UNITED STATES OF AMERICA, PETITIONER V. BRADLEY THOMAS JACOBSEN AND
DONNA MARIE JACOBSEN

   No. 82-1167

   In the Supreme Court of the United States

   October Term, 1982

   On writ of certiorari to the United States Court of Appeals for the
Eighth Circuit

   Brief for the United States

            TABLE OF CONTENTS
   Opinion below
   Jurisdiction
   Statement
   Summary of argument
   Argument
      The agents were not required to obtain a warrant before
      conducting a chemical test of the powder lawfully in their
      possession to determine whether it was cocaine
      A. Law enforcement officers need not obtain a warrant
          before conducting any chemical analysis, and a chemical
          analysis that reveals only whether a substance is
          contraband is not a search within the meaning of the
          Fourth Amendment
      B. The actions taken by the agents preparatory to
          the chemical analysis did not violate the Fourth
          Amendment
   Conclusion

                             OPINION BELOW

   The opinion of the court of appeals (Pet. App. 1a-9a) is reported
at 683 F.2d 296.

                             JURISDICTION

   The judgment of the court of appeals (Pet. App. 11a) was entered on
July 27, 1982.  A petition for rehearing was denied on October 14,
1982 (Pet. App. 10a).  On December 2, 1982, Justice Blackmun extended
the time in which to file a petition for a writ of certiorari to and
including January 12, 1983.  The petition was filed on that date and
granted on March 7, 1983 (J.A. 76).  The jurisdiction of this Court
rests on 28 U.S.C. 1254(1).

                          QUESTION PRESENTED

   Whether law enforcement officers must obtain a search warrant
before conducting a chemical field test to determine whether a
substance that has lawfully come into their possession and that
appears to be cocaine is in fact cocaine.

                               STATEMENT

   After a jury trial in the United States District Court for the
District of Minnesota, respondents were each convicted of possessing
cocaine with intent to distribute it, in violation of 21 U.S.
841(a)(1), and conspiring to commit that offense, in violation of 21
U.S.C. 846.  Respondent Bradley Jacobsen was also convicted of
assaulting a federal officer, in violation of 18 U.S.C. 111 (Pet. App.
3a).  /1/ The court of appeals reversed all the narcotics convictions
on the ground that they were based on evidence obtained in violation
of the Fourth Amendment (id. at 8a).  /2/

   1. On May 1, 1981, an employee of Federal Express, a private
freight carrier, discovered that a cardboard box given to Federal
Express for shipment had inadvertently been damaged in transit (Pet.
App. 1a).  Pursuant to a written company policy adopted "because of
the possibility of insurance claims" (id. at 17a), a Federal Express
supervisor ordered that the package be completely opened.  Inside the
package was a ten-inch-long tube wrapped with gray tape;  inside the
tube were four transparent plastic bags, one inside the other.
Federal Express employees cut open the tube, removed the bags, and saw
that the innermost bag contained a white powder.  Id. at 1a, 17a;
J.A. 25, 41.

   The Federal Express employees believed that the white powder might
be an illicit substance, and they notified the Drug Enforcement
Administration.  They also replaced the bags in the tube and placed
the tube in the open box.  DEA agents went to the Federal Express
office, removed the bags from the tube, and conducted a chemical field
test on a small sample of powder from the plastic bags.  The test
indicated that the powder was cocaine.  Pet. App. 1a-2a, 18a;  J.A.
60.  The package was later found to contain approximately six and
one-half ounces of cocaine, with a street value of over $72,000 (J.A.
69;  Tr. 120, 441).  /3/

   The DEA agents then rewrapped the package after extracting another
sample for further laboratory testing.  The package had been addressed
to "Mr. D. Jacobs" at an address that the agents ascertained to be
respondents' residence.  DEA computer files mentioned respondent
Bradley Jacobsen in connection with two previous reports of cocaine
distribution.  On the basis of that information and what they had
learned at the Federal Express office, the agents sought and obtained
a warrant to search the house to which the package was addressed.
Pet. App. 2a, 18a-19a.

   That afternoon, DEA Agent Lewis, in ordinary clothes, went to
respondents' house and delivered the rewrapped package.  Respondent
Donna Jacobsen signed for the package and accepted it.  Approximately
one hour later, Agent Lewis returned to the house with the search
warrant and several other officers.  Respondent Bradley Jacobsen
opened the door, and Agent Lewis identified himself as a law
enforcement officer.  Bradley Jacobsen then slammed the door into
Agent Lewis's face, breaking his glasses and knocking him down, and
yelled:  "Its the police -- flush it." Pet. App. 2a, 19a;  Tr. 43.

   The officers forced the door open and entered the house.  They
found traces of cocaine, cocaine paraphernalia, and burned remnants of
the package.  Pet. App. 2a.

   2. Before trial, respondents unsuccessfully moved to suppress the
evidence found in their house.  The district court noted that
respondents "concede that the initial search of the package and
discovery of the cocaine by the Federal Express employees was not
proscribed by the fourth amendment because it was done by private
persons" (Pet. App. 13a).  The district court also ruled that "when a
private person makes an initial search of a closed container and then
turns the container over to government authorities, the reopening of
the container does not constitute a separate search requiring a
warrant" (id. 14a-15a).

