SEARCH AND SEIZURE

The fourth amendment has the virtue of brevity and the vice of ambiguity. It does not define the probable cause required for warrants or indicate whether a warrantless search or seizure is inevitably "unreasonable" if made without probable cause, so that the factual basis required for a constitutional search or seizure is unclear. The amendment does not define the relationship of the word "unreasonable" to the clause setting forth the conditions under which warrants may issue; it is thus unclear when a judicial officer's approval must be obtained before an arrest or search is made. There is also uncertainty as to what official conduct is subject to the amendment's restraints, that is, just what actions amount to "searches and seizures" and threaten the "right of the people to be secure." Finally, there is ambiguity concerning how that right is to be enforced; unlike the Fifth Amendment right against self-incrimination, no mention is made of barring from evidence the fruits of a violation of the amendment. The Supreme Court has had to respond to each of these four fundamental questions. (See right-privilege distinction.)

The warrant clause of the Fourth Amendment makes it apparent that a valid arrest warrant or search warrant may issue only upon a showing of probable cause to the issuing authority. This requirement is intended to prohibit resort to general warrants and arrest and search on suspicion. As the Court noted in brinegar v. united states (1949), it is also intended "to give fair leeway for enforcing the law in the community's protection," and thus is best perceived as "a practical, nontechnical conception affording the best compromise that has been found for accommodating these often opposing interests" of individual privacy and collective security.

Though a literal reading of the Fourth Amendment does not compel this result, the prohibition upon " unreasonable " searches and seizures has been construed to mean that even searches and seizures conducted without a warrant require probable cause. As explained in wong sun v. united states (1963), "the requirements of reliability and particularity of the information on which an officer may act … surely cannot be less stringent [when an arrest is made without a warrant] than where an arrest warrant is obtained. Otherwise, a principal incentive now existing for the procurement of arrest warrants would be destroyed." But the amount of probable cause required for with-warrant and without-warrant searches is not exactly the same; the Court stated in United States v. Ventresca (1965) that because of the preference accorded to warrants, "in a doubtful or marginal case a search under a warrant may be sustainable where without one it would fail."

The same quantum of evidence is required whether one is concerned with probable cause to arrest or to search. Thus in spinelli v. united states (1969), concerning probable cause for a search warrant, the Court found its earlier decision in draper v. united states (1959), concerning probable cause to arrest, to be a "suitable benchmark." But the arrest and search situations differ in important respects. For arrest, it must be sufficiently probable that an offense has been committed and that the particular individual to be arrested has committed it; for a search, it must be sufficiently probable that specified items are evidence of criminal activity and are to be found in the specified place. On a given set of facts one type of probable cause may be present but not the other.

The probable cause test is an objective rather than a subjective one. "If subjective good faith alone were the test," the Supreme Court said in Beck v. Ohio (1964), "the protections of the Fourth Amendment would evaporate, and the people would be 'secure in their houses, papers, and effects,' only in the discretion of the police." The question, therefore, is not what the arresting or searching officer thought but rather what a reasonable person with the experience and expertise of the officer would have thought. That assessment is to be made on all available information regardless of its admissibility in a criminal trial because, as the Court said in Brinegar, the probable cause test is "not technical" and involves "the factual and practical considerations of everyday life on which reasonable and prudent men, not legal technicians, act." Thus credible hearsay may be considered, but a person's reputation, at least when stated in terms of unsubstantiated conclusions, cannot.

Although Brinegar declares that probable cause requires "less than evidence which would justify … conviction" but yet "more than bare suspicion" and also that the question is one of "probabilities," it gives no indication as to what degree of probability is required. Some of the Court's decisions—for example, Johnson v. United States (1948), holding that the smell of burning opium from within a hotel room did not amount to probable cause to arrest a particular occupant because until the subsequent entry she was not known to be the sole occupant of the room—suggest a more-probable-than-not standard. But the Supreme Court has never explicitly held that the Fourth Amendment requires this standard, and the lower courts have understandably found such an interpretation too stringent in at least some circumstances. Thus, it is not uncommon to find an appellate decision holding that an arrest near a crime scene was lawful even though the victim's description was not exact or detailed enough to single the arrested person out from all other persons in the vicinity, or that a search of a number of different places under a suspect's control is permissible even though no one of them is the more-probable-than-not location of the evidence sought.

