
conclude in light of his experience that criminal activity may be
afoot" (Terry, 392 U.S. at 30).  That standard demands only "some
minimum level of objective justification to validate the detention or
seizure." INS v. Delgado, 466 U.S. 210, 217 (1984).  /16/ Second, in
determining whether a set of factors gives rise to reasonable
suspicion, it is wrong to consider each factor in isolation and to
judge whether, standing alone, it supports a reasonable suspicion.
"(T)he essence of all that has been written is that the totality of
the circumstances -- the whole picture -- must be taken into account"
when determining if there is a reasonable suspicion that a person is
connected with criminal activity.  United States v. Cortez, 449 U.S.
441, 417 (1981).  See also Terry, 392 U.S. at 22 ("a series of acts,
each of them perhaps innocent in itself * * * taken together (may)
warrant() further investigation").  Third, the evidence known to an
officer must be viewed, "fact on fact and clue on clue," in light of
the inferences and deductions that a trained and experienced officer
would reach, "inferences and deductions that might well elude an
untrained person." Cortez, 449 U.S. at 418, 419.  /17/

   Rather than simply applying those principles, the court of appeals
devised a novel two-part test to be used in assessing reasonable
suspicion stops in the airport setting.  The effect of that test,
however, was to obscure the probative force of the evidence in this
case -- evidence which, when viewed in a commonsense fashion, amply
justified the agents' suspicions that respondent's curious three-day
journey between Honolulu and Miami had a criminal purpose.  /18/

   The court of appeals first divided the factors bearing on
reasonable suspicion into two categories:  those that indicate ongoing
criminal activity, and those that merely reflect conduct that
criminals engage in.  The court then held that factors from the second
category could not justify a finding of reasonable suspicion absent
some factor from the first category, and that in order to rely on
factors from the second category, the government would have to
introduce empirical or statistical evidence establishing that those
factors serve to identify criminals, rather than a large number of
innocent persons.

   The court of appeals' test treats the factors bearing on reasonable
suspicion precisely the way Terry said they should not be treated.  It
creates a false dichotomy between direct evidence, which the court of
appeals termed evidence indicative of criminal activity, and
circumstantial evidence, which the court of appeals termed evidence
indicative of criminal character.  Factors that indicate that a person
is a drug smuggler do so precisely because they tend, to a greater or
lesser degree, to be associated with the act of drug smuggling.  Thus,
the factors bearing on the issue of reasonable suspicion cannot be
neatly lumped into one of two categories, as the court of appeals has
done in this case.

   To divide the factors typically relied on by police into the two
categories invented by the court of appeals has the effect of
improperly denigrating certain factors.  For example, it assigns too
little weight to a suspect's nervousness, which the court of appeals
placed in the category describing criminal character rather than
describing ongoing criminal activity.  While nervousness in an airport
may be exhibited by both drug couriers and innocent persons, it is
logically consistent with ongoing criminal activity and is an
important factor in an agent's assessment whether an individual is
likely to be carrying drugs at a particular time.  See, e.g.,
Mendenhall, 446 U.S. at 564 (opinion of Powell, J.);  3 W. LaFave,
supra, Section 9.3(c), at 447.  Nervousness is a natural reaction of a
courier who is transporting drugs or cash and is looking around the
airport for agents who may be conducting surveillance.  For a courier,
carrying narcotics through an airport is apt to provoke
extraordinarily high anxiety, which is likely to manifest itself in
demonstrable, albeit subtle, ways.  /19/

   The court's relegation of the nervousness factor to the second
category also disregards the differences among types of nervousness.
A person may be ill-at-ease or anxious in an airport without giving
rise to suspicion that he is engaged in unlawful activity.  On the
other hand, when a person is nervous and watchful, as was petitioner
during his layover in Los Angeles, his nervousness takes on more
significance.  It defies common sense to suppose that officers who
have spent months or years observing thousands of travelers passing
through airports cannot distinguish between the type of nervousness
shown by persons who fear apprehension for criminal activity and the
type of nervousness shown by persons who fear air travel.  Thus, it is
both unrealistic and unresponsive to subtle differences in human
behavior simply to lump nervousness as a whole into the category of
conduct that does not suggest ongoing criminal activity.

   Similarly, the cash purchase of tickets is not simply a
characteristic typical of many criminals, as the court of appeals
seemed to believe.  Instead, it has a logical bearing on the
likelihood that the individual is engaged in criminal conduct at the
time.  Unlike the use of a credit card or a check, the cash purchase
of a ticket enables the individual to travel under an alias without
disclosing his true identity, and it leaves no paper trail that can
tie the traveler to a particular trip.  /20/

   Not checking luggage is also a technique that is often used to
minimize the risk of apprehension in airports, because it enables the
couriers to exit the terminal quickly, thereby miminizing the
opportunity for airport narcotics agents to observe them.  Again, that
factor is more likely to be present when the suspect is engaged in
criminal activity, and less likely when he is merely taking an
innocent trip.