   The court found that before the DEA agents arrived at the Federal
Express office, "the Federal Express employees had already opened the
box and removed the bags containing the white powder from the gray
tube" (Pet. App. 15a).  Consequently, "(t)he only investigation of the
contents of the box beyond the investigation by Federal Express
employees was the field test by the DEA agents" (ibid.).  The district
court then rejected as "without foundation" respondents' contention
that "when federal agents lawfully receive possession of a substance
they believe to be contraband, they must obtain a search warrant
before (performing) a field test to verify the chemical content of the
contraband" (ibid.).

   3. The court of appeals held that the district court erred in not
suppressing the evidence found in respondents' house.  The court of
appeals noted that respondents did not contend that the Federal
Express employees' inspection of the package violated the Fourth
Amendment.  The court also stated that government's examination of the
package would not violate the Fourth Amendment so long as it was
"confined to what (was) exposed by the private search." Pet. App. 5a.
But the court of appeals upheld respondents' contention that "the
federal agents' search exceeded the scope of the private search" (id.
at 4a;  see id. at 5a-6a).  The court ruled that "(t)he private search
in this case exposed bags of powder, but (respondents') initial
reasonable expectation of privacy that the package's contents would
remain private was not entirely frustrated by the private search" (id.
at 6a).

   Specifically, the court of appeals held that the agents violated
the Fourth Amendment by conducting the field test of a sample of the
powder.  The court relied exclusively on Walter v. United States, 447
U.S. 649 (1980), in which four Justices of this Court (with a fifth,
Justice Marshall, concurring in the judgment) concluded that federal
agents violated the Fourth Amendment when they failed to obtain a
warrant before viewing, with the aid of a projector, films that
private parties had lawfully acquired and delivered to them but had
not themselves viewed on a projector.  The court of appeals declared
that "(t)he invasion of privacy and collection of inculpatory evidence
involved in testing unidentified substances is parallel to the
investigation and intrusion involved in screening a film" (Pet. App.
7a n.4).  The court explained (id. at 6a):

         The DEA agents' extension of the private search precisely
      parallels that in Walter.  In both cases, viewing the objects
      with unaided vision produced only an inference of criminal
      activity.  In both cases, government agents went beyond the
      scope of the private search by using mechanical or chemical
      means to discover the hidden nature of the objects.  The
      governmental activity represents a significant extension of the
      private searches because it revealed the content of the films in
      Walter and, here, the composition of the powder.

   The court of appeals accordingly concluded that, because none of
the recognized exceptions to the warrant requirement applied, the DEA
agents violated the Fourth Amendment when they conducted the field
test without a warrant.  The court then noted that "(t)he finding of
cocaine in a package being sent to (respondents') home was the core of
the affidavit which justified the issuance of the warrant to search
the * * * home" (Pet. App. 8a), and it asserted that "(w)ithout the
statement that a test indicated the presence of cocaine in the powder,
the affidavit does not provide probable cause to believe (respondents)
possessed cocaine in their home" (ibid.).  The court ordered that the
fruits of the search of respondents' home -- drug paraphernalia,
traces of cocaine, and burned remnants of the package -- be
suppressed.  Ibid.

   Senior District Judge Becker, sitting by designation, concurred
specially "with serious reservations" (Pet. App. 9a).  He indicated
that he believed the decision in Walter required the result reached by
the court of appeals but that he agreed generally with the views
expressed by Justice Blackmun's dissent in Walter.  The government's
petition for rehearing was denied, with three judges voting to rehear
the case en banc (id. at 10a).

                          SUMMARY OF ARGUMENT

   A. The court of appeals plainly erred in concluding that the agents
had to obtain a warrant before conducting the field test.  A chemical
analysis of a substance that is already in the possession of the
authorities will seldom, if ever, reveal any additional information
that a reasonable, innocent person would want to keep private.
Individuals simply do not use the molecular structure of a chemical
substance as a respository for their secrets.

   In any event, any legitimate privacy interest that a person might
in some exceptional circumstances have in the chemical composition of
a substance he owns is not implicated in this case.  The field test
conducted by the DEA agents here was capable of revealing only one
thing -- whether the substance discovered by the Federal Express
employees was cocaine.  Had that substance not been cocaine, the test
would have revealed nothing about it.  The test was therefore
incapable of disclosing any information whatever about an innocent
substance, an innocent activity, or an innocent person;  the only
information it revealed was information that respondents could have no
legitimate interest in keeping private.  For these reasons, the field
test could not possibly have invaded any interest protected by the
Fourth Amendment.  When the government is able to obtain evidence of a
crime without infringing any legitimate, socially protected interest,
it is simply irrational to restrict its authority to do so.

   At the same time, the court of appeals' holding would impose
extraordinary burdens on the investigation of drug offenses.  Law
enforcement officers routinely perform chemical analyses of suspicious
substances, and the logic of the court of appeals' warrant requirement
cannot be limited to analyses performed on substances obtained through
a private search like the one involved here.  Consequently, under the
court of appeals' approach, law enforcement officers would have to
obtain literally thousands of additional warrants each year.
Moreover, although the results of field tests and chemical analyses
have been used in countless prosecutions in the past, we know of no
other court that has ever suggested that the government must have a
warrant before it can perform such a test.  This consensus is further
evidence that the court of appeals' novel holding here was in error.