Most of the Supreme Court's probable cause cases involve information from police informants, denizens of the criminal milieu who provide information in exchange for money or informal immunity regarding their own criminal conduct. In aguilar v. texas (1964), where the search warrant affidavit merely recited that the affiants had "received reliable information from a credible person" that "narcotics and narcotics paraphernalia are being kept at the above described premises," the Court adopted a two-pronged test. This affidavit was held insufficient because, first, it did not disclose how the informant knew what he claimed to know concerning what was in the house; and second, it did not disclose how the affiants concluded that their informer was reliable. The first prong of this test has usually been met with details about how the informant acquired his knowledge (for instance, that he had just been inside the house and saw there a cache of narcotics from which the occupant made a sale), though it can be indirectly satisfied by self-verifying detail. As explained in Spinelli, if the informant gives a great many details about the criminal scheme (the precise amount of narcotics in the house, how it is wrapped, exactly where it is stored), then it may be inferred "that the informant had gained his information in a reliable way."

The second or "veracity" prong of Aguilar has typically been met on the basis of past performance, that is, by a recitation that this same informant previously has given information that turned out to be correct. Alternatively, it has sufficed to show, as in united states v. harris (1971), that the informant's statement included an admission against penal interest ("I bought some narcotics while I was in that house"), as people "do not lightly admit a crime and place critical evidence in the hands of the police in the form of their own admissions." The Supreme Court sometimes stressed that the informer's tale was partly corroborated, but there was considerable uncertainty as to just what deficiencies under the Aguilar twopronged test this corroboration overcomes. (Because the use of informants raises special concerns not present in other situations, no comparable showing of veracity is needed when the information has been obtained from a police officer or a cooperative citizen.)

The Aguilar test was abandoned in illinois v. gates (1983) in favor of a more general "totality of the circumstances" approach. The Aguilar factors of veracity and basis of knowledge remain as "relevant considerations," but are no longer two independent requirements; "a deficiency in one may be compensated for … by a strong showing as to the other." This is an unfortunate development, for the Aguilar rule provided a necessary structure and more precise guidance to police and judges. Moreover, the Gates approach is unsound, for surely—as the Court has often held—a conclusory allegation ("there are narcotics in that house") is insufficient even when it comes from a source of unquestioned reliability. Gates will doubtless make it easier to establish probable cause than it has been previously; the Court deemed it sufficient that the police had received an anonymous letter with a conclusory assertion of drug trafficking and then had corroborated the letter with certain predicted behavior that was not otherwise suspicious.

One extremely important question regarding the Fourth Amendment probable cause test is whether it is fixed or variable, that is, whether it always requires the same quantum of evidence or whether this compromise between privacy and law enforcement interests may be struck differently on a case-by-case basis. For example, may it be concluded that the solution of an unsolved murder is of greater public concern than the solution of an unsolved shoplifting, so that an arrest or search concerning the former would require less evidence than one respecting the latter offense? When confronted with that question in Dunaway v. New York (1979), the Court answered in the negative, saying such a variable standard would be impracticable: "A single, familiar standard is essential to guide police officers, who have only limited time and expertise to reflect on and balance the social and individual interests involved in the specific circumstances they confront."

