Opinion
BROUSSARD, J.
Defendant Kenneth Lee Donaldson, charged with murder involving special circumstances, robbery, and burglary, seeks a writ of mandate to compel respondent superior court to grant his motion to suppress evidence. He asserts that the use of a hidden microphone to record a conversation between him and his brother Lester while they were waiting in a police interview room constitutes an unlawful search under both federal and California law.
We explain that under settled federal precedent and under the California decisions prior to De Lancie v. Superior Court (1982) 31 Cal.3d 865 [183 Cal.Rptr. 866, 647 P.2d 142], the secret monitoring and recording of unprivileged conversations in prisons, jails, and police stations did not constitute an unlawful search. De Lancie held that such monitoring was unlawful unless done to protect institutional security. Because the purpose of De Lancie would not be furthered by applying its holding retroactively, we conclude that De Lancie does not govern police conduct that took place before that decision was filed. We therefore deny defendant’s petition for writ of mandate.
1. Summary of facts and proceedings below.
On the morning of September 15, 1980, someone broke into the Wise Owl Pre School and killed Mattie Chissell, one of the teachers. About three weeks later, on October 6, Lester Donaldson, defendant’s brother, was present at the southeast police station as a potential witness, not a suspect, and was not under arrest.
Later that same day defendant telephoned the station and then went voluntarily to the police station where he, too, was considered a potential witness.1 A police officer brought defendant to interview room 109 where Lester was seated, and told defendant, “Have a seat and we will be with you in a minute,” or words to that effect. Lester and defendant were then left alone in the room with the door closed.
[28]*28Room 109, like the other interview rooms, is bugged to permit the police to overhear and record conversations. After leaving the brothers alone in that room, the police listened to their conversation, and apparently heard and recorded statements by defendant incriminating him in the Chissell murder.2
Defendant moved to suppress the recording and other evidence of the overheard conversation. At the evidentiary hearing, which occurred before our De Lancie decision, defendant emphasized the fact that neither he nor his brother was in custody. The prosecutor in reply asserted that the location of the conversation, not the status of the conversants, was the controlling factor, and that neither brother could expect privacy in a police interview room. The trial court agreed and denied the motion to suppress.
We issued an alternative writ of mandate to consider defendant’s petition in connection with De Lancie, which was then pending before this court. Our De Lancie decision, while upholding a cause of action for injunctive relief, left unsettled questions concerning the suppression of evidence in criminal cases, particularly those in which the challenged monitoring took place before De Lancie was filed. Because we conclude that the De Lancie principles should not apply to conversations monitored before that decision was filed, we do not address whether suppression of evidence is a proper remedy for conversations monitored in violation of De Lancie. We address the retroactivity of De Lancie following our discussion of defendant’s claim that the preferred evidence was seized in violation of federal search and seizure law.
2. Admissibility of the evidence under federal law.
Defendant’s claim that admission of the intercepted conversation violates the Fourth Amendment cannot surmount the decision of the United States Supreme Court in Lanza v. New York (1962) 370 U.S. 139 [8 L.Ed.2d 384, 82 S.Ct. 1218]. The police surreptitiously recorded a visiting room conversation between Lanza and his jailed brother. Lanza later refused to answer questions based on the secret recording in a hearing before a legislative investigating committee. After upholding Lanza’s conviction on independent grounds, the Supreme Court added that in any case Lanza could not rely on the Fourth Amendment in refusing to answer the committee’s questions because the location of the recorded conversation, a jail visiting room, was not a protected area.
[29]*29The court stated that “to say that a public jail is the equivalent of a man’s ‘house’ or that it is a place where he can claim constitutional immunity from search and seizure of his person, his papers, or his effects, is at best a novel argument. To be sure, the Court has been far from niggardly in construing the physical scope of Fourth Amendment protection. A business office is a protected area, and so may be a store. A hotel room, in the eyes of the Fourth Amendment, may become a person’s ‘house,’ and so, of course, may an apartment. An automobile may not be unreasonably searched. Neither may an occupied taxicab. Yet, without attempting either to define or to predict the ultimate scope of Fourth Amendment protection, it is obvious that a jail shares none of the attributes of privacy of a home, an automobile, an office, or a hotel room. In prison, official surveillance has traditionally been the order of the day. Though it may be assumed that even in a jail, or perhaps especially there, the relationships which the law has endowed with particularized confidentiality must continue to receive unceasing protection, there is no claimed violation of any such special relationship here.” (Pp. 143-144 [8 L.Ed.2d at pp. 387-388]; fns. omitted.)3
In 1967, however, Katz v. United States (1967) 389 U.S. 347 [19 L.Ed.2d 576, 88 S.Ct. 507], declared that “the Fourth Amendment protects people not places .... [W]hat [a person] seeks to preserve as private, even in an area accessible to the public, may be constitutionally protected.” (Pp. 351-352 [19 L.Ed.2d at p. 582].) Justice Harlan’s explanation of this language has proved particularly influential. The cases, he stated, establish “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’.” (P. 361 [19 L.Ed.2d at p. 588], conc. opn. of Harlan, J.)
