JUSTICE STEVENS delivered the opinion of the Court.
During their examination of a damaged package, the employees of a private freight carrier observed a white powdery substance, originally concealed within eight layers of wrappings. They summoned a federal agent, who removed a trace of the powder, subjected it to a chemical test and determined that it was cocaine. The question presented is whether the Fourth Amendment required the agent to obtain a warrant before he did so.
The relevant facts are not in dispute. Early in the morning of May 1, 1981, a supervisor at the Minneapolis-St. Paul Airport Federal Express office asked the office manager to look at a package that had been damaged and torn by a forklift. They then opened the package in order to examine its contents pursuant to a written company policy regarding insurance claims.
The container was an ordinary cardboard box wrapped in brown paper. Inside the box five or six pieces of crumpled newspaper covered a tube about 10 inches long; the tube was made of the silver tape used on basement ducts. The supervisor and office manager cut open the tube and found a series of four zip-lock plastic bags, the outermost enclosing the other three and the innermost containing about six and a half ounces of white powder. When they observed the white powder in the innermost bag, they notified the Drug Enforcement Administration. Before the first DEA agent arrived, they replaced the plastic bags in the tube and put the tube and the newspapers back into the box.
When the first federal agent arrived, the box, still wrapped in brown paper, but with a hole punched in its side and the top open, was placed on a desk. The agent saw that one end of the tube had been slit open; he removed the four plastic bags from the tube and saw the white powder. He then opened each of the four bags and removed a trace of the white substance with a knife blade. A field test made on the spot identified the substance as cocaine.
In due course, other agents arrived, made a second field test, rewrapped the package, obtained a warrant to search the place to which it was addressed, executed the warrant, and arrested respondents. After they were indicted for the crime of possessing an illegal substance with intent to distribute, their motion to suppress the evidence on the ground that the warrant was the product of an illegal search and seizure was denied; they were tried and convicted, and appealed. The Court of Appeals reversed. It held that the validity of the search warrant depended on the validity of the agents’ warrantless test of the white powder, that the testing constituted a significant expansion of the earlier private search, and that a warrant was required.
As the Court of Appeals recognized, its decision conflicted with a decision of another Court of Appeals on comparable facts. For that reason, and because field tests play an important role in the enforcement of the narcotics laws, we granted certiorari.
The first Clause of the Fourth Amendment provides that the
“right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated. . . .”
This text protects two types of expectations, one involving “searches,” the other “seizures.” A “search” occurs when an expectation of privacy that society is prepared to consider reasonable is infringed. A “seizure” of property occurs when there is some meaningful interference with an individual’s possessory interests in that property. This Court has also consistently construed this protection as proscribing only governmental action; it is wholly inapplicable
“to a search or seizure, even an unreasonable one, effected by a private individual not acting as an agent of the Government or with the participation or knowledge of any governmental official.”
When the wrapped parcel involved in this case was delivered to the private freight carrier, it was unquestionably an “effect” within the meaning of the Fourth Amendment. Letters and other sealed packages are in the general class of effects in which the public at large has a legitimate expectation of privacy; warrantless searches of such effects are presumptively unreasonable. Even when government agents may lawfully seize such a package to prevent loss or destruction of suspected contraband, the Fourth Amendment requires that they obtain a warrant before examining the contents of such a package. Such a warrantless search could not be characterized as reasonable simply because, after the official invasion of privacy occurred, contraband is discovered. Conversely, in this case, the fact that agents of the private carrier independently opened the package and made an examination that might have been impermissible for a government agent cannot render otherwise reasonable official conduct unreasonable. The reasonableness of an official invasion of the citizen’s privacy must be appraised on the basis of the facts as they existed at the time that invasion occurred.
The initial invasions of respondents’ package were occasioned by private action. Those invasions revealed that the package contained only one significant item, a suspicious looking tape tube. Cutting the end of the tube and extracting its contents revealed a suspicious looking plastic bag of white powder. Whether those invasions were accidental or deliberate, and whether they were reasonable or unreasonable, they did not violate the Fourth Amendment because of their private character.
