The issue is whether police use of a radio transmitter to locate a private automobile to which the transmitter has been surreptitiously attached is a “search” or “seizure” under Article I, section 9, of the Oregon Constitution. 1 We hold that it is a search. Because no warrant authorized the police to locate defendant’s automobile in this manner, we affirm the decisions of the circuit court and the Court of Appeals to suppress the evidence thereby obtained.
I.
1. We base our statement of the facts on the findings of the circuit court.
2
A trial court’s findings are binding upon appellate courts if there is constitutionally sufficient evidence in the record to support those findings.
See State v. Warner,
In late 1984, police officers in Washington and Columbia Counties began to suspect that defendant was committing residential burglaries in a rural area along the border of those two counties. The police suspected defendant because he was then on probation for burglaries that were committed in a somewhat similar fashion, because he lived in the area, and because his automobile had been seen near some of the burglarized residences when those burglaries were thought to have been committed. 3 To verify their suspicion, police *160 officers attempted to follow defendant’s automobile on a number of occasions but were unsuccessful. The rural area made it difficult to follow defendant closely without detection, and defendant began to drive evasively after becoming aware of the efforts to follow him.
Having failed to follow defendant visually, members of the Washington County Sheriffs Office decided to follow him by means of a radio transmitter attached to his automobile. A detective from that office testified that radio transmitters were used to follow individuals pursuant to “in-house criteria.”
“Number one, it has to be a person that our intelligence tells [us] is active in whatever criminal activity we’re trying to investigate. Number two, another major consideration that we have is we have attempted to follow them through our ordinary means. That means to have four or five cars out and try on their regular moving surveillance to follow the person. It’s after that fails and we have no other resource then we will use the bird dogs [radio transmitters].”
The detective testified that no effort was made to obtain a search warrant to attach or monitor the transmitter because no warrant was believed to be required so long as the attachment was to the outside of the automobile while it was in a public place.
On January 15,1985, a Washington County Sheriffs Office detective surreptitiously attached a small, battery-powered radio transmitter to the underside of defendant’s automobile while it was parked in a public parking lot. Magnets in the transmitter held it to the automobile, and the attachment was made without entering the vehicle. The transmitter broadcasted a radio signal by which a companion receiver placed in an automobile or aircraft could determine the direction of the transmitter from the receiver. By gauging the strength of the signal received, a rough estimate of the transmitter’s distance could also be made.
Initial efforts to follow defendant’s automobile with a *161 ground-based receiver were either unsuccessful or did not uncover any criminal activity. On January 21, 1985, a police officer replaced the transmitter’s batteries, again while the automobile was in a public parking lot. The next day, after failing to pick up the signal with the ground-based receiver, officers attempted to locate the automobile with a receiver in a small airplane. That receiver also failed to pick up the signal in the area in which the burglaries had been committed, but, by climbing to 4500 feet and flying in widening patterns, the officers were able to pick up a faint signal, which was tracked to a rural area near Molalla, Oregon, some 40 miles to the southeast in Clackamas County. There they discovered defendant’s automobile parked along a public road near a residence. From the airplane, they visually followed the automobile when it moved to the driveway of another residence, where they observed defendant get out of the automobile and act in a manner that suggested to them that he was burglarizing the residence.
Defendant was indicted for burglarizing the two Clackamas County residences and moved to suppress all evidence derived from the use of the radio transmitter attached to his automobile. 4 The circuit court held that use of the transmitter required a warrant based upon a showing of probable cause to believe that defendant’s automobile was engaged in ongoing criminal activity. Because the police had not obtained a warrant, and because the court concluded that no exigency obviated the need for a warrant, the court allowed defendant’s motion to suppress.
On the state’s appeal pursuant to ORS 138.060(3), a panel of the Court of Appeals affirmed with one judge dissenting.
State v. Campbell,
II.
Defendant argues that the attachment and monitoring of the transmitter violated his rights under Article I, section 9, and the Fourth Amendment to the United States Constitution.
5
Before deciding a federal claim, we must first consider and decide all questions of state law.