   B. Respondents also incorrectly suggest, as do certain passages in
the court of appeals' opinion, that the actions taken by the agents
preparatory to the chemical analysis violated the Fourth Amendment.
It is clear that the agents lawfully came into possession of the
package that had been sent to respondents;  that package was initially
searched by private parties -- the Federal Express employees -- who
turned it over to the DEA, and it is well established that the Fourth
Amendment does not apply to private searches.  In removing the
transparent bags from the package, the agents did not exceed the scope
of the private search.  Nor was it a search to open the plastic bags
in order to obtain a sample for testing;  a transparent container is
the best example of a container the "contents (of which) can be
inferred from (its) outward appearance." Arkansas v. Sanders, 442 U.S.
753, 764-765 n.13 (1979).  Finally, the removal and destruction of the
minuscule amount of cocaine needed for testing did not violate the
Fourth Amendment;  in view of the small amounts involved, and the
abundant grounds the agents had to believe that it was contraband,
this was surely not an unreasonable seizure, if it was a seizure at
all.  In any event, probable cause alone, without a warrant,
ordinarily suffices to sustain the reasonableness of a seizure.

                               ARGUMENT

 THE AGENTS WERE NOT REQUIRED TO OBTAIN A WARRANT BEFORE CONDUCTING A
CHEMICAL TEST OF THE POWDER LAWFULLY IN THEIR POSSESSION TO DETERMINE
WHETHER IT WAS COCAINE

   The court of appeals' reversal of respondents' convictions appears
to rest in large measure, if not entirely, on the conclusion that the
chemical field test was a search within the meaning of the Fourth
Amendment because it "revealed * * * the composition of the powder"
(Pet. App. 6a), and that it accordingly could not be undertaken
without a warrant.  We first explain, in subpoint A, why this
unprecedented and mischievous conclusion is plainly wrong.  Then, in
subpoint B, we refute the contention apparently made by respondents
(see Br. in Opp. 6-8), with some support from passages in the court of
appeals' opinion, that actions taken by the agents preparatory to the
field test -- such as removing the plastic bags from the tube and
extracting samples for testing -- also violated the Fourth Amendment.

 A. Law Enforcement Officers Need Not Obtain a Warrant Before
Conducting Any Chemical Analysis, and a Chemical Analysis That Reveals
Only Whether a Substance Is Contraband Is Not a Search Within the
Meaning of the Fourth Amendment.

   1. The Fourth Amendment does not regulate every action that a law
enforcement officer takes in investigating crime;  it applies only to
"searches and seizures." And the government has not conducted a search
unless it has intruded on some person's "legitimate expectation of
privacy." See, e.g., United States v. Knotts, No. 81-1802 (Mar. 2,
1983), slip op. 4-5;  Smith v. Maryland, 442 U.S. 735, 740-741 (1979);
 Terry v. Ohio, 392 U.S. 1, 9 (1968).  It is not enough, of course,
that a person expects, or hopes, that his activities will go unnoticed
by the authorities;  that "expectation (must) be one that society is
prepared to recognize as 'reasonable'" or legitimate.  Katz v. United
States, 398 U.S. 347, 361 (1967) (Harlan, J., concurring);  see, e.g.,
Rakas v. Illinios, 439 U.S. 128, 144 n.12 (1978).

   The concept of a "legitimate" expectation of privacy is not
self-defining.  To a considerable extent, of course, the Court looks
to whether the information in question was acquired by seeing or
hearing that which is exposed to public perception.  A government
agent can learn a great deal of information about an individual by,
for example, tracking his movements on the public roads for an
extended period of time or recording the telephone numbers he dials,
but the Court has concluded that neither of these investigative
measures constitutes a search regulated by the Fourth Amendment.
United States v. Knotts, supra;  Smith v. Maryland, supra.  Even where
there is some intrusion into areas that are not public, such as
privately owned but open fields, the Court considers the extent to
which a typical member of our society would reasonably expect to
maintain a meaningful degree of privacy from uninvited intruders;
where there would in practice be little or no such expectation, an
official intrusion into the area is not considered a search.  Hester
v. United States, 265 U.S. 57 (1924).  The Court similarly draws upon
common understandings about society's weighting of personal privacy
interests in assessing the "standing" of a particular defendant to
complain about a search that does invade the privacy interests of
someone, but not necessarily of the individual before the bar.  See,
e.g., Rawlings v. Kentucky, 448 U.S. 98, 104-105 (1980);  Rakas v.
Illinois, supra, 439 U.S. at 140-149.  The fundamental theme informing
these related inquiries is that the protections afforded by the Fourth
Amendment apply only where there is a significant danger that
government action will intrude into an area which a significant
segment of our society regards as enjoying meaningful privacy
attributes -- that is, where there is a material danger that the
government action will reveal matter both that people generally wish
to guard from public knowledge and that they have taken reasonable
precautions to conceal from public access.

   2. a. Once the authorities have lawfully come into possession of a
substance, a chemical analysis of it will seldom reveal any additional
information that its owner might legitimately wish to keep private.
For that reason, a chemical analysis will rarely, if ever, interfere
with any interest protected by the Fourth Amendment.