The additional invasions of respondents’ privacy by the Government agent must be tested by the degree to which they exceeded the scope of the private search. That standard was adopted by a majority of the Court in Walter v. United States. In Walter, a private party had opened a misdirected carton, found rolls of motion picture films that appeared to be contraband, and turned the carton over to the Federal Bureau of Investigation. Later, without obtaining a warrant, FBI agents obtained a projector and viewed the films. While there was no single opinion of the Court, a majority did agree on the appropriate analysis of a governmental search which follows on the heels of a private one. Two Justices took the position:
“If a properly authorized official search is limited by the particular terms of its authorization, at least the same kind of strict limitation must be applied to any official use of a private party’s invasion of another person’s privacy. Even though some circumstances—for example, if the results of the private search are in plain view when materials are turned over to the Government—may justify the Government’s reexamination of the materials, surely the Government may not exceed the scope of the private search unless it has the right to make an independent search. In these cases, the private party had not actually viewed the films. Prior to the Government screening, one could only draw inferences about what was on the films. The projection of the films was a significant expansion of the search that had been conducted previously by a private party, and therefore must be characterized as a separate search.”
Four additional Justices, while disagreeing with this characterization of the scope of the private search, were also of the view that the legality of the governmental search must be tested by the scope of the antecedent private search.
“Under these circumstances, since the L’Eggs employees so fully ascertained the nature of the films before contacting the authorities, we find that the FBI’s subsequent viewing of the movies on a projector did not change the nature of the search,’ and was not an additional search subject to the warrant requirement.”
This standard follows from the analysis applicable when private parties reveal other kinds of private information to the authorities. It is well settled that, when an individual reveals private information to another, he assumes the risk that his confidant will reveal that information to the authorities, and if that occurs, the Fourth Amendment does not prohibit governmental use of that information. Once frustration of the original expectation of privacy occurs, the Fourth Amendment does not prohibit governmental use of the now nonprivate information:
“This Court has held repeatedly that the Fourth Amendment does not prohibit the obtaining of information revealed to a third party and conveyed by him to Government authorities, even if the information is revealed on the assumption that it will be used only for a limited purpose and the confidence placed in a third party will not be betrayed.”
The Fourth Amendment is implicated only if the authorities use information with respect to which the expectation of privacy has not already been frustrated. In such a case, the authorities have not relied on what is in effect a private search, and therefore presumptively violate the Fourth Amendment if they act without a warrant.
In this case, the federal agents’ invasions of respondents’ privacy involved two steps: first, they removed the tube from the box, the plastic bags from the tube, and a trace of powder from the innermost bag; second, they made a chemical test of the powder. Although we ultimately conclude that both actions were reasonable for essentially the same reason, it is useful to discuss them separately.
When the first federal agent on the scene initially saw the package, he knew it contained nothing of significance except a tube containing plastic bags and, ultimately, white powder. It is not entirely clear that the powder was visible to him before he removed the tube from the box. Even if the white powder was not itself in “plain view” because it was still enclosed in so many containers and covered with papers, there was a virtual certainty that nothing else of significance was in the package and that a manual inspection of the tube and its contents would not tell him anything more than he already had been told. Respondents do not dispute that the Government could utilize the Federal Express employees’ testimony concerning the contents of the package. If that is the case, it hardly infringed respondents’ privacy for the agents to reexamine the contents of the open package by brushing aside a crumpled newspaper and picking up the tube.
The advantage the Government gained thereby was merely avoiding the risk of a flaw in the employees’ recollection, rather than in further infringing respondents’ privacy. Protecting the risk of misdescription hardly enhances any legitimate privacy interest, and is not protected by the Fourth Amendment. Respondents could have no privacy interest in the contents of the package, since it remained unsealed and since the Federal Express employees had just examined the package and had, of their own accord, invited the federal agent to their offices for the express purpose of viewing its contents. The agent’s viewing of what a private party had freely made available for his inspection did not violate the Fourth Amendment.
Similarly, the removal of the plastic bags from the tube and the agent’s visual inspection of their contents enabled the agent to learn nothing that had not previously been learned during the private search. It infringed no legitimate expectation of privacy, and hence was not a “search” within the meaning of the Fourth Amendment.
While the agents’ assertion of dominion and control over the package and its contents did constitute a “seizure,” that seizure was not unreasonable. The fact that, prior to the field test, respondents’ privacy interest in the contents of the package had been largely compromised is highly relevant to the reasonableness of the agents’ conduct in this respect. The agents had already learned a great deal about the contents of the package from the Federal Express employees, all of which was consistent with what they could see. The package itself, which had previously been opened, remained unsealed, and the Federal Express employees had invited the agents to examine its contents. Under these circumstances, the package could no longer support any expectation of privacy; it was just like a balloon “the distinctive character of which spoke volumes as to its contents—particularly to the trained eye of the officer.” Such containers may be seized, at least temporarily, without a warrant. Accordingly, since it was apparent that the tube and plastic bags contained contraband and little else, this warrantless seizure was reasonable, for it is well settled that it is constitutionally reasonable for law enforcement officials to seize “effects” that cannot support a justifiable expectation of privacy without a warrant, based on probable cause to believe they contain contraband.