State v. Kennedy,
In accordance with their “in-house criteria,” the police officers attached and monitored the transmitter on defendant’s automobile in order to investigate and prevent the crime of burglary, ORS 164.225. No Oregon statute governs the use of radio transmitters to locate objects or people, and, apart from what the constitution may require, the conduct of the police officers in attaching and monitoring the transmitter was not contrary to any other law. The issue on which the lawfulness of the police conduct turns, then, is whether the attachment or monitoring of the transmitter was a search or seizure under Article I, section 9, of the Oregon Constitution.
*163
A search or seizure to obtain evidence of a crime is unconstitutional if no warrant authorized the search or seizure and there is no exigency that would obviate the need for a warrant.
State v. Kosta,
III.
This court has often stated that “privacy” is the interest protected by Article I, section 9, against unreasonable searches but has had little occasion to further define that interest.
See, e.g., State v. Tanner, supra,
Privacy is also recognized by the Supreme Court of the United States as the interest protected by the Fourth Amendment’s prohibition on unreasonable searches.
See Katz v. United States,
This court has expressed doubts about the wisdom of defining Article I, section 9, searches in terms of “reasonable expectations of privacy.”
See State v. Tanner, supra,
“While [the “expectation of privacy”] formulations represent an advance over the unsophisticated trespass analysis of the common law, they too have their limitations and can, ultimately, lead to the substitution of words for analysis. The analysis must, in my view, transcend the search for subjective expectations or legal attribution of assumptions of risk. Our expectations, and the risks we assume, are in large part reflections of laws that translate into rules the customs and values of the past and present.
“Since it is the task of the law to form and project, as well as mirror and reflect, we should not, as judges, merely recite the expectations and risks without examining the desirability of saddling them upon society. The critical question, therefore, is whether under our system of government, as reflected in the Constitution, we should impose on our citizens the risks of the electronic listener or observer without at least the protection of a warrant requirement.” (Footnote omitted.)
United States v. White,
We therefore turn to the substance of the state’s arguments, shorn of their “reasonable expectation of privacy” packaging. The state, relying on Karo and Knotts, makes essentially two arguments, which are based on somewhat different factual premises. The first argument is that no privacy interest of defendant was infringed because the transmitter disclosed only what any member of the public could legitimately have observed. The second argument is that, even if the transmitter “enhanced” the observations of the police, defendant had no privacy interest outside “protected premises.” Thus, the police engage in a search only if they monitor a transmitter while it is within “protected premises” such as a home.
We do not accept either the factual or the legal premise of the state’s first argument. The state says in its brief, quoting
United States v. Knotts, supra,
“When defendant traveled over the public streets and onto the *166 driveways of other persons’ property, he ‘voluntarily conveyed to anyone who wanted to look the fact that he was traveling over particular roads in a particular direction, the fact of whatever stops he made, and the fact of his final destination when he exited from public roads onto [someone else’s] private property.’ ” (Bracketed material added by the state.)
The argument is factually unsound on the record before us, because the police, notwithstanding diligent efforts, found it impossible to follow defendant’s automobile through visual surveillance. Indeed, their policy was not to use a transmitter unless visual surveillance had failed. Moreover, it is wrong to characterize the radio transmitter as simply a device for “enhancing” visual observations in the manner of moderate power binoculars or camera lenses.
Cf. State v. Louis, supra,
But even were we to accept the factual premise of the state’s first argument, its legal premise is also unsound. That premise is that information legitimately available through one means may be obtained through any other means without engaging in a search.
The constitutional provisions against unreasonable searches and seizures do not protect a right to keep any information, no matter how hidden or “private,” secret from the government.
Cf. State v. Weist,
The state’s second argument does not rest on the factual premise that the police observed with the transmitter what any member of the public could have observed. The argument, rather, is that only government actions that observe conduct or objects within “protected premises” are searches, for, so the state argues, it is only within “protected premises” that an individual has a privacy interest protected by Article I, section 9. In making this argument, the state concedes that the transmitter at least “enhances” what members of the public can observe.