   Individuals simply do not "lock" their secrets into the molecular
structure of a substance in the way they might, for example, place
private objects in certain containers, private thoughts on a tape
recording, or private activities on film.  An analysis might enable
the government to learn that a white powdered substance that appeared
to be an illicit drug was actually talcum powder or sugar;  but in
learning that a suspicious substance already visible to government
agents is actually some innocent material, the government has not
invaded any person's privacy in any meaningful way.  Indeed, people
routinely label innocent substances, so that their composition will be
immediately apparent to anyone who is entitled to view them.  When an
innocent substance is not labelled, that is generally because a label
is unnecessary, not because the composition of the substance is a
secret.  It is almost always a matter of indifference to the owner of
an innocent substance whether another person who is legitimately in
possession of it and is entitled to examine it visually knows its
chemical composition as well.  /4/

   We recognize that it is possible to imagine a case in which a
person might legitimately wish to keep private the chemical
composition of a substance in his possession -- for example, if it is
a lawful drug that is used to treat mental illness.  Cf. Whalen v.
Roe, 429 U.S. 589, 599-602 (1977).  Even in such a case, however, a
chemical analysis can disclose only a limited, discrete piece of
information about a person.  It is not remotely as intrusive as a
search of a person's papers or effects.

   More important for purposes of this case, in most investigations of
illegal drug activity, it will be entirely clear to the authorities,
before they conduct any chemical analysis, that they are not dealing
with such a medically sensitive substance.  Lawful but medically
sensitive drugs are stored, shipped, packaged, and used in an entirely
different way from illicit substances.  No user of a medically
sensitive drug, for example, would package or ship it in the way in
which the cocaine involved here was sent to respondents.  In a case in
which there is a realistic possibility that the authorities are in
possession of a drug or other substance the composition of which a
person might legitimately wish to keep private, it might be
appropriate to require them to have some degree of particularized
suspicion before they conduct a chemical analysis.  /5/ But this is
not such a case.  /6/

   b. In any event, any privacy interests that might be affected by a
chemical analysis that reveals the precise composition of a substance
are not implicated in this case, because the field test the agents
performed was capable of determining only whether the substance
lawfully in their possession was in fact cocaine.  Had the substance
not been cocaine, the test would have revealed nothing else about it.
/7/ The test therefore could not have revealed any information at all
about an innocent substance, an innocent activity, or an innocent
person.  Because the field test could not have interfered with any
interest that is even arguably protected by the Fourth Amendment, it
cannot be regarded as a search within the meaning of the Amendment.

   The purpose of the Fourth Amendment is to protect against
unreasonable government intrusion into individuals' innocent private
affairs, not to give criminals greater security in their illicit
enterprises.  The Fourth Amendment regulates certain investigative
actions not because they uncover evidence of crime but because most
such actions, in the course of uncovering information concerning
illegal conduct, will unavoidably also reveal information about lawful
activity, or otherwise invade legitimate interests that the Fourth
Amendment protects.  Indeed, many investigative techniques -- such as
the surveillance of a person in a public place, or the monitoring of
an individual's conversations with a person whom he does not know to
be a government informer -- are unquestionably not searches even
though they reveal to the authorities much information that an
innocent person might well want to keep private.

   But the field test at issue here could not have disclosed any
information about lawful activity.  It was capable of revealing
information only about illegal conduct.  Nor did it in any other way
constitute an "'intrusion upon cherished personal security'" (Cupp v.
Murphy, 412 U.S. 291, 295 (1973), quoting Terry v. Ohio, supra, 392
U.S. at 24-25) or otherwise interfere with any interest arguably
protected by the Fourth Amendment.  There is, accordingly, no basis
for concluding that this technique is subject to the Fourth Amendment.
 When the authorities are able to obtain evidence of a crime without
infringing any legitimate private interest, it is simply irrational to
restrict their authority to do so by imposing procedural requirements
that cannot serve to protect significant individual rights.

   Of course, the purpose of the field test was to reveal information
about respondents' activities that they undoubtedly were eager to keep
private -- the fact that the substance discovered by the Federal
Express employees was cocaine.  But the desire to keep this
information from the authorities is perhaps the best example of a
privacy interest that society is not "prepared to recognize as
'reasonable'" (Katz v. United States, supra, 389 U.S. at 361 (Harlan,
J., concurring)).  Society has no reason at all to protect a person's
hope or expectation that his crime will escape detection, and that is
the only expectation that could possibly have been jeopardized by the
DEA agents' field test.  /8/ Cf. Roberts v. United States, 445 U.S.
552, 557-558 (1980);  Branzburg v. Hayes, 408 U.S. 665, 695-697
(1972);  pages 24-25, infra.