The question remains whether the additional intrusion occasioned by the field test, which had not been conducted by the Federal Express employees and therefore exceeded the scope of the private search, was an unlawful “search” or “seizure” within the meaning of the Fourth Amendment.
The field test at issue could disclose only one fact previously unknown to the agent—whether or not a suspicious white powder was cocaine. It could tell him nothing more, not even whether the substance was sugar or talcum powder. We must first determine whether this can be considered a “search” subject to the Fourth Amendment— did it infringe an expectation of privacy that society is prepared to consider reasonable?
The concept of an interest in privacy that society is prepared to recognize as reasonable is, by its very nature, critically different from the mere expectation, however well justified, that certain facts will not come to the attention of the authorities. Indeed, this distinction underlies the rule that government may utilize information voluntarily disclosed to a governmental informant, despite the criminal’s reasonable expectation that his associates would not disclose confidential information to the authorities.
A chemical test that merely discloses whether or not a particular substance is cocaine does not compromise any legitimate interest in privacy. This conclusion is not dependent on the result of any particular test. It is probably safe to assume that virtually all of the tests conducted under circumstances comparable to those disclosed by this record would result in a positive finding; in such cases, no legitimate interest has been compromised. But even if the results are negative—merely disclosing that the substance is something other than cocaine—such a result reveals nothing of special interest. Congress has decided—and there is no question about its power to do so—to treat the interest in “privately” possessing cocaine as illegitimate; thus governmental conduct that can reveal whether a substance is cocaine, and no other arguably “private” fact, compromises no legitimate privacy interest.
This conclusion is dictated by United States v. Place, in which the Court held that subjecting luggage to a “sniff test” by a trained narcotics detection dog was not a “search” within the meaning of the Fourth Amendment:
“A ‘canine sniff’ by a well-trained narcotics detection dog, however, does not require opening the luggage. It does not expose noncontraband items that otherwise would remain hidden from public view, as does, for example, an officer’s rummaging through the contents of the luggage. Thus, the manner in which information is obtained through this investigative technique is much less intrusive than a typical search. Moreover, the sniff discloses only the presence or absence of narcotics, a contraband item. Thus, despite the fact that the sniff tells the authorities something about the contents of the luggage, the information obtained is limited.”
Here, as in Place, the likelihood that official conduct of the kind disclosed by the record will actually compromise any legitimate interest in privacy seems much too remote to characterize the testing as a search subject to the Fourth Amendment.
We have concluded that the initial “seizure” of the package and its contents was reasonable. Nevertheless, as Place also holds, a seizure lawful at its inception can nevertheless violate the Fourth Amendment because its manner of execution unreasonably infringes possessory interests protected by the Fourth Amendment’s prohibition on “unreasonable seizures.” Here, the field test did affect respondents’ possessory interests protected by the Amendment, since, by destroying a quantity of the powder, it converted what had been only a temporary deprivation of possessory interests into a permanent one. To assess the reasonableness of this conduct, “we must balance the nature and quality of the intrusion on the individual’s Fourth Amendment interests against the importance of the governmental interests alleged to justify the intrusion.”
Applying this test, we conclude that the destruction of the powder during the course of the field test was reasonable. The law enforcement interests justifying the procedure were substantial; the suspicious nature of the material made it virtually certain that the substance tested was in fact contraband. Conversely, because only a trace amount of material was involved, the loss of which appears to have gone unnoticed by respondents, and since the property had already been lawfully detained, the “seizure” could, at most, have only a de minimis impact on any protected property interest. Under these circumstances, the safeguards of a warrant would only minimally advance Fourth Amendment interests. This warrantless “seizure” was reasonable.
In sum, the federal agents did not infringe any constitutionally protected privacy interest that had not already been frustrated as the result of private conduct. To the extent that a protected possessory interest was infringed, the infringement was de minimis and constitutionally reasonable. The judgment of the Court of Appeals is
Modification History File Created: 08/10/2018 Last Modified: 08/10/2018