Because Lanza epitomized the “protected areas” type of analysis repudiated by Katz, commentators have questioned whether the earlier decision retains vitality. (See 3 La Fave, Search and Seizure (1978) § 10.9; Giannelli & Gilligan, Prison Searches and Seizures: “Locking” the Fourth Amendment Out of Correctional Facilities (1976) 62 Va.L.Rev. 1045.) Federal courts, however, have consistently followed Lanza and upheld admission of monitored conversations in jails or police stations. “It still appears to be good law that so far as the Fourth Amendment is concerned, jail officials are free to intercept conversations between a prisoner and a visitor. This was the ruling in Lanza v. New York [citation] and it appears to have survived Katz v. United States [citation].” (United States v. Paul (6th Cir. [30]*301980) 614 F.2d 115, 116 [61 A.L.R. Fed. 816], cert. den. 446 U.S. 941; see United States v. Hearst (9th Cir. 1977) 563 F.2d 1331, 1345, cert. den. 435 U.S. 1000, and cases there cited; Christman v. Skinner (2d Cir. 1972) 468 F.2d 723, 726.)
There are signs that the federal courts may move away from Lanza’s total rejection of privacy in a jail or police station, and may ultimately adopt the De Lancie position limiting evesdropping to that required for institutional security. In Bonner v. Coughlin (1975) 517 F.2d 1311 [32 A.L.R.Fed. 585], certiorari denied 435 U.S. 932 [55 L.Ed.2d 529, 98 S.Ct. 1507], Justice Stevens, writing for the Seventh Circuit, stated that although “the justifiable reasons for invading an inmate’s privacy are both obvious and easily established[,] [w]e are persuaded . . . that the surrender of privacy is not total and that some residuum meriting the protection of the Fourth Amendment survives the transfer into custody.” (P. 1316.) And United States v. Hearst, supra, 563 F.2d 1331, described the post-Katz cases as permitting only “[a]n intrusion by jail officials pursuant to a rule or policy with a justifiable purpose of imprisonment or prison security” (p. 1345), but upheld the evidence in that case on the ground that “[h]ere the government adequately established that its practice of monitoring and recording prisoner-visitor conversations was a reasonable means of maintaining prison security.” (P. 1346.)
Despite these precursors, no federal case has repudiated the Lanza dictum or excluded a jail or police station conversation from evidence. (See 3 La Fave, op. cit. supra, § 10.9, p. 418.) If occasional state court cases such as De Lancie take a different course, they do so on state, not federal, grounds. Bound in matters of federal law by the United States Supreme Court, which has never rejected its dictum in Lanza v. New York, and influenced by the decisions of the lower federal courts, we are impelled to conclude that the Lanza dictum continues to control in federal law.
Under Lanza, the fact that neither defendant nor his brother was in custody does not advance defendant’s claim. Lanza does not rest upon the concept that a prisoner loses civil rights upon arrest or conviction. (Lanza himself was a visitor at the jail, not an inmate.) The decision, instead, asserts that there is no right of privacy—in post-Katz terminology, no justifiable expectation of privacy—in detention facilities, regardless whether the particular defendant involved was detained or voluntarily present.
3. Admissibility of the evidence under pre-De Lancie California law.
California decisions before De Lancie followed the pattern of the federal decisions, admitting the challenged evidence in virtually all cases. In the leading case, North v. Superior Court, supra, 8 Cal.3d 301—the only case [31]*31to exclude a monitored conversation—North was detained in jail awaiting trial. When his wife came to visit him in jail, Detective Neesan invited them into his private office, left them there with the door closed, and secretly monitored their conversation. North sought to exclude the conversation on two grounds: unreasonable search under the state and federal Constitutions, and violation of the privilege extended by Evidence Code section 980 to confidential marital communications.