Another supposed variable in Dunaway was that the police action at issue was a brief detention of the suspect at the police station, not recorded as an arrest. Though the Court there found the detention "indistinguishable from a traditional arrest" and thus subject to the usual probable cause requirement, on other occasions the Supreme Court has used a balancing test : when the police action is significantly less intrusive than the usual arrest or search, there is a corresponding reduction in the required factual basis justifying that action. The leading decision is the stop and frisk case, terry v. ohio (1968), which with later decisions may be taken to mean, first, that a brief on-the-street detention of a suspect, a distinct police practice significantly less intrusive than a full-fledged arrest, is lawful upon a reasonable suspicion of criminality falling short of that needed to arrest; and second, that a frisk of that suspect for purposes of self-protection, a distinct police practice significantly less intrusive than a complete search of the person, is lawful upon a reasonable suspicion that the suspect is armed falling short of the probable cause required for a full search.

Although this balancing in Terry upheld a limited seizure and search on a watered-down version of probable cause, in other situations the Supreme Court has permitted very limited routine seizures or searches even absent any case-by-case showing of suspicion. Thus camara v. municipal court (1967) allowed a safety inspection of a dwelling, without any showing of the likelihood of code violations in that particular dwelling, where the inspection followed "reasonable legislative or administrative standards," such as those authorizing periodic inspection. And in Delaware v. Prouse (1979) the Court indicated its approval of stopping a vehicle for a driver's license and vehicle registration check, even absent suspicion that the driver was unlicensed or the car unregistered, as part of a roadblock conducted under standardized procedures.

Still another line of cases requires no factual basis for a particular seizure or search provided it is conducted in connection with some other search or seizure for which there is a sufficient basis. Where such relationships exist, the law would be very complex and difficult to apply if multiple factual bases were required, and thus sophistication has been rejected in favor of certain "bright lines" clearly marking the boundaries of permissible police conduct. Illustrative is united states v. robinson (1973), holding that a search of a person is permissible whenever that individual has just been subjected to a lawful custodial arrest. Though the Court in Robinson understood that search of the arrestee's person serves only to ensure that he does not have a weapon by which to make an escape or evidence of the crime which he might try to destroy or dispose of, it was not thought realistic to require separate police determinations whether there were grounds for arrest and whether the arrestee might be armed or in possession of evidence. Rather, the right to search was "piggybacked" onto the authority to arrest. By like reasoning, the Court held in New York v. Belton (1981) that the search of an automobile's passenger compartment can be piggybacked onto the contemporaneous arrest of an occupant, and in michigan v. summers (1981) that the brief detention of an occupant of a house can be piggybacked onto the contemporaneous execution of a search warrant for contraband there.

The Supreme Court has often expressed a preference for searches and seizures made pursuant to a warrant, reasoning that the warrant process protects Fourth Amendment rights by ensuring that critical decisions are made by "a neutral and detached magistrate." Thus the warrant-issuing authority may not be given to a prosecutor (coolidge v. new hampshire, 1971), or to a justice of the peace who receives a fee for warrants issued (Connally v. Georgia, 1977), but at least as to minor offenses may be granted to a clerk of the court acting under the supervision of a judge (Shadwick v. City of Tampa, 1972). The magistrate's responsibility is to make the critical probable cause decision which otherwise would be left to the police, and to ensure, as the Fourth Amendment requires, that the warrant describes the place to be searched and the person or things to be seized with such specificity that an officer can, as the Court put it in Steele v. United States (1925), "with reasonable effort ascertain and identify" the place, person, or thing intended.

Despite this preference for warrants, in many circumstances a search or seizure may constitutionally be made without a warrant. For one thing, no warrant need be obtained when exigent circumstances make a detour to a magistrate impracticable. Illustrative is the seminal automobile search case of carroll v. united states (1925), where it was stressed that "it is not practicable to secure a warrant because the vehicle can be quickly moved out of the locality or jurisdiction in which the warrant must be sought." However, the Court has not always dealt with the exigent circumstances issue in a consistent fashion. In chambers v. maroney (1970) the Court extended the Carroll rule to a vehicle that was in police custody and inaccessible to anyone else. On the other hand, in Vale v. Louisiana (1970) the Court chastised the police for not having obtained a search warrant a day earlier, though the probable cause needed for its issuance had unexpectedly come to the attention of the officer for the first time just minutes before the warrantless search of the arrestee's dwelling.