   Walter v. United States, 447 U.S. 649 (1980), far from supporting
the court of appeals' conclusion, is intructive in showing the court's
error.  Viewing a film discloses far more information that a person
has a legitimate interest in keeping private than conducting a
chemical analysis of a powder that is suspected of being a controlled
substance.  Viewing a film reveals much about the ideas and attitudes
of the person who made it, and about the interests and tastes of the
recipient.  See Stanley v. Georgia, 394 U.S. 557, 565 (1969);  Joseph
Burstyn, Inc. v. Wilson, 343 U.S. 495, 501 (1952).  This is true even
if, as in Walter, the contents of the film are described on its
container;  specific aspects of the film may reveal additional facts.
Partly for these reasons, the viewing of a film implicates the First
Amendment, which played a role in Walter.  See 447 U.S. at 655 & n.6
(opinion of Stevens, J.);  Roaden v. Kentucky, 413 U.S. 496, 502
(1973), quoting Coolidge v. New Hampshire, 403 U.S. 433, 472 (1971)
("The seizure of instruments of a crime, * * * or 'contraband * * * '
(is) to be distinguished from quantities of books and movie films when
a court appraises the reasonableness of the seizure under Fourth or
Fourteenth Amendment standards.").  A chemical analysis is incapable
of disclosing even remotely comparable information or of invading an
individual's privacy to a comparable degree, and there is no
justification for the court of appeals' ill-considered equation of the
viewing of a film with a chemical analysis.

   3. The court of appeals' holding that a chemical analysis requires
a warrant not only protects no legitimate privacy interest;  if the
court's approach were to prevail, it would impose extraordinary
burdens on the investigation of narcotics offenses.  Chemical analyses
are, obviously, often indispensable in deciding whether to pursue an
investigation further, as well as in proving a case against a person
charged with a drug offense.  As a result, law enforcement agents have
tested suspicious substances -- either in the field or in a laboratory
-- on innumerable occasions.

   In this case, the substance came into the agents' possession as the
result of the private search by Federal Express employees, but the
logic of the court of appeals' holding cannot be confined to such
cases.  The court of appeals would apparently rule that the government
conducts a search whenever it performs a test that "reveal(s) * * *
the composition of (a) powder" (Pet. App. 6a) unless, presumably, all
those able to claim an interest in the powder have relinquished their
claim to keep its composition secret.  Thus, under the court of
appeals' ruling, law enforcement agents would certainly have to seek a
warrant every time they wished to conduct a test on a substance
obtained through a warrantless search -- such as a probable cause
search of a vehicle or a search incident to arrest, which are both
common means of uncovering illicit drugs.  The authorities might also
have to seek a second warrant every time they wished to test a
substance seized pursuant to a search warrant that did not
specifically authorize a chemical analysis.

   As a result, under the court of appeals' approach, law enforcement
agents would have to obtain literally thousands of additional warrants
each year.  This massive burden on law enforcement and judicial
resources is itself good reason to hesitate before imposing a warrant
requirement.  In addition, many investigations that could be aided by
a chemical analysis would be impaired, either because the agents
lacked probable cause or because they could not afford to expend the
time and effort needed to obtain a warrant.  And these costs would be
incurred even though there is no offsetting benefit to legitimate
privacy interests.

   Although the results of chemical analyses have been used in
countless narcotics prosecutions in the past, we know of no other
court that has ever suggested that the warrant is required before the
government may undertake a chemical analysis.  On the contrary, every
other court of appeals has rejected, either expressly or by
implication, the view that a chemical analysis requires a warrant.
See, e.g., United States v. Barry, 673 F.2d 912 (6th Cir. 1982), cert.
denied, No. 81-6942 (Oct. 12, 1982);  United States v. Russell, 655
F.2d 1261, 1263-1264 (D.C. Cir. 1981), modified on other grounds, 670
F.2d 323, cert. denied, 457 U.S. 1108 (1982);  United States v.
Jennings, 653 F.2d 107, 108 (4th Cir. 1981);  United States v.
Walther, 652 F.2d 788, 790 (9th Cir. 1981);  United States v.
Williams, 622 F.2d 830, 834 & n.8, 839 (5th Cir. 1980) (en banc),
cert. denied, 449 U.S. 1127 (1981);  United States v. Andrews, 618
F.2d 646 (10th Cir.), cert. denied, 449 U.S. 824 (1980);  United
States v. Bulgier, 618 F.2d 472, 474 (7th Cir.), cert. denied, 449
U.S. 843 (1980);  United States v. Nieves, 609 F.2d 642, 644, 647-648
(2d Cir. 1979), cert. denied, 444 U.S. 1085 (1980);  United States v.
Edwards, 602 F.2d 458 (1st Cir. 1979);  United States v. Rodriguez,
596 F.2d 169, 173-175 (6th Cir. 1979);  United States v. Belle, 593
F.2d 487, 491, 499-500 (3d Cir.) (en banc), cert. denied, 442 U.S. 911
(1979);  United States v. Crabtree, 545 F.2d 884 (4th Cir. 1976);
United States v. Ford, 525 F.2d 1308, 1312 (10th Cir. 1975).  See also
People v. Adler, 50 N.Y.2d 730, 732 n.4, 409 N.E.2d 888, 891 n.4, 431
N.Y.S.2d 412, 416 n.4, cert. denied, 449 U.S. 1014 (1980).

 B. The Actions Taken By the Agents Preparatory To the Chemical
Analysis Did Not Violate the Fourth Amendment

   Although the principal basis of the court of appeals' holding was
its conclusion that the chemical analysis was a search requiring a
warrant, respondents suggest (Br. in Opp. 6-8) that the agents also
violated the Fourth Amendment when they took other actions preparatory
to performing the analysis -- such as removing the plastic bags from
the box, or extracting samples from the plastic bags in order to
perform the test.  /9/ In fact, none of the actions leading up to the
field test even arguably infringed any interest protected by the
Fourth Amendment.