Our opinion first noted that “prior California cases have uniformly held that an inmate of a jail ordinarily has no right of privacy.” (P. 308.) Even marital communications, we explained, were not protected: “[i]n view of the general rule that an inmate of a jail or prison has no reasonable expectation of privacy, ... an ordinary jailhouse conversation between spouses could not be deemed to have been ‘made in confidence, ’ as required by Evidence Code section 980 . . . .” (P. 311.)
North went on, however, to observe that the conversation in question occurred “under circumstances which strongly indicate that petitioner and his wife were lulled into believing that their conversation would be confidential. Although the record does not disclose whether or not Neesan made any representations to that effect, his admitted conduct spoke as clearly as words—first by surrendering to petitioner and his wife Neesan’s own private office so that they might converse and then by exiting and shutting the door, leaving them entirely alone. Certainly, nothing in Neesan’s actions indicated that petitioner’s conversation would be monitored. The foregoing circumstances, coupled with the statutory presumption that a conversation between spouses is presumed to have been made in confidence (Evid. Code, § 917 . . .), constituted a sufficient showing by petitioner to establish a reasonable expectation of privacy. ’ ’ (Pp. 311-312.)
We concluded by emphasizing “that nothing in our opinion should be deemed a disapproval of the common practice of monitoring inmates’ conversations with others, including their spouses, in visiting rooms or similar places. That practice seems reasonably necessary in order to maintain jail security and (with the exceptions set forth in Pen. Code, § 636, supra), is not proscribed by law.” (P. 312, fn. omitted.)
The North opinion stood on two grounds: the marital privilege and the deliberate creation of an expectation of privacy. In the following year the Court of Appeal addressed the question whether the creation of an expectation of privacy alone would require exclusion. In People v. Finchum (1973) 33 Cal.App.3d 787 [109 Cal.Rptr. 319], the sheriff put two codefendants in an interview room and asked, “ ‘[I]f I left them together for ten or fifteen minutes, could they get their stories straight ...?’” (P. 789.) [32]*32He then went to another room to monitor the conversation. Reversing an order suppressing evidence, the court stated that “the defendant and his companion did not occupy a privileged status. In North it was the husband-wife relationship coupled with Detective Neesan’s conduct that gave rise to the expectation of privacy. Absent the privileged relationship from the North case, as we read that case, there would have been no reasonable expectation of privacy.” (P. 791.)
During the 10 years following North, all attempts to suppress conversations based upon unprivileged relationships failed. (See In re Joseph A. (1973) 30 Cal.App.3d 880, 885-886 [106 Cal.Rptr. 729] (defendant’s conversation with his uncle in police interview room); People v. Fonville (1973) 35 Cal.App.3d 693, 707 [111 Cal.Rptr. 53] (defendant’s conversation with his uncle in police interview room); People v. Martinez (1978) 82 Cal.App.3d 1, 15 [147 Cal.Rptr. 208] (defendant’s jailroom conversation with his brother and sister); People v. Estrada (1979) 93 Cal.App.3d 76, 99 [155 Cal.Rptr. 731] (defendant’s conversation with his sister in jail visiting room); People v. Owens (1980) 112 Cal.App.3d 441, 448-449 [169 Cal.Rptr. 359] (codefendants in jail interview room); People v. Dominguez (1981) 121 Cal.App.3d 481, 505 [175 Cal.Rptr. 445] (codefendant and his mother in jail visiting room).) Even marital communications were held admissible absent unusual circumstances demonstrating a deliberate attempt to create an expectation of privacy. (People v. Hill (1974) 12 Cal.3d 731, 765 [117 Cal.Rptr. 393, 528 P.2d 1] (conversation in jail visiting room);
Defendant nevertheless argues that his motion to suppress should be granted under pr e-De Lancie law. He cannot predicate his claim on the family relationship, for communications between brothers are not privileged under the Evidence Code. And under the post -North cases, merely leaving the communicants alone in a room was not considered an improper attempt to create an expectation of privacy. (People v. Finchum, supra, 33 Cal.App.3d 787, 791; In re Joseph A., supra, 30 Cal.App.3d 880, 885-886.) He therefore stresses the unique aspect of his case: the fact that neither he nor his brother was under arrest at the time of their conversation.