These different attitudes suggest that considerations other than "exigent circumstances" are at play. For example, the Court is less willing to recognize exceptions to the warrant requirement for dwelling searches than for vehicle searches. Apparently perceiving that its expanded vehicle search rule could not be explained in terms of exigent circumstances, the Court in United States v. Chadwick (1977) offered another explanation: vehicles have a "diminished expectation of privacy" which makes them unworthy of the usual Fourth Amendment warrant requirement. Yet in Arkansas v. Sanders (1979) the Court found no such diminished expectation in a suitcase, even when placed in a vehicle. It is not immediately apparent why placing one's personal items in the trunk of a car manifests less of a privacy expectation than placing those same items in some other type of container. Perhaps that is why the Court responded in United States v. Ross (1982) with this curious rule for the container-in-a-car cases: the Chambers no-warrant rule applies if there is probable cause to search the entire vehicle, but the Sanders warrant rule applies if there is probable cause to search only the container in the vehicle.

Some decisions reflect the Court's belief that certain police intrusions are more serious than others and that the warrant process is necessary only for the more serious ones. Intrusions upon a possessory interest are generally viewed as less serious than intrusions into a privacy interest; the former alone do not require warrants. Coolidge v. New Hampshire teaches that if the police are lawfully present in a place executing a search warrant and find items they believe are subject to seizure but which are not named in the warrant, they usually may make a warrantless seizure of them and need not return to the magistrate for another warrant. By contrast, when the police come into lawful possession of a closed container, for example, one which was turned over to them because misdelivered, as in Walter v. United States (1980), further intrusion into the privacy of the container ordinarily requires a warrant.

Similar analysis partly explains the rule of United States v. Watson (1976) that an arrest in a public place may be made without a warrant even if there was ample opportunity to obtain one. The Court did not consider such a siezure as great a threat to Fourth Amendment values as, say, the search of a dwelling. Thus the situation changes if the arrest can be made only by entering private premises; the Court held in payton v. new york (1980) that a warrant is then required absent true exigent circumstances. The situation also changes if the seizure of the person becomes more intrusive. As the Court explained in Gerstein v. Pugh (1975), no warrant is needed merely for "a brief period of detention to take the administrative steps incident to arrest," but if the arrestee is not promptly released then "the Fourth Amendment requires a judicial determination of probable cause as a prerequisite to extended restraint on liberty following arrest."

Yet another theme runs through the Court's decisions: no warrant is necessary when there is little for the magistrate to decide. The most obvious illustration is the rule that no search warrant is required for an inventory of an impounded vehicle because there are no special facts for the magistrate to evaluate. The point is also illustrated by comparing Payton with steagald v. united states (1981). Together the two cases stand for the proposition that an arrest warrant alone justifies entry into the intended arrestee's home to arrest him but not entry into a third party's home, which usually requires a search warrant. In the former situation, unlike the latter, there is no substantial need for a magistrate to determine on a case-by-case basis whether the suspect will probably be found in his own home. Sometimes, as in Camara v. Municipal Court, requiring warrants for housing inspections but permitting their issuance without a case-by-case probable cause showing, the Court has been sharply divided on the question of whether resort to the warrant process would be meaningful.

Still another consideration in the warrant cases of the Court is the need for "bright lines," the notion that case-by-case assessments simply are not feasible as to certain matters, so that a general rule applicable to all cases of a certain type is necessary. An example is United States v. Watson, holding that no warrant is required to arrest in a public place; a contrary holding, the Court said, would "encumber criminal prosecutions with endless litigation with respect to the existence of exigent circumstances, whether it was practicable to get a warrant, whether the suspect was about to flee, and the like." But in chimel v. california (1969) the Court overruled cases permitting a warrantless search of premises contemporaneous with a lawful arrest therein, rejecting the dissenters' claim that the earlier "bright line" rule was necessary because there often is "a strong possibility that confederates of the arrested man will in the meanwhile remove the items for which the police have probable cause to search."