   1. There is no doubt that the DEA agents lawfully came into
possession of the package that had been sent to respondents.  The
initial search of the package was conducted by private Federal Express
employees.  The Fourth Amendment does not apply to private searches
(Burdeau v. McDowell, 256 U.S. 465, 475 (1921)), and respondents have
never contended that the government was implicated in the Federal
Express employees' inspection of the package.  The Federal Express
employees, having inspected the package, invited the DEA agents to
view its contents;  the Fourth Amendment did not prohibit the agents
from doing so.  See Coolidge v. New Hampshire, supra, 403 U.S. at
487-490;  Burdeau v. McDowell, supra, 256 U.S. at 475-476.  /10/

   2. After they were given the partially repacked container by
Federal Express, the agents removed the transparent plastic bags
containing the white powder from the taped tube.  This action, too,
was plainly lawful.  The court of appeals stated that when the agents
first saw the package the bags were visible from the end of the tube.
Pet. App. 1a.  If this statement is correct, then the Federal Express
employees had "exposed (the bags) to plain view" and "'it was not
incumbent on the (agents) to * * * avert their eyes.'" Walter v.
United States, supra, 447 U.S. at 661 (opinion of White, J.), quoting
Coolidge v. New Hampshire, supra, 403 U.S. at 489.  That is, the
removal of the bags from the tube did not expose anything to the
agents' view that the Federal Express employees had not already made
visible to them.

   Respondents dispute the court of appeals' factual statement;  they
assert that the Federal Express employees had repacked the package in
such a way that, when they turned it over to the DEA agents, the
plastic bags were not visible.  Br. in Opp. 6.  /11/ But as
respondents and the court of appeals apparently acknowledge, nothing
should turn on this factual disagreement.  It is not disputed that the
Federal Express employees inspected the package completely, removing
the plastic bags from the tube and examining them, before they
repacked it.  Thus when the agents removed the bags from the package,
they did not exceed the scope of the private search.  Both the court
of appeals and respondents seem to accept the principle that
government officials have not conducted a search within the meaning of
the Fourth Amendment if they do not exceed the scope of a previous
private search, no matter what condition the package is in when it is
delivered to the government.  See Pet. App. 5a-6a;  Br. in Opp. 6
("This case * * * involves whether Government agents may extend the
scope of a search which has already been conducted by private
parties.").

   This principle also appears to have been endorsed by a majority of
this Court (see Walter v. United States, supra, 447 U.S. at 656, 659
n.14 (opinion of Stevens, J.);  id. at 663 (Blackmun, J.,
dissenting)), /12/ and its application in this case is clearly sound.
The Federal Express employees, whose actions were at all times lawful,
summoned the DEA agents for the specific purpose of showing them the
plastic bags containing the white powder.  The employees might have
chosen to leave the bags in full view while awaiting the DEA agents'
arrival;  or, when the agents arrived, the Federal Express employees
might have removed the bags again to show the agents why they had been
called.  In either event the removal of the bags would have raised no
Fourth Amendment question whatever.  Instead, the employees apparently
explained to the agents the reason they had been called and invited
the agents to remove the bags that the employees had already once
removed.  These differences in the precise sequence of events cannot
be constitutionally significant.  /13/

   3. After removing the plastic bags from the tube, the agents opened
them in order to obtain a sample for testing.  It is entirely clear
that opening a transparent container does not constitute a search
requiring a warrant.  The Court has specifically so ruled:

         Not all containers and packages * * * will deserve the full
      protection of the Fourth Amendment.  Thus, some containers (for
      example a kit of burglar tools or a gun case) by their very
      nature cannot support any reasonable expectation of privacy
      because their contents can be inferred from their outward
      appearance.  Similarly, in some cases the contents of a package
      will be open to "plain view," thereby obviating the need for a
      warrant.

   Arkansas v. Sanders, 442 U.S. 753, 764-765 n.13 (1979).  A
transparent bag is surely the archetype of a container the contents of
which can be "inferred from (its) outward appearance";  indeed, those
contents were in plain view once the officers lawfully saw the plastic
container.  Opening the container therefore could not have infringed
any interest protected by the Fourth Amendment.

   4. Finally, the agents removed a small portion of the cocaine in
order to test it, and this cocaine was consumed in the test.  These
acts were not in any sense a search, because they did not reveal
anything that was not already in plain view or otherwise interfere
with any privacy interest.  See, e.g., Texas v. Brown, No. 81-419
(Apr. 19, 1983), slip op. 7-8 (plurality opinion);  United States v.
Lisk, 522 F.2d 228, 230 (7th Cir. 1975) (Stevens, J.), cert. denied,
423 U.S. 1078 (1976).  At most, these actions might be characterized
as a seizure of a few particles of the substance.  But neither
respondents nor the court of appeals appears to have asserted that the
removal and destruction of a few particles was an illegal seizure, and
it plainly was not.

