Defendant appeals from a judgment on his conviction of public indecency after trial to the court. ORS 163.465(lXc).1 He assigns as error the trial court’s denial of his motion to suppress evidence obtained from a warrantless police surveillance of a public restroom.
Approximately two years prior to defendant’s arrest, the police began clandestine surveillance of a men’s public restroom at a rest area along an interstate highway. A screened vent was cut in a wall common to the men’s restroom and an adjacent storage room. From this vantage point, an officer, standing on a ladder in the storage room, could view the toilet stalls below. Defendant’s arresting officer testified that he had made over 130 arrests at this restroom in less than three months of surveillance. No application for a search warrant was ever made.
The restroom itself contained two doorless toilet stalls separated by a partition. A person standing in front of either stall would be able to see the occupant. The partition between the two stalls was perforated by two holes approximately 1/2 inch in diameter which were apparently caused by moving the location of the tissue dispenser.
Looking through the storage room vent, the arresting officer observed defendant enter the restroom, walk past the urinals, and bend over to look under the toilet stalls. At that time, both stalls were occupied — one by an unidentified male and the other by an undercover police officer participating in the surveillance. Finding both stalls occupied, defendant *828left the restroom area. After the other two men departed, defendant reentered and sat on a toilet. Observing defendant reenter the restroom, Officer Gable left the storage area and also entered the restroom. He walked by the stall occupied by defendant and sat down on a toilet in the adjacent stall. Looking through a hole in the partition, the officer observed the defendant sitting on the toilet masturbating. Because of what he observed, the officer walked to the front of defendant’s stall. There he observed him standing masturbating while facing the open end of the stall. Defendant was arrested and charged with public indecency.
There were three stages of police surveillance. The first was from the storage room vent; the second was through the holes in the partition of the adjacent toilet stall; and the third was from the area in front of defendant’s stall. The threshold question is whether these police observations constitute searches within the confines of the Fourth Amendment. Since Katz v. United States, 389 US 347, 88 S Ct 507, 19 L Ed 2d 576 (1967), it has become clear that they do.
In Katz, the defendant was convicted of transmitting wagering information by telephone in violation of federal law. At trial, the defendant contended unsuccessfully that evidence obtained by means of an electronic listenening device attached to the outside of the telephone booth was a search which violated his Fourth Amendment rights. The United States Supreme Court noted that
"* * * 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. [Citations omitted.] But what he seeks to preserve as private, even in an area accessible to the public, may be constitutionally protected. [Citations omitted.]
"The government stresses the fact that the telephone booth from which the petitioner made his calls was constructed partially of glass so that he was as visible after he entered it as he would have been if he had remained outside. But what he sought to exclude when he entered the booth was not the intruding eye *829— it was the uninvited ear. He did not shed his right to do so simply because he made his calls from a place where he might be seen. ** * *
******
"* * * The Government’s activities in electronically listening to and recording the petitioner’s words violated the privacy upon which he justifiably relied while using the telephone booth and thus constituted a 'search and seizure’ within the meaning of the Fourth Amendment. * * *” 389 US at 351-53.
In a frequently quoted passage from his concurring opinion in Katz, Justice Harlan noted that the protection of the Fourth Amendment against unreasonable searches and seizures involves two elements:
"* * * [F]irst, 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.’ * * *” 389 US at 361.
An individual’s "reasonable expectation of privacy” is therefore the Fourth Amendment touchstone for determining one’s right to be free from unreasonable governmental intrusions.
In applying the reasoning of Katz, cases similar on their facts to the one before us have concluded that warrantless clandestine surveillance of a restroom constitutes a search in violation of the protection afforded by the Fourth Amendment. See, e.g., Kroehler v. Scott, 391 F Supp 1114 (E.D. Pa. 1975); People v. Triggs, 8 Cal 3d 884, 106 Cal Rptr 408, 506 P2d 232 (1973); Bielicki v. Superior Court, 57 Cal 2d 602, 21 Cal Rptr 552, 371 P2d 288 (1962); State v. Bryant, 287 Minn 205, 177 NW 2d 800 (1970).2
*830The state would have us view the absence of a door on the toilet stall as foreclosing an individual’s reasonable expectation of privacy from clandestine surveillance. Buchanan v. State, 471 SW 2d 401 (Tex Crim 1971), so held, but we do not find it persuasive. While the occupant of a doorless toilet stall in a public restroom cannot reasonably expect privacy from the gaze of a person standing in front of his stall, he would not expect a hidden agent of the state to be spying on him from some concealed vantage point. Such occupant is entitled to hold a subjective expectancy of privacy to the limited extent that the design of the facility affords him. Brown v. State, 3 Md App 90, 238 A2d 147 (1968).
The second point in Justice Harlan’s test as to what searches are subject to Fourth Amendment protection is that the expectation of privacy be one "that society is prepared to recognize as reasonable.”