   By relegating to second-class status factors such as nervousness,
the cash purchase of tickets, and the failure to check baggage, and by
requiring empirical proof of the significance of those factors, the
court of appeals violated all three to the principles from Terry that
are set forth above.  Requiring empirical proof that particular
factors are not associated with large numbers of innocent travelers
ignores the principle from Terry that reasonable suspicion does not
require the same level of confidence that is required for proof at
trial or for a showing of probable cause, but only an articulable
basis for believing that criminal activity "may be affoot." It also
ignores the principle that the evidence must be considered as a whole
and the principle that it must be viewed in the light of inferences
that can be drawn by trained law enforcement officers.

   Any number of factors, standing, alone, may describe large numbers
of innocent travelers as well as a large percentage of drug couriers.
For example, wearing casual dress, being young, and not checking
baggage certainly describes many travelers, and for that reason one or
all of those factors would not be enough, standing alone, to justify
an investigative stop.  But those factors, in a particular context and
in conjunction with other factors, can properly lead trained officers
observing the suspect to conclude that there is enough evidence to
distinguish that person from the ordinary traveling public to justify
a brief detention and inquiry.

   Common sense, not statistics, has always been the cornerstone of
the Fourth Amendment.  The Court has made clear that whether the facts
known to a narcotics officer constitute a reasonable suspicion must be
determined by the officer's "common-sense conclusion about human
behavior." Cortez, 449 U.S. at 418 (emphasis added).  The evidence
"must be seen and weighed not in terms of library analysis by
scholars, but as understood by those versed in the field of law
enforcement." Ibid.  See also United States v. Montoya De Hernandez,
473 U.S. 531, 542 (1985);  Mendenhall, 446 U.S. at 563 (opinion of
Powell, J.);  Brown v. Texas, 443 U.S. 47, 52 n.2 (1979);  United
States v. Brignoni-Ponce, 422 U.S. 873, 885 (1975);  Terry, 392 U.S.
at 27.  /21/ By demanding that experienced narcotics agents justify
their commonsense inferences with statistical proof, the court of
appeals essentially reformulated the reasonable suspicion inquiry as
one that must be examined from the viewpoint of an untrained layman, a
perspective flatly inconsistent with the one required by this Court's
decisions.

   The evidence on which narcotics agents rely cannot be disregarded
on the ground that it might not arouse suspicion in a layman.  This
Court has recognized that a trained police officer is a professional
observer of criminal activity and may be "able to perceive and
articulate meaning in given conduct which would be wholly innocent to
the untrained observer." Brown v. Texas, 443 U.S. at 52 n.2.  That
conclusion is hardly surprising.  It should be expected that
experienced narcotics agents will be able to discern criminal conduct
they have been trained to spot.  Indeed, it would make little sense to
train agents in drug enforcement if they can stop and question a
suspect only on grounds that would be equally obvious to any layman.
/22/

   Nor can the evidence known to the officers be disregarded on the
ground that it was subtle.  Narcotics smuggling is a crime of stealth.
 Unlike the crime in Terry, which involved the casing of a store for a
robbery, respondent's crime required no action other than concealment
and escape for its completion.  Respondent's goal was to do as little
as possible in order to avoid detection.  For that reason, it is
hardly surprising that respondent did not engage in conduct that would
have been highly suspicious to a lay observer.  Only by noticing and
piecing together subtle clues can a narcotics agent discern whether a
person is transporting drugs, as respondent turned out to be.

   3.  In sum, the court of appeals' decision in this case is contrary
to this Court's decision in Royer;  it is contrary to the approach
employed by other courts of appeals in analyzing airport stop cases;
and it is contrary to the principles that this Court has established
to guide the application of the Fourth Amendment in the context of
"reasonable suspicion" stops.  This Court should grant review to
resolve those conflicts and to avoid the damage that the decision in
this case, if uncorrected, would do to the government's airport
narcotics detection program in the Ninth Circuit.

                              CONCLUSION

   The petition for a writ of certiorari should be granted.

   Respectfully submitted.

   CHARLES FRIED

      Solicitor General

   WILLIAM F. WELD

      Assistant Attorney General

   WILLIAM C. BRYSON

      Deputy Solicitor General

   PAUL J. LARKIN, JR.