The state cites State v. Louis, supra, in support of its argument. After holding that police use of a 135 mm camera lens to take pictures of the interior of a house from a neighboring house was not a “search” under Article I, section 9, the court continued:
“Such a case may not be made out, however, if objects or conduct in protected premises can be seen or overheard only by technologically enhanced efforts. A determined official effort to see or hear what is not plain to a less determined observer may become an official ‘search.’ ” (Emphasis added.)
“Defendant was observed in his living quarters, which are the quintessential domain protected by the constitutional guarantee against warrantless searches. Application of the guarantee to people’s ‘houses,’ Or Const, Art I, § 9, need not depend on also showing an ‘expectation of privacy.’ That phrase was employed in Katz v. United States,389 US 347 ,88 S Ct 507 ,19 L Ed 2d 576 (1967), to extend personal Fourth Amendment protections beyond the areas literally protected by that amendment (in that case to a person using a public telephone booth), not to qualify the unquestioned protection afforded to private quarters.”
For a half-century, the United States Supreme Court defined a Fourth Amendment search as a physical trespass to a “constitutionally protected area,”
i.e.,
a physical trespass to those “areas” explicitly protected by the Fourth Amendment: persons, houses, papers, and effects.
See, e.g., Olmstead v. United States, 211
US 438, 465-66,
In
Katz,
FBI agents placed a listening device on the
*169
outside of a public telephone booth. The device was not a wiretap and would ordinarily pick up only the words of the person in the booth.
Id,.,
“[T]his effort to decide whether or not a given ‘area,’ viewed in the abstract, is ‘constitutionally protected’ deflects attention from the problem presented by this case. For the Fourth Amendment protects people, not places. What a person knowingly exposes to the public, even in his own home or office, is not a subject of Fourth Amendment protection. But what he seeks to preserve as private, even in an area accessible to the public, may be constitutionally protected.” (Footnote and citations omitted.)
To be sure, the state does not ask us to go so far as to rule that there is no search without a physical trespass to “protected premises.” But the notion that the interests protected against government searches by Article I, section 9, are limited to interests in certain “protected premises” is unsustainable given this court’s repeated recognition of privacy as the principal interest protected against unlawful searches.
See State v. Tanner, supra,
With respect to the use of radio transmitters to locate objects and people, it is not even possible to ascertain whether the use is directed at a “protected premise” until after the
*170
object or person is located. Learning the location of the object or person is, after all, the purpose of the device. This fact demonstrates another difficulty with the state’s contention that police use of transmitter is a search only if the transmitter is in a “protected premise.” The constitution is addressed to the government. The rules laid down for the government by Article I, section 9, must be rules that the government is capable of following.
See State v. Tanner, supra,
A privacy interest, as that phrase is used in this court’s Article I, section 9, opinions, is an interest in freedom from particular forms of scrutiny. The interest is not one of freedom from scrutiny in general, because, if that were the case, any form of scrutiny would infringe a privacy interest and thereby be considered a search. A court has never held, for example, that a police officer engages in a search by making unaided observations from a public place, and an individual therefore cannot be said to have a constitutionally protected interest in freedom from such scrutiny.
Government scrutiny aside, individual freedom from scrutiny is determined by social and legal norms of behavior, such as trespass laws and conventions against eavesdropping.
See Katz v. United States, supra,
Our intention is not to set forth a definition of search based upon social and legal norms of behavior but to clarify the nature of the interest protected by Article I, section 9. Social and legal norms cannot govern the scope of the constitutional provision, which itself plays a substantial role in shaping those norms.
See, e.g., United States v. White, supra,
As we noted above, use of a radio transmitter to
*172
locate an object to which the transmitter is attached cannot be equated with visual tracking.