   First, the agent who performed the test described the quantity
involved as "a trace amount" that was much less than a gram (J.A. 75);
 the retention or destruction of such a small amount of a substance is
de minimis.  See generally, Cardwell v. Lewis, 417 U.S. 583, 591
(1974) (plurality opinion);  United States v. Van Lewuwen, 397 U.S.
249 (1970).  Second, it is well established that when contraband is
involved, the government violates no interest protected by either the
common law (see, e.g., Warden v. Hayden, 387 U.S. 294, 303-304 (1967))
or the Constitution when it engages in what would otherwise be a
trespass to chattels.  See, e.g., Boyd v. United States, 116 U.S. 616,
623-624 (1886);  United States v. Washington, 586 F.2d 1147, 1154 (7th
Cir. 1978);  United States v. Pringle, 576 F.2d 1114, 1119 (5th Cir.
1978);  United States v. Emery, 541 F.2d 887, 890 (1st Cir. 1976).

   Finally, even if the retention or destruction of a small amount of
the cocaine was a seizure, the Fourth Amendment permits seizures upon
probable cause without a warrant.  E.g., Texas v. Brown, supra, slip
op. 8 (plurality opinion) ("(O)our decisions have come to reflect the
rule that if, while lawfully engaged in an activity in a particular
place, police officers perceive a suspicious object, they may seize it
immediately.");  id. at 2 (Stevens, J., concurring in the judgment);
Payton v. New York, 445 U.S. 573, 587 (1980);  G.M. Leasing Corp. v.
United States, 429 U.S. 338, 354 (1977).  A seizure that works such a
minimal intrusion can surely be justified on the basis of reasonable
suspicion not amounting to probable cause.  See Terry v. Ohio, supra;
United States v. Van Leeuwen, supra, 397 U.S. at 252-253;  cf. United
States v. Place, 660 F.2d 44 (2d Cir. 1981), cert. granted, No.
81-1617 (argued Mar. 2, 1983).  Here, moreover, it seems beyond
serious dispute that there was probable cause.  It is unquestioned
that the powder had the appearance of cocaine, and it is most unlikely
that any lawful white powdered substance would have been shipped in
such a way.  /14/ Thus the agents had far more than the quantum of
suspicion they needed to make any "seizure" that was involved in
removing a few grains of the powder for testing.  /15/

                              CONCLUSION

   The judgment of the court of appeals should be reversed.

   Respectfully submitted.

   REX E. LEE

      Solicitor General

   D. LOWELL JENSEN

      Assistant Attorney General

   ANDREW L. FREY

      Deputy Solicitor General

   DAVID A. STRAUSS

      Assistant to the Solicitor General

   JOEL M. GERSHOWITZ

      Attorney

   JUNE 1983

   /1/ Respondent Bradley Jacobsen was sentenced to a term of one
year's imprisonment and three years' special parole on the substantive
narcotics count, a consecutive term of six months' imprisonment on the
assault count, and a concurrent term of one year's imprisonment on the
conspiracy count.  Respondent Donna Jacobsen was sentenced to a
one-year term of imprisonment and a three-year special parole term on
the substantive count, and a concurrent one-year prison term on the
conspiracy count, but her sentences were suspended and she was placed
on three years' probation on the condition that she serve three months
in a jail-type facility.  Pet. App. 3a n.1.

   /2/ The court of appeals affirmed Bradley Jacobsen's assault
conviction (Pet. App. 8a).

   /3/ "Tr." refers to the trial transcript.

   /4/ To the extent that the court of appeals' rationale depends upon
the supposed impropriety of investigation "by using mechanical or
chemical means to discover the hidden nature of the objects" (Pet.
App. 6a), it would not require law enforcement agents to obtain a
warrant before they "analyzed" a substance by tasting it or inhaling
it in the way that a user of cocaine would inhale it.  But such a
"test" is only a somewhat less reliable (and obviously less desirable)
means of identifying the chemical content of a substance.

   /5/ Even in such a case, we see no sufficient justification for
requiring probable cause, and certainly no basis for a warrant
requirement.  First, as we noted, because a chemical analysis can
disclose, at most, only a narrow piece of information, it is not
nearly as intrusive as a search of a person's papers or effects.
Second, any lawful drug or chemical of a sensitive nature will, in all
probability, already be subject to extensive government regulation;
the fact that a particular individual possesses it will, therefore,
already be known to others and may be accessible to the government in
appropriate circumstances.  Cf. United States v. Miller, 425 U.S. 435
(1976).  Third, before law enforcement officers can conduct a chemical
analysis of a substance, they must have lawfully obtained possession
of it.  Any expectation of privacy will, therefore, already have been
compromised to a substantial degree before the analysis is conducted.
Finally, it is unlikely that a warrant requirement will provide any
significant additional protection in these circumstances.  In general,
a law enforcement officer must seek a warrant when he is confronted
with the question whether a variety of complex facts amount to
probable cause to believe that criminal activity is afoot.  It will
generally be far easier for an officer to decide whether a particular
substance, already in his possession, is probably contraband.

   /6/ Moreover, the DEA agents had abundant affirmative grounds to
believe that they were dealing with an unlawful drug in this case (see
pages 25-26 and note 15, infra).