      Assistant to the Solicitor General

   PATTY MERKAMP STEMLER

      Attorney

   FEBRUARY 1988

   /1/ Along with a petition for rehearing, we submitted a suggestion
for rehearing en banc.  As of the date of the filing of this petition,
the court of appeals has not acted on our en banc suggestion.  The
time within which to file a petition, however, runs from the date of
the denial of a rehearing petition, not from the date of the denial of
a suggestion for rehearing en banc.  Sup. Ct. R. 20.4.  Because the
court of appeals denied our rehearing petition on November 4, 1987, in
a new opinion that substantially changed the rationale for the court's
decision, we filed a supplemental petition for rehearing with a
suggestion for rehearing en banc, which is still pending before the
Ninth Circuit.  We will advise the Court of any further action by the
court of appeals that may affect the disposition of this petition.

   /2/ The facts were developed at suppression hearings conducted by
the magistrate and the district court on three separate days.  In
addition, the parties stipulated to the facts contained in the
affidavits of Honolulu Police Officer John McCarthy, which were filed
in support of the several search warrant applications in this case.
11/21/84 Tr. 2-3.

   /3/ After respondent's arrest, the agents learned that "Karl
Herman" was respondent's roommate.  App 2a-3a;  10/29/84 Tr. 3, 10;
9/22/86 Tr. 23-25.

   /4/ Although the agents denied that they had any physical contact
with respondent at that time, the district court, observing that the
government has the burden of proof on the issue, found respondent's
account of the event, in which he claimed that one of the agents
grabbed his arm and guided him back to the sidewalk "reasonably
believable" (App. 47a;  see 10/29/84 Tr. 14-16).

   /5/ The dog had correctly identified the presence of controlled
substances on hundreds of prior occasions (McCarthy Aff. 1).

   /6/ Cocaine residue was later found in that bag (9/22/86 Tr. 62,
64).

   /7/ The agents found airline tickets in the names of Andrew Kray
and James Wodehouse for two round trips from Honolulu to Miami, as
well as Miami hotel receipts for those trips.  The agents also found
handwritten notes that appeared to be records of drug transactions.
In respondent's personal address book, the agents found the names and
addresses of several individuals who were suspected of drug
trafficking.  Finally, the agents found the keys to four safety
deposit boxes.  McCarthy Affs. 2, 3.

   /8/ Before issuing its decision, the court of appeals remanded the
case to the district court and directed the court to make supplemental
findings on several specified questions (App. 50a-51a).  Following a
further evidentiary hearing on remand, the district court reaffirmed
the denial of respondent's suppression motion (id. at 47a-49a).  The
district court found that respondent had been detained at the curb
(id. at 47a), but that the detention was supported by a reasonable
suspicion that respondent possessed narcotics (id. at 47a-48a).

   /9/ Six of the DEA's 28 airport drug courier surveillance programs
are located in cities within the jurisdiction of the Ninth Circuit.

   /10/ The cash purchase of airline tickets is commonly cited to
support a finding of reasonable suspicion.  See, e.g., United States
v. Espinosa -- Guerra, 805 F.2d 1502, 1508 (11th Cir. 1986);  United
States v. Hanson, 801 F.2d 757, 761-763 (5th Cir. 1986);  United
States v. Williams, 726 F.2d 661, 663 (10th Cir.), cert. denied, 467
U.S. 1245 (1984);  United States v. Jodoin, 672 F.2d 232, 234 (1st
Cir. 1982).

   /11/ See, e.g., United States v. Espinosa-Guerra, supra;  United
States v. Hanson, supra;  United States v. Palen, 793 F.2d 853, 857
(7th Cir. 1986);  United States v. Puglisi, 723 F.2d 779, 789 (11th
Cir. 1984);  United States v. Ehlebracht, 693 F.2d 333, 336 (5th Cir.
Unit B 1982);  United States v. Jodoin, 672 F.2d at 233.

   /12/ See, e.g., United States v. Haye, 825 F.2d 32, 34 (4th Cir.
1987) (Miami is a "known source() of drug supplies");  United States
v. Espinosa-Guerra, 805 F.2d at 1508;  United States v. Publisi, 723
F.2d at 789.

   /13/ See United States v. Hanson, supra;  United States v. Palen,
793 F.2d at 857 (five-day stay in Florida is "a relatively short
period of time * * * for a tourist from Alaska");  United States v.
Ehlebracht, 693 F.2d 336.

   /14/ See United States v. Espinosa-Guerra, supra.