As aptly framed by Professor LaFave in his treatise on the Fourth Amendment:
"* * * Thg issue is not whether the resort to that practice in the particular case at hand, given either the grounds which the police had in advance for engaging in the practice or the hindsight knowledge that the practice was directed toward a person engaged in criminal activity, is particularly offensive. Rather, the matter must be viewed from a much broader perspective. It must be asked whether permitting the police regularly to engage in that type of practice, limited by nothing 'more than self restraint by law enforcement officials’ requires the 'people’ to which the Fourth Amendment refers to give 'up too much freedom as the cost of privacy. ’ That is, the fundamental inquiry is whether that practice, if not subjected to Fourth Amendment restraints, would be intolerable because it would either encroach too much *831upon the 'sense of security’ or impose unreasonable burdens upon those who wished to maintain that security.” W. LaFave, Search and Seizure, § 2.1 (1978). (Emphasis supplied.)
In balancing the legitimate need to enforce the law and the difficulty encountered by law enforcement officials in doing so against what we believe society regards as reasonable, we cannot ignore that the method used here was not selective and affected persons using the facilities for proper purposes as well as those who used them as defendant did.
We believe that while defendant could not entertain any expectation of privacy from observation from the front of the open toilet stall, he could reasonably expect, and society would recognize that expectation as reasonable, that he would not be subjected to surveillance of his use of the toilet facilities properly, or otherwise, from a hidden vantage point. Because that expectation is both subjectively and objectively reasonable, it is entitled to the protection of the Fourth Amendment.
We are persuaded that the reasoning in People v. Triggs, supra, represents the proper application of the Fourth Amendment to the facts of this case. In Triggs, as in the present case, the state contended that, because the toilet stall had no door, defendant had no reasonable expectation of privacy and that therefore the police officer’s observation of defendant from a hidden place did not constitute a "search.” Defendant’s motion to suppress the officer’s testimony as "the intangible fruit of an illegal search” was denied. On appeal from the resulting conviction, the Supreme Court of California reversed. It noted that in Britt v. Superior Court, 58 Cal 2d 469, 24 Cal Rptr 849, 374 P2d 817 (1962), and Bielicki v. Superior Court, supra, it had previously rejected arguments that clandestine observations of public toilet stalls were not searches where the places from which the observations were made were created for purposes other than surveillance or where the stall was open to observation from areas accessible to the public.
*832The court stated:
"* * * [T]he People here urge us to hold that clandestine observation of doorless stalls in a public restroom is not a 'search’, and hence is not subject to the Fourth Amendment’s prohibitions of unreasonable searches. This would permit the police to make a routine practice to observe from hidden vantage points the restroom conduct of the public whenever such activities do not occur within fully enclosed toilet stalls and would permit spying on the "innocent and guilty alike.” Most persons using public restrooms have no reason to suspect that a hidden agent of the state will observe them. The expectation of privacy a person has when he enters a restroom is reasonable and is not diminished or destroyed because the toilet stall being used lacks a door.
"* * * In seeking to honor reasonable expectations of privacy through our application of search and seizure law, we must consider the expectations of the innocent as well as the guilty. When innocent people are subjected to illegal searches — including when, as here, they do not even know their private parts and bodily functions are being exposed to the gaze of the law — their rights are violated even though such searches turn up no evidence of guilt. Save through the deterrent effect of the exclusionary rule, there is little court’s can do to protect the constitutional right of persons innocent of any crime to be free from unreasonable searches.” 506 P2d at 236-38.
Concluding that the activities of the police in Triggs constituted a search within the purview of the Fourth Amendment, the California Supreme Court held that because the evidence obtained in the warrantless search was not based on probable cause, it should have been suppressed.
Applying this analysis to the case before us, as to the first stage of surveillance, the officer’s observation of defendant from the storage room vent was clearly a search. That search is not really at issue here because it revealed no incriminating evidence.3
*833The second stage of surveillance, however, consisting of the officer peering through a hole in the partition of the adjacent toilet stall, was similarly a search within the purview of the Fourth Amendment. The officer’s view of defendant’s activities constituted a search and resulted in a seizure of incriminating evidence.
Having concluded that this second stage of the observation was a search and seizure, we must determine its legality. Subject only to a few well-guarded exceptions, warrantless searches and seizures are per se unreasonable, State v. Florance, 270 Or 169, 177, 527 P2d 1202 (1974), and the burden of proving the reasonableness of the search is on the state, ORS 133.693(4).
In order to justify a warrantless search, the state must prove that there was probable cause to believe that the search would disclose incriminating evidence and that exigent circumstances were present which outweighed the need for an independent judicial determination of probable cause. State v. Basler, 24 Or App 723, 727, 546 P2d 1084 (1976). Prior to the second observation, the officer had no cause to suspect defendant of criminal conduct. Defendant’s behavior was susceptible to an innocent explanation. Thus, the officer did not have probable cause to justify a search. Rather, this was a general nonselective exploratory search affecting both the innocent and the guilty alike which cannot withstand constitutional attack. As the Supreme Court stated in Katz, 389 US at 357-59.