In upholding the admission of intercepted conversations, the pre-De Lancie California cases do not clearly distinguish whether the crucial factor is [33]*33the status of the speakers—at least one being an inmate or detainee—or the location of the conversation in a jail or police station. Federal cases involving searches antedating Katz v. United States, supra, 389 U.S. 347, had emphasized the place of the conversation (see Lanza v. New York, supra, 370 U.S. 139, 143-144 [8 L.Ed.2d 384, 387-388]; Christman v. Skinner, supra, 468 F.2d 723, 726; Williams v. Nelson, supra, 457 F.2d 376, 377); older California cases proclaimed instead that a prisoner has no right of privacy (see People v. Lopez (1963) 60 Cal.2d 223, 248 [32 Cal.Rptr. 424, 384 P.2d 16]; People v. Morgan (1961) 197 Cal.App.2d 90, 93 [16 Cal.Rptr. 838]).4 After Katz, however, all cases talked in terms of the effect of the location of the conversation or the speaker’s status on whether he could reasonably and justifiably expect privacy.5
The fundamental premise underlying all these decisions upholding admissibility was that routine monitoring of police station and jail conversations was necessary for institutional security, and consequently that society should not recognize any expectation of privacy which would impede that activity. Prior to De Lancie, the fact that a particular conversation was monitored not for security purposes but to gather evidence did not argue against admissibility.6 (See Henry, Electronic Surveillance in California Prisons After De Lancie v. Superior Court (1982) 22 Santa Clara L.Rev. 1109, 1112-1116.) The cases evince no reliance on the speaker’s lack of awareness of the pervasive practice of monitoring conversations in jail or [34]*34in the police station,7 and thus undertake no real attempt to assess the reasonableness of his expectation of privacy. Instead they state a legal fiction: that no one can reasonably expect privacy in a jail or police station unless the conversation is protected by an evidentiary privilege.
The foregoing review of pre-De Lancie California cases does not support the present defendant’s claim that police interception of the conversation between him and his brother violated their right of privacy under then-existing California law. It is true that many cases spoke of persons in custody lacking a “right” of privacy, but the underlying rationale of that language was that monitoring conversations by such persons is essential to institutional security. That rationale applied equally to all persons admitted to and left alone in an interview or other interior room of the police station, whether or not they have been arrested. Thus, under pr e-De Lancie California law, the Donaldsons’ expectation of privacy would be unreasonable as a matter of law.
4. The effect and retroactivity of De Lancie.
Defendant contends that our De Lancie decision recognized that a person in jail or a police station may have a reasonable expectation of privacy and, to protect such expectations, limited police monitoring to that necessary to protect institutional security. He claims that under this standard, the police recording of the conversation with his brother was unlawful. Finally, defendant maintains that such evidence, obtained in violation of De Lancie, should be suppressed even though the recording was made before De Lancie was rendered.
In reviewing defendant’s arguments, we first consider the effect of De Lancie upon prior California law. Then, avoiding any decision as to whether De Lancie requires the exclusion of evidence obtained after that case was filed, we turn directly to the question of retroactivity. Our conclusion that De Lancie does not apply to antecedent searches is dispositive of this case.
De Lancie itself was a civil action for injunctive relief, prompted by disclosures at the Patty Hearst trial (see United States v. Hearst, supra, 563 F.2d 1331) revealing that personnel at the San Mateo County jail were routinely monitoring conversations between visitors and pretrial detainees. We held that allegations charging that such monitoring was conducted for purposes other than institutional security stated a cause of action. (De Lan[35]*35cie v. Superior Court, supra, 31 Cal.3d 865, 877.) That holding necessarily implied that secret monitoring of conversations between detainees and visitors, “undertaken for the purpose of gathering evidence for use in criminal proceedings, rather than to maintain the security of the jail” (id.), was unlawful.
The De Lancie decision relied largely on Penal Code sections 2600 and 2601, which restored certain civil rights to prisoners, including the right “to have personal visits [subject to] such restrictions as are necessary for the reasonable security of the institution.” (§ 2601.)8 Principles of equal protection, we explained, required that pretrial detainees receive the same rights as those accorded by statute to prisoners. (31 Cal.3d at p. 872.)
Since Donaldson and his brother were neither prisoners nor detainees, and had never been deprived of any civil rights, De Lancie’& statutory analysis is largely irrelevant to the present case. What is crucial is De Lancie’s discussion of North v. Superior Court, supra, 8 Cal.3d 301. Defendants in De Lancie relied on North for the proposition that ordinarily there can be no reasonable expectation of privacy in a jail or police station, and asserted that consequently routine monitoring of detainee-visitor conversations violated no expectation of privacy. Our rejection of that proposition was essential to the De Lancie decision.