The probable cause and warrant requirements of the Fourth Amendment limit the government only. They have no application to private illegal searches and seizures, as where a private person breaks into premises, seizes evidence of crime found therein, and turns that evidence over to the authorities. But if a government official should instigate or participate in such an activity, that involvement would make the private person an agent of the government. Though most Fourth Amendment cases involve the actions of police officers, the amendment unquestionably applies to other government officials as well.

The limitations of the Fourth Amendment extend only to "searches" and "seizures." The term "seizure" is considerably broader than "arrest"; thus the fact that a particular detention is not called an arrest or is less intrusive than an arrest does not mean the amendment is inapplicable. As the Court put it in Terry v. Ohio, "whenever a police officer accosts an individual and restrains his freedom to walk away, he has "seized' that person." That formulation leaves unresolved an issue of perspective: is the question whether the officer intended to restrain, or whether the suspect believed he was restrained? Either of these subjective states of mind would be difficult to prove apart from the self-serving statements of the officer and suspect, respectively, and thus an objective test is preferable. The courts, including the Supreme Court, have given insufficient attention to this matter. In Florida v. Royer (1983) a majority of the Court expressed the view "that a person has been "seized' within the meaning of the Fourth Amendment only if, in view of all of the circumstances surrounding the incident, a reasonable person would have believed that he was not free to leave." But few people feel free to walk away during a police-citizen encounter, and thus a workable test may require consideration whether the officer added to the inherent pressures by engaging in menacing conduct significantly beyond that accepted in social intercourse. Some governmental pressure causing a person to be in a certain place at a certain time, such as the grand jury subpoena upheld in united states v. dionisio (1973), does not amount to a Fourth Amendment seizure.

More difficult is the definition of a "search" within the meaning of the Fourth Amendment. The view requiring a physical intrusion into "a constitutionally protected area" was finally abandoned in Katz v. United States (1967), which involved electronic eavesdropping upon one end of a telephone conversation with a device attached to the outside of a public telephone booth. The Court held that this conduct was a search because the government "violated the privacy upon which [Katz] justifiably relied while using the telephone booth." Justice john marshall harlan, concurring in Katz in an opinion often relied upon by lower courts, enunciated "a twofold requirement, first that a person have exhibited an actual (subjective) expectation of privacy and, second, that the expectation be one that society is prepared to recognize as "reasonable."

The first of these two requirements clearly deserves no place in a theory of what the Fourth Amendment protects. Were it otherwise, as Anthony Amsterdam aptly put it, "the government could diminish each person's subjective expectation of privacy merely by announcing half-hourly on television … that we were all forthwith being placed under comprehensive electronic surveillance." Justice Harlan later came around to this position, counseling in his dissenting opinion in united states v. white (1971) that analysis under Katz must "transcend the search for subjective ecpectations," because our ecpectations "are in large part reflections of laws that translate into rules that customs and values of the past and present." A majority of the Court continues to use the "actual (subjective) expectation of privacy" formulatin, but cautioned in Smith v. Maryland (1979) that in some situations it "would provide an inadequate index of Fourth Amendment protection."

The Court has sometimes referred to the second Katz requirement simply as the "reasonable "expectation of privacy" test. From this, it might be assumed that investigative activity constitutes a search whenever it uncovers incriminating actions or objects which the law's hypothetical reasonable man would have expected to remain private, that is, those which as a matter of statistical probability were not likely to be discovered. But such an approach is unsound. Rather, as Justice Harlan later explained in his United States v. White dissent, the question here must "be answered by assessing the nature of a particular practice and the likely extent of its impact on the individual's sense of security balanced against the utility of the conduct as a technique of law enforcement." In Amsterdam's words, at the heart of the matter is "a value judgment": "whether, if the particular form of surveillance practiced by the police is permitted to go unregulated by constitutional restraints, the amount of privacy and freedom remaining to citizens would be diminished to a compass inconsistent with the aims of a free and open society."