   /7/ At trial, the agent who conducted the field test described it
as "a Scott reagent field test * * * for cocaine" (J.A. 72) and
briefly explained its operation.  The DEA informs us that this test
will reveal only whether or not a substance is cocaine;  if it is not
cocaine, the test will not reveal its composition.  This fact was not
brought out at the suppression hearing or the trial, because neither
focused on the precise nature of the test.  But the court of appeals
did not suggest that it believed that the test revealed more than
whether a substance is cocaine, and the court of appeals' holding does
not rest on the premise that the test would reveal any other
information.

   /8/ We do not deny that there is an important sense in which the
Fourth Amendment "protects the guilty as well as the innocent":  law
enforcement officers who comply with the Fourth Amendment will
sometimes lack the quantum of suspicion needed to conduct a search
that would, in fact, have revealed evidence of a crime, and as a
result a guilty person will escape detection.  But this benefit to the
guilty is simply an unavoidable byproduct of the protection that the
Fourth Amendment affords to the innocent.  It does not mean that the
Framers of the Amendment intended to give guilty persons a "right" to
avoid detection.  The rights of innocent persons can be adequately
protected only if insufficiently supported searches are proscribed
before they are even conducted, at a time when it is impossible to be
certain whether the search will uncover evidence of crime;  as a
result, some guilty parties must, unfortunately but unavoidably,
escape detection if the Amendment is to protect the innocent.

   This case, however, involves an investigative technique that cannot
possibly intrude on the rights of the innocent;  it can invade a
"privacy" interest only of a person engaged in criminal activity.  It
is obviously unreasonable to restrict the use of such a technique in
the ways that techniques that could invade the privacy interests of
innocent persons may appropriately be restricted.

   /9/ At one point the court of appeals remarked (Pet. App. 8a):  "We
find that the agents' removal of the plastic bags, the taking of
samples, and the chemical analysis of these samples constituted a
violation of (respondents') fourth amendment rights." But it seems
plain that the court of appeals' primary concern was with the chemical
analysis itself, which the court equated to the viewing of a film.
See id. at 6a, 7a n.4.

   /10/ In addition, the private inspection was required by the
standard policies of Federal Express, as was the call to DEA when a
suspicious substance was discovered.  Pet. App. 17a;  J.A. 46.  While
the courts below did not inquire into the precise terms of the
bailment between Federal Express and the person who sent the cocaine
to respondents, respondents have never suggested that the Federal
Express employees' inspection of the package was tortious or otherwise
improper.

   /11/ This factual question was not resolved by the district court,
because it correctly viewed the point as "immaterial to the legal
issue presented here." Pet. App. 12a-13a.

   /12/ See also United States v. Bulgier, supra, 618 F.2d at 474;
United States v. McDaniel, 574 F.2d 1224, 1226-1227 (5th Cir. 1978),
cert. denied, 441 U.S. 952 (1979);  United States v. Pryba, 502 F.2d
391, 401 (D.C. Cir. 1974), cert. denied, 419 U.S. 1127 (1975);  United
States v. Blanton, 479 F.2d 327, 328 (5th Cir. 1973).

   /13/ For these reasons, the question presented by the agents'
removal of the plastic bags is different from the hypothetical issue
discussed by some of the opinions in Walter -- "whether the
Government's projection of (lawfully seized) * * * films would * * *
infringe() any Fourth Amendment interest if private parties had
projected the films before turning them over to the Government" (447
U.S. at 660 (opinion of White, J.)).  This is not a case in which the
government has simply duplicated a private party's earlier invasion of
privacy interests;  here, the private party specifically invited the
government to view the fruits of its lawful private search.  The
precise mechanism by which the private party makes those fruits
available to the government should not be significant for Fourth
Amendment purposes.

   Indeed, once Federal Express employees had opened the package and
inspected the plastic bags, the DEA agents could have asked Federal
Express to bring the plastic bags to DEA headquarters without
infringing any privacy interest -- even if Federal Express had, in the
meantime, repacked the package to some degree.  The government could
even have subpoenaed the bags when they were in the possession of
Federal Express, even if the package had been repacked, without
invading any protected privacy interest of respondents.  See Burdeau
v. McDowell, supra, 256 U.S. at 476.  In these circumstances, the
agents' decision simply to go to the Federal Express office and obtain
the bags themselves cannot be said to have invaded any protected
interest.

   /14/ See Texas v. Brown, supra, slip op. 3 (Powell, J., concurring
in the judgment) ("We are not advised of any innocent item that is
commonly carried in (an) uninflated, tied-off balloon").

   /15/ The court of appeals' apparent holding (Pet. App. 8a) that
there was no probable cause until the field test had been performed is
therefore obviously incorrect.  This holding appears to have been
unconsidered and probably unintended.  Indeed, it would lead the court
of appeals to the absurd conclusion that the agents were helpless to
do anything to interdict the shipment of cocaine or to apprehend
respondents, since on the court of appeals' view the agents, lacking
probable cause, could never have obtained the warrant the court held
they needed to conduct the field test.

   Because the court of appeals erred in ruling that the agents lacked
probable cause independent of the field test, the evidence obtained in
the search of respondents' house (pursuant to the warrant) was not
"tainted" by the field test.  Thus, even accepting the court of
appeals' conclusion that a warrant was needed before the field test
could be conducted, that court erred in ordering the suppression of
the evidence obtained from the house and the reversal of respondents'
narcotics convictions.