   /15/ Numerous courts have treated nervousness as an important
factor in determining the existence of reasonable suspicion.  See,
e.g., United States v. Borys, 766 F.2d 304, 311-312 (7th Cir. 1985),
cert. denied, 474 U.S. 1082 (1986);  United States v. Williams, 754
F.2d 672, 674 (6th Cir. 1985);  United States v. Tolbert, 692 F.2d
1041, 1047 (6th Cir. 1982), cert. denied, 464 U.S. 933 (1983);  United
States v. Ramirez-Cifuentes, 682 F.2d 337, 342 (2d Cir. 1982).

   /16/ See United States v. Montoya De Hernandez, 473 U.S. 531, 541
(1985);  Adams v. Williams, 407 U.S. 143, 145-146 (1972);  cf. United
States v. Ramsey, 431 U.S. 606, 612-613 (1977) ("reasonable cause"
standard of 19 U.S.C. 482 authorizing customs officers to search
imported merchandise is less than probable cause);  see generally 3 W.
LaFave, supra, Section 9.3(b), at 431 ("it would seem clear (from
Terry) that a more-probable-than-not standard is never applicable to a
brief stopping for investigation");  id. at 432 & n.58 (collecting
cases in which courts "quite properly" upheld a Terry stop even though
the actions observed were consistent with innocent activity).

   /17/ See also United States v. Mendenhall, 446 U.S. 554, 563-564
(1980) (opinion of Powell, J.);  Brown v. Texas, 443 U.S. 47, 52 n.2
(1979) (a trained, experienced officer "is able to perceive and
articulate meaning in given conduct which would be wholly innocent to
the untrained observer");  Unites States v. Brignoni-Ponce, 422 U.S.
873, 885 (1975) ("In all situations the officer is entitled to assess
the facts in light of his experience in detecting illegal entry and
smuggling.");  Terry, 392 U.S. at 27 ("due weight must be given * * *
to the specific reasonable inferences which (the officer) is entitled
to draw from the facts in light of his experience").

   /18/ The two-part test devised by the court of appeals recalls the
two-part test that this Court formerly applied in making probable
cause determinations.  See Spinelli v. United States, 393 U.S. 410
(1969);  Aguilar v. Texas, 378 U.S. 108 (1964).  In Illinois v. Gates,
462 U.S. 213 (1983), the Court rejected that two-part test in favor of
a "totality of the circumstances" approach to probable cause.  The
Court did so because the Aguilar-Spinelli test did not permit "a
balanced assessment of the relative weights of all the various indicia
of reliability (and unreliability)" and "encouraged an excessively
technical dissection of informants' tips, with undue attention being
focused on isolated issues that simply connot sensibly be divorced
from the other facts presented to the magistrate." Id. at 234-235
(footnote omitted).  The two-part test adopted by the court of appeals
is subject to precisely the same criticism:  it impedes, rather than
assists, clarity of analysis of the strength of the evidence adduced
in support of the agents' actions.

   /19/ Curiously, the court of appeals in its first opinion -- before
it had focused on the fact that there was evidence of nervousness in
this case -- put the nervousness factor in the first category, not the
second.  See App. 43a (emphasis in original) ("Sokolow's payment in
cash is quite unlike a suspect's looking around to see if he was being
watched, appearing nervous, taking evasive action, or using an alias
while traveling, all of which at least tend to raise a suspicion that
criminal activity is going on at that time.").

   /20/ Again, the contrast between the court of appeals' first
opinion and its second is striking.  In the first opinion, the court
regarded the cash purchase of tickets as being "close," standing
alone, to establishing reasonable suspicion (App. 42a).  In the second
opinion, however, the cash purchase of tickets had tumbled into the
second category of factors and was not considered relevant at all.

   /21/ Even in connection with probable cause, the Court has made
clear that that no "numerically precise degree of certainty" is
necessary (Illinois v. Gates, 462 U.S. 231, 235 (1983)) and that the
question whether probable cause exists must be answered on the basis
of the "nontechnical, common-sense judgments of laymen applying a
standard less demanding than those used in more formal legal
proceedings" (id. at 235-236).

   /22/ The narcotics agents involved in this case had extensive
experience in apprehending drug couriers.  Officer McCarthy had been a
police officer for ten years, he had worked with the Drug Enforcement
Administration at the Honolulu airport for two years, and he had
participated in more than 300 narcotics investigations, two-thirds of
which involved cocaine and most of which occurred at the airport.  DEA
Kempshall had 15 years' experience and had participated in several
thousand narcotics investigations, about half of which involved
cocaine.  He had been patrolling the Honolulu airport for narcotics
traffickers since 1979, and was conversant with the methods used to
transport narcotics as a result of discussions with fellow agents and
with drug couriers.  9/22/86 Tr. 4-6, 26-30, 66-69.

   APPENDIX