Although Katz, so viewed, offers a useful approach to the question of what the Fourth Amendment protects, the Court's application of the test has been neither consistent nor cautious, as can be seen by comparing marshall v. barlow ' sinc. (1978) with Smith v. Maryland (1979). In Marshall, holding unconstitutional the warrantless inspection of business premises, the Court expressly rejected the government's claim that a businessman lacked any privacy expectation vis-à-vis the government when there was no such expectation as to others (in this instance, his employees). Rather, the Court reached the sensible conclusion that an unconsented entry would be a Fourth Amendment search even though the area entered was regularly used by the company's employees. But a year later, in Smith, rejecting the claim that there was a "legitimate expectation of privacy" in the numbers one dials on his telephone, the Court, though asserting that "our lodestar is Katz," concluded there was no such privacy expectation vis-à-vis the government because the telephone company's switching equipment had the capacity to record that information for certain limited business purposes. This unfortunate all-or-nothing view of privacy, as Justice thurgood marshall noted in dissent, means that "unless a person is prepared to forego use of what for many has become a personal or professional necessity, he cannot help but accept the risk of surveillance."

In still another situation the Fourth Amendment's probable cause and warrant requirements are not applicable. This situation is most commonly called a consent search, although when the facilitating party is active rather than passive it may be characterized as involving no search at all. At one time the consent doctrine was assumed to be grounded on the concept of waiver, but in schneckloth v. bustamonte (1973) the Court, saying such an approach "would be thoroughly inconsistent with our decisions," held that the underlying issue was whether the person's consent was "voluntary." One reason the concept of waiver is inappropriate here is because it has long been recognized that sometimes one party may give a consent that will be effective against another. As the Court put it in United States v. Matlock (1974), where two or more persons have joint access to or control of premises "it is reasonable to recognize that any of the coinhabitants has the right to permit the inspection in his own right and that the others have assumed the risk that one of their number might permit the common area to be searched." The Court in Matlock found it unnecessary to pass upon the correctness of a position taken by several lower courts, namely, that the Fourth Amendment's reasonableness requirement is met if the police reasonably but mistakenly conclude that the consenting person has such authority.

The Fourth Amendment was a largely unexplored territory until boyd v. united states (1886), where the Supreme Court, weaving together the Fourth and Fifth Amendments, concluded that "the seizure of a man's private books and papers to be used in evidence against him" was not "substantially different from compelling him to be a witness against himself" and thus held that physical evidence the defendant was required to produce was inadmissible. Boyd was later confined by Adams v. New York (1904) to the situation in which a positive act was required of the defendant, but in weeks v. united states (1914) the Court ruled that the "effect of the 4th Amendment" is to forbid federal courts to admit into evidence the fruits of Fourth Amendment violations. The same could not be said of the state courts, the Supreme Court decided in wolf v. colorado (1949); whether exclusion of evidence was the best way to enforce the Fourth Amendment was "an issue as to which men with complete devotion to the protection of the right of privacy might give different answers." Wolf was overruled in mapp v. ohio (1961), where the majority concluded that other remedies for Fourth Amendment violations had proven worthless. Without an exclusionary rule operative at both the state and the federal level, the Constitution's assurance against unreasonable searches and seizures "would be "a form of words,' valueless and undeserving of mention in a perpetual charter of inestimable human liberties."

Over the years the Court has given various explanations of the rationale for this exclusionary rule. In elkins v. united states (1960) the Court emphasized "the imperative of judicial integrity"—that the courts not become "accomplices in the willful disobedience of a Constitution they are sworn to uphold." A second purpose, articulated by Justice william j. brennan, dissenting in united states v. calandra (1974), is that "of assuring the people—all potential victims of unlawful government conduct—that the government would not profit from its lawless behavior, thus minimizing the risk of seriously undermining popular trust in government." This second purpose is reflected in opinions as early as Weeks. Yet a third purpose, not explicitly mentioned in the earlier cases, is that of deterring unreasonable searches and seizures. Thus, in Elkins the Court emphasized: "The rule is calculated to prevent, not to repair. Its purpose is to deter—to compel respect for the constitutional guaranty in the only effectively available way—by removing the incentive to disregard it." In recent years the Court has relied almost exclusively upon this deterrence rationale.