Three considerations led us to reject the reasoning of North. First was the obvious need of persons confined in jail to communicate in private with their spouses, families, and friends about matters often of a confidential or intimate nature. Permitting state officials to listen in on such conversations for reasons unrelated to jail security—indeed without any reason at all— offends the fundamental right of privacy guaranteed by the California Constitution. (Cal. Const., art. I, § 1.)
Second, sections 2600 and 2601 enacted a policy of restoring to inmates those civil rights compatible with prison security. The purpose of that policy would be defeated if we were to hold that no one within a jail or police station—inmate or not—has any right or expectation of privacy. (See 31 Cal.3d at pp. 875-876.)
[36]*36Finally, we observe that North and similar cases did not purport to make a factual determination that inmates do not subjectively expect privacy, or that such expectations are unreasonable, but simply declared a legal proposition, the absence of any right of privacy in jail. (P. 875.) As a realistic matter, persons placed in a setting where they could be overheard only through the use of hidden microphones or tapped telephone wires often do expect privacy. And unless those persons actually know of police monitoring practices or of court decisions authorizing those practices, we could, not describe their expectation as unreasonable. Indeed from the cases which have come to our attention, it appears that an expectation of privacy in a police station or jail whenever the conversation cannot be overheard by unaided ears is so commonly entertained that the police anticipate and routinely exploit it to obtain evidence of crimes.
In short, De Lancie held that the “no expectation of privacy in a police station or jail” doctrine of North v. Superior Court could not be justified either as a measure of the conversant’s subjective belief or as a judgment on the reasonableness of that belief. The monitoring of conversations could be upheld only when supported by an overriding state interest of sufficient magnitude to justify invading the privacy of the persons monitored. Drawing upon Penal Code section 2601, we approved monitoring to safeguard “the reasonable security of the institution,” but held that allegations charging the county with routinely monitoring detainee-visitor conversations for the sole purpose of gathering evidence stated a cause of action.
In the present case, the testimony suggests that the police secretly recorded the Donaldson brothers’ conversations to acquire leads or evidence about the murder, not to protect the security of the police station. The district attorney here does not claim the monitoring complies with the De Lancie decision. He argues instead that De Lancie, a civil action for injunctive relief, should not be extended to require the suppression of evidence in a criminal proceeding, and that in any event it should not apply to police conduct that took place before De Lancie was rendered. As we mentioned earlier, we decide this case on the second ground, holding that De Lancie does not affect the validity of antecedent searches, and avoid any determination of the effect of De Lancie upon police monitoring after that decision was filed.
In determining whether a decision should be given retroactive effect, the California courts undertake first a threshold inquiry, inquiring whether the decision established new standards or a new rule of law. If it does not establish a new rule or standards, but only elucidates and enforces prior law, no question of retroactivity arises. (See United States v. Bowen (9th Cir. 1974) 500 F.2d 960, 975; People v. Jones (1980) 108 Cal.App.3d 9, [37]*3716 [166 Cal.Rptr. 131] and cases there cited.) Neither is there any issue of retroactivity when we resolve a conflict between lower court decisions, or address an issue not previously presented to the courts. In all such cases the ordinary assumption of retrospective operation (County of Los Angeles v. Faus (1957) 48 Cal.2d 672, 680-681 [312 P.2d 680]; Wellenkamp v. Bank of America (1978) 21 Cal.3d 943, 953-954 [148 Cal.Rptr. 379, 582 P.2d 970]) takes full effect. Thus, we must undertake a threshold inquiry to determine whether De Lancie established a “new” rule or standard which could be given nonretroactive application.
The United States Supreme Court has recently attempted to define the decisions involving a “clear break with the past” (Desist v. United States (1964) 394 U.S. 244, 248 [22 L.Ed.2d 248, 254, 89 S.Ct. 1030]) that raise an issue of retroactivity. According to United States v. Johnson (1982) 457 U.S. 537 [73 L.Ed.2d 202, 102 S.Ct. 2579], “[s]uch a break has been recognized only when a decision explicitly overrules a past precedent of this Court [citations], or disapproves a practice this Court has arguably sanctioned in prior cases [citations], or overturns a longstanding and widespread practice to which this Court has not spoken, but which a near-unanimous body of lower court authority has expressly approved.” (457 U.S. 537 at p. 551 [73 L.Ed.2d at p. 215, 102 S.Ct. at p. 2588].)