See also
1 LaFave, Search and Seizure § 2.7(d) (2d ed 1987). Any device that enables the police quickly to locate a person or object anywhere within a 40-mile radius, day or night, over a period of several days, is a significant limitation on freedom from scrutiny, as the facts of this case demonstrate. The limitation is made more substantial by the fact that the radio transmitter is much more difficult to detect than would-be observers who must rely upon the sense of sight. Without an ongoing, meticulous examination of one’s possessions, one can never be sure that one’s location is not being monitored by means of a radio transmitter. Thus, individuals must more readily assume that they are the objects of government scrutiny. Professor Amsterdam and Justice Harlan, among others, have observed that freedom may be impaired as much, if not more so, by the threat of scrutiny as by the fact of scrutiny.
See United States v. White, supra,
The problem presented by this case is essentially much like that presented in Katz, which was whether using a hidden listening device placed in a public place could be considered a search. Conversations in public may be overheard, but it is relatively easy to avoid eavesdroppers by lowering the voice or moving away. Moreover, one can be reasonably sure of whether one will be overheard. But if the state’s position in this case is correct, no movement, no location and no conversation in a “public place” would in any measure be secure from the prying of the government. There would in addition be no ready means for individuals to ascertain when they were being scrutinized and when they were not. That is nothing short of a staggering limitation upon personal freedom. We could not be faithful to the principles underlying Article I, section 9, and conclude that such forms of surveillance were not searches.
We hold that the use of the radio transmitter to locate defendant’s automobile was a search under Article I, section 9, of the Oregon Constitution. Because the police did not have a warrant to use the transmitter, and because no exigency obviated the need to obtain a warrant, use of the transmitter violated defendant’s rights under Article I, section *173 9. 9 Accordingly, the circuit court properly suppressed all evidence obtained through use of the device.
Our disposition of this case makes it unnecessary to decide whether the Court of Appeals correctly held that the attachment and monitoring of the transmitter was a “seizure” under Article I, section 9. We also need not address defendant’s Fourth Amendment arguments.
The judgment of the circuit court and the decision of the Court of Appeals are affirmed. The case is remanded to the circuit court for further proceedings. 10
Notes
Article I, section 9, of the Oregon Constitution provides:
“No law shall violate the right of the people to be secure in their persons, houses, papers, and effects, against unreasonable search, or seizure; and no warrant shall issue but upon probable cause, supported by oath, or affirmation, and particularly describing the place to be searched, and the person or thing to be seized.”
This court has for many years urged trial courts to make adequate findings of fact in pretrial orders.
See, e.g., State v. Wise,
Witnesses for the state at the suppression hearing could only generally state the reasons for suspecting defendant of committing the burglaries. For example, they testified that defendant’s automobile had been seen “near” or “in the area” of some of the burglaries, but they did not testify how near or even which burglaries. Especially given that defendant lived in the area, these details would have been important to any judicial evaluation of the substantiality of the police officers’ suspicion. In addition, the similarity between the burglaries of which defendant was convicted and the burglaries of which he was suspected was stated as “kicking in front doors to gain entrance and then taking all kinds of property.” The circuit court found that this “modus *160 operandi” was not “unusual or unique and that burglars in general often entered residences in such fashion and took such articles.” The court concluded that the facts presented did not establish probable cause to believe that defendant was engaged in burglarizing residences in the area.
Defendant did not challenge the visual observations from the airplane, except as the product of the use of the transmitter.
The Fourth Amendment provides:
“The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.”
The Fourth Amendment applies to the states through the due process clause of the Fourteenth Amendment.
Ker v. California,
Although the phrase “reasonable expectation of privacy” is often attributed to
Katz v. United States,
We note that there is no presumption that interpretations of the Fourth Amendment by the Supreme Court of the United States are correct interpretations of Article I, section 9.
See State v. Kennedy,
Cf. United States v. White, supra,
In
United States v. Karo,
We note that defendant was on probation for burglary when the transmitter was used. Among the conditions of his probation was that he be subject to certain searches not involved in this case. Use of a locating transmitter to keep track of a probationer’s movements may be constitutionally permissible without further justification if made a condition of probation. We express no opinion on that issue or on whether such a condition would be statutorily permissible under ORS 137.540. Our decision today also does not address the constitutionality of devices that have recently come into use for monitoring the location of persons sentenced to “house arrest.”