Over the years the deterrence issue has occasioned intense debate; some claim the exclusionary rule does not deter and should be abandoned, and others claim that it does and should be retained. Hard evidence supporting either claim is unavailable, but some argue that a deterrent effect may be assumed because of such post-exclusionary-rule phenomena as the dramatic increase in the use of warrants and stepped-up efforts to educate the police on the law of search and seizure. The debate has recently centered on a proposed "good faith" exception to the Fourth Amendment exclusionary rule, allowing admission of illegally obtained evidence if the searching or seizing officer acted in a reasonable belief that his conduct was constitutionally permissible. A limited version of the exception was adopted by the Court in united states v. leon (1984), where the exclusionary rule was "modified so as not to bar the use in the prosecution's case-in-chief of evidence obtained by officers acting in reasonable reliance on a search warrant issued by a detached and neutral magistrate but ultimately found to be unsupported by probable cause." The majority reasoned that exclusion for purposes of deterrence was unnecessary in such circumstances, as exclusion would have no significant deterrent effect on the magistrate who issued the warrant, and there is no need to deter the policeman who justifiably relied upon the prior judgment of the magistrate. Whether Leon will be a stepping-stone to adoption of a broader (and, it would seem, less justifiable and more difficult to apply) "good faith" exception, applicable also in without-warrant cases, remains to be seen.

The current dimensions of the Fourth Amendment exclusionary rule are mostly tailored to the deterrence rationale. The rule is not used in certain settings on the assumption that the incremental gain in deterrence is not worth the cost. Illustrative are United States v. Calandra, refusing to compel exclusion at the behest of a grand jury witness because it "would achieve a speculative and undoubtedly minimal advance in the deterrence of police misconduct at the expense of substantially impending the role of the grand jury"; and United States v. Janis (1976), declining to require exclusion in federal tax litigation of evidence uncovered in a state criminal investigation of gambling because "common sense dictates that the deterrent effect of the exclusion of relevant evidence is highly attenuated when the "punishment' imposed upon the offending criminal enforcement officer is the removal of that evidence from a civil suit by or against a different sovereign." Even in the context of a criminal trial the deterrent objective of the exclusionary rule is sometimes perceived as outweighed by competing considerations. This explains the rule in Walder v. United States (1954) that the government may use illegally obtained evidence to impeach the defendant's testimony, so that the defendant cannot "turn the illegal method by which evidence in the Government's possession was obtained to his own advantage, and provide himself with a shield against contradiction of his untruths."

Who may invoke the exclusionary rule? The rule of standing generally is that a constitutional challenge may be raised only by those who have an interest in the outcome of the controversy, and who are objecting to a violation of their own rights. A defendant in a criminal case against whom illegally obtained evidence is being offered certainly meets the first requirement, but he does not necessarily meet the second. As to the latter, the fundamental question is whether the challenged conduct intruded upon his freedom or expectation of privacy or only that of someone else, as Rakas v. Illinois (1978) illustrates. The Court held that passengers in a car did not have standing to object to a search under the seats and in the glove compartment of that vehicle. Essential to the holding were the conclusions that these passengers were not claiming that the car had been illegally stopped, that they "asserted neither a property nor a possessory interest in the automobile, nor an interest in the property seized," and that the areas searched were ones "in which a passenger qua passenger simply would not have a legitimate expectation of privacy." The Supreme Court refused in alderman v. united states (1969) to adopt a rule of "target standing" allowing a defendant to object to any Fourth Amendment violation committed for the purpose of acquiring evidence for use against him. This refusal limits to some extent the deterrent effect of the exclusionary rule, for police sometimes deliberately direct an illegal search at one person because they are seeking evidence to use against another person they know will not be able to question their conduct.