"* * *[T]he Constitution requires 'that the deliberate, impartial judgment of a judicial officer ... be interposed between the citizen and the police’ * * *.
******
"And bypassing a neutral predetermination of the scope of a search leaves individuals secure from *834Fourth Amendment violations 'only in the discretion of the police.’ * * *
"* * * Wherever a man may be, he is entitled to know that he will remain free from unreasonable searches and seizures. * * *”
The third stage of surveillance was from the area in front of the doorless stall. Even though this occurred in a place where the police had a right to be, we cannot ignore officer Gable’s testimony at the suppression hearing that he was there at the critical time only because of what he observed through the hole in the partition.4 Consequently, the evidence obtained was the product of the initial illegal search.5 Wong Sun v. United States, 371 US 471, 83 S Ct 407, 9 L Ed 2d 441 (1963).
*835Because the evidence that led to defendant’s conviction was illegally seized, the judgment must be reversed.6
Reversed and remanded for a new trial.
ORS 163.465(l)(c):
"(1) A person commits the crime of public indecency if while in, or in view of, a public place he performs:
* ** * *
"(c) An act of exposing his genitals with the intent of arousing the sexual desire of himself or another person.”
In his discussion of clandestine surveillance of public restrooms, Professor LaFave states in his treatise on the Fourth Amendment:
"* * * At least since the Katz decision, it is clear beyond question that such surveillance into a closed rest room stall constitutes a Fourth Amendment search.
* * * #
"Katz, properly viewed, extends the limitations of the Fourth Amendment to those forms of police surveillance which cannot be *830'permitted to go unregulated by constitutional restraints.’ Clandestine peeping into rest rooms is surely one type of surveillance which cannot be left to the whim of the police, whether there are doors on the stalls or not, and thus [ People v.] Triggs rather than Buchanan [v. State] represents the better view. * * *” W. LaFave, Search and Seizure, § 2.4 (c)(1978).
The state did not contend, in the event that we determine the first stage of surveillance to be a Fourth Amendment search, that there was *833probable cause and exigent circumstances present to justify a general, clandestine search without a warrant of all occupants of the toilet stalls in this particular restroom on the date in question. It is difficult to imagine any exigency in view of the fact that such surveillance had been going on for approximately two years.
We note that under circumstances where the evidence is not tainted by a prior illegality, an observation by an officer in front of a doorless toilet stall would not be a Fourth Amendment search under our analysis of the "reasonable expectation of privacy” test set forth in Katz. Moreover, such an observation could be found not to constitute a search under a (non - Coolidge ) plain view analysis. See W. LaFave, Search and Seizure: Plain View, Smell and Hearing; Aiding the Senses, § 2.2(a) (1978) (distinguishing the situation in which a search has occurred and the plain view doctrine of Coolidge v. New Hampshire, 403 US 443, 91 S Ct 2022, 29 L Ed 2d 564 (1971), is applied to justify the subsequent warrantless seizure of evidence from the situation in which there has been no search because the vantage point from which the "plain view” observation was made was not within a constitutionally protected area).
Although not briefed or argued by the State on appeal, we have considered the "inevitable discovery” exception to the "fruit-of-the-poisonous-tree” doctrine and find it inapplicable to this case. In Wong Sun v. United States, 9 L Ed 2d at 455, the Supreme Court said that the "fruit of the poisonous tree” doctrine
"* * * has no application because the Government learned of the evidence 'from an independent source,’ * * * [or] the connection between the lawless conduct of the police and the discovery of the challenged evidence has 'become so attenuated as to dissipate the taint.’ * ** [T]he * * * question in such a case is '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.’ Marguire, Evidence of Guilt, 221 (1959). * * *”
In the present case, the challenged evidence was not obtained by means sufficiently distinguishable from the initial illegality so as to be purged of the primary taint. There was no independent source, nor any attenuation which would dissipate the taint.
*835Moreover, the doctrine of "inevitable discovery” is not applicable here where the officer testified at the suppression hearing that his presence in front of defendant’s toilet stall was because of his previous clandestine searches. Under ORS 133.683:
"If a search or seizure is carried out in such a manner that things seized in the course of the search would be subject to suppression, and if as a result of such search or seizure other evidence is discovered subsequently and offered against a defendant, such evidence shall be subject to a motion to suppress unless the prosecution establishes by a preponderance of the evidence that such evidence would have been discovered by law enforcement authorities irrespective of such search or seizure, and the court finds that exclusion of such evidence is not necessary to deter violations of ORS 133.525 to 133.703.”
The prosecution has not established by a preponderance of the evidence that irrespective of the unlawful search and seizure, this evidence would have inevitably been discovered. To do so, we would have to speculate that had the officer not peered through the hole in the partition he would nevertheless have left the toilet stall he occupied and observed defendant in his unlawful conduct. Such speculation is not permissible. State v. Paz, 31 Or App 851, 874, 572 P2d 1036 (1977).
We do not imply that clandestine surveillance of a restroom is perse an impermissible method of law enforcement, only that prior to commencement of such surveillance, a search warrant must be obtained.