While De Lancie did not expressly overrule any prior decision, it disapproved a practice arguably sanctioned by North v. Superior Court, supra, 8 Cal.3d 301, and many other decisions. Although based in part on an interpretation of two 1975 statutes, Penal Code sections 2600 and 2601, De Lancie was clearly not a simple application of the statutory language. Prior cases had held that at least as to nonprivileged conversations there existed no right of privacy in a jail or police station, and if that doctrine prevailed, mere application of the language of sections 2600 and 2601 would offer no protection. Thus, in its departure from past precedent, even though in the context of statutory interpretation, De Lancie appears to represent the type of break from prior law which may justify nonretroactivity under United States v. Johnson.9
[38]*38Once resolved that a decision establishes a new standard, the California courts define the retroactive effect of that decision under the tripartite test based upon Stovall v. Denno, supra, 388 U.S. 293. People v. Kaanehe (1977) 19 Cal.3d 1 [136 Cal.Rptr. 409, 559 P.2d 1028], explains the California practice: “Whether a judicial decision establishing new . . . standards is to be given retroactive effect is customarily determined by weighing the following factors: ‘(a) the purpose to be served by the new standards, (b) the extent of reliance by law enforcement authorities on the old standards, and (c) the effect on the administration of justice of retroactive application of the new standards.’ (Stovall v. Denno (1967) 388 U.S. 293, 297 [18 L.Ed.2d 1199, 1203]; accord, In re Johnson (1970) 3 Cal.3d 404, 410 [90 Cal.Rptr. 569, 475 P.2d 841].) ‘It is also clear that the factors of reliance and burden on the administration of justice are of significant relevance only when the question of retroactivity is a close one after the purpose of the new rule is considered.’ (In re Johnson, supra, 3 Cal.3d 404, 410.) Decisions have generally been made fully retroactive only where the right vindicated is one which is essential to the integrity of the fact-finding process. On the other hand, retroactivity is not customarily required when the interest to be vindicated is one which is merely collateral to a fair determination of guilt or innocence. [Citation.]” (19 Cal.3d at p. 10; accord, In re Joe R. (1980) 27 Cal.3d 496, 511 [165 Cal.Rptr. 837, 612 P.2d 927].)10
In search and seizure cases, the tripartite test leads generally to the conclusion that a decision should not be given retroactive effect.11 As ex[39]*39plained in Kaanehe, in such a case “[exclusion is not necessary to ensure the reliability of the fact-finding process at trial. No compulsion is present and the evidence seized is entirely trustworthy. As the purpose of the exclusionary rule in those circumstances is to deter illegal conduct by law enforcement officials, exclusion of evidence seized prior to the pronouncement of a decision does not further compliance with that decision.” (19 Cal.3d 1, 10-11; accord, In re Joe R., supra, 27 Cal.3d 496, 511-512; see People v. Cook, supra, 22 Cal.3d 67, 99, fn. 18; People v. Ramey, supra, 16 Cal.3d 263, 276, fn. 7; People v. Superior Court (Harris) (1979) 100 Cal.App.3d 386, 389 [160 Cal.Rptr. 880].)
Consequently, even if we were to require the suppression of evidence seized in violation of the De Lancie standards, we would not apply that rule to evidence derived from pre-De Lancie searches. The purpose of the De Lancie decision was to limit clandestine police monitoring in order to protect the private communications of inmates, detainees and visitors. Whether or not an exclusionary sanction is necessary to achieve that purpose, retroactive application of such a sanction would serve no constructive purpose; it would not restore the privacy of those whose innocent conversations had been monitored, but would benefit only those who made incriminating admissions. Neither would it add to the deterrent effect of the De Lancie decision upon future monitoring. Therefore, in view of the reliance of the police upon pre-De Lancie searches, we conclude that De Lancie does not require the exclusion of evidence obtained in antecedent searches.
Defendant having failed to show an adequate basis for suppression of the challenged evidence under either federal or California law, the alternative writ of mandate is discharged, and the petition for a peremptory writ is denied.
Kaus, J., and Grodin, J., concurred.
Overruled on other grounds in People v. De Vaughn (1977) 18 Cal.3d 889, 896, footnote 5 [135 Cal.Rptr. 786, 558 P.2d 872],