What evidence is subject to challenge under the exclusionary rule? Under the fruit of the poisonous tree doctrine, the exclusionary rule applies not only to the immediate and direct fruits of a Fourth Amendment violation (the physical evidence found in a search), but also to secondary or derivative evidence (a confession acquired by confronting a person with that physical evidence). Of course, in a criminal investigation the discovery of one fact often plays some part in the discovery of many others, and they in turn contribute to the uncovering of still others, and so on, but the fruits doctrine is not pushed this far. Even the fact first discovered by an illegal act does not become forever "inaccessible" for court use: it may still be proved "if knowledge of [the fact] is [also] gained from an independent source," as in silverthorne lumber co. v. united states (1920). The "inevitable discovery" doctrine accepted in Nix v. Williams (1984), whereunder illegally obtained evidence is admissible if "the prosecution can establish by a preponderance of the evidence that the information ultimately or inevitably would have been discovered by lawful means," likewise serves to put the police in no worse position than they would have been if their misconduct had not occurred. Another limitation is provided by the test in Wong Sun v. United States : "whether, granting establishment of the primary illegality, the evidence to which instant objection is made has been come at by exploitation of that illegality or instead by means sufficiently distinguishable to be purged of the primary taint." In that case the taint of one defendant's illegal arrest was deemed dissipated by his release on his own recognizance, so that the taint did not reach a subsequently given confession. Considerations close to the deterrent function of the exclusionary rule also come into play here. Thus, suppression of derivative evidence is much more likely if it appears that the primary illegality was a clearly unconstitutional act or that it was undertaken for the purpose of acquiring that derivative evidence. For example, a confession will be deemed the fruit of an obviously illegal arrest made in the hope of acquiring a confession.

It cannot be denied that there is ample room for reasonable disagreement regarding the rationales and results of a number of the Supreme Court's Fourth Amendment decisions. In the main, however, the Court's response to the four fundamental questions just discussed has been indisputably appropriate and sound. The decisions on the requisite factual basis for a seizure or search have generally struck a fair balance between privacy and law enforcement interests. The Court's rulings regarding the warrant requirement have prevented the warrant process from becoming so overburdened as to become a mechanical and meaningless routine, yet have provided added protection to those Fourth Amendment interests that are valued most. The decisions defining the activities to which the amendment applies—especially Katz and its justified expectation of privacy test—provide an approach that should enable the Court to protect against new threats to the individual's right to be free of intrusive government surveillance. Finally, it is the Court's insistence upon an exclusionary rule as an enforcement mechanism that has kept the Fourth Amendment from being reduced to "a form of words."

Wayne R. LaFave
(1986)

Bibliography

Amsterdam, Anthony G. 1974 Perspectives on the Fourth Amendment. Minnesota Law Review 58:349–477.

Grano, Joseph D. 1978 Perplexing Questions about Three Basic Fourth Amendment Issues: Fourth Amendment Activity, Probable Cause, and the Warrant Requirement. Journal of Criminal Law and Criminology 69:425–463.

Kamisar, Yale 1983 Does (Did) (Should) the Exclusionary Rule Rest on a "Principled Basis" Rather Than an "Empirical Proposition"? Creighton Law Review 16:565–667.

La Fave, Wayne R. 1978 Search and Seizure: A Treatise on the Fourth Amendment, 3 vols. St. Paul, Minn.: West Publishing Co.

Landynski, Jacob W. 1966 Search and Seizure and the Supreme Court. Baltimore, Md.: Johns Hopkins University Press.

Oaks, Dallin H. 1970 Studying the Exclusionary Rule. University of Chicago Law Review 37:665–757.

United States, Congress, Senate Committee on the Judiciary, Subcommittee on Criminal Law 1982 The Exclusionary Rule Bills, 97th Cong., 1st & 2d sess.