In this criminal case, the prosecution seeks to justify the warrantless police search of defendant’s garage and the warrant-less seizure of evidence in the garage on the ground that defendant’s brother, who resided with defendant, had agreed as a condition of probation to submit to warrantless searches. The majority rejects this argument, concluding that the warrantless search of defendant’s garage violated the protection of the federal Constitution’s Fourth Amendment against unreasonable searches and seizures and that the evidence seized in that search should have been excluded at trial.
The majority reaches this conclusion by distinguishing, not without some effort, two decisions by this court from which I dissented. One of them—In re Tyrell J. (1994) 8 Cal.4th 68 [32 Cal.Rptr.2d 33, 876 P.2d 519]—held that police may rely on a probation search condition of which they are unaware to justify an otherwise illegal warrantless search of the probationer. The other—People v. Woods (1999) 21 Cal.4th 668 [88 Cal.Rptr.2d 88, 981 P.2d 1019]—held that a search condition may be used to justify a search whose purpose is to gather evidence against a person not subject to the search condition.
I concur in the majority’s conclusion, but reach that result by following the different and simpler path marked by my previous dissents. For two independent reasons, the search here violated the Fourth Amendment. First, the search was illegal because the police officers who searched defendant’s *803garage were completely unaware of the brother’s probation search condition. As I explained in my dissent in In re Tyrell J., supra, 8 Cal.4th 68, 90, under the Fourth Amendment the police may not rely ón a probation search condition of which they are unaware to justify a warrantless search. To permit them to do so, thereby encouraging them to “search first and ask questions later,” is completely at odds with the Fourth Amendment’s purpose of protecting persons and their possessions against unreasonable government intrusion. (Tyrell J., at p. 98 (dis. opn. of Kennard, J.).)
Second, the search was illegal because the purpose of the search was to gather evidence against defendant, not his brother who alone was subject to the probation search condition. As I explained in my dissent in People v. Woods, supra, 21 Cal.4th 668, 682, the Fourth Amendment does not permit “police to use a probation search condition, which authorizes the warrant-less, suspicionless search of a probationer, as authority to search a home for the express purpose of seeking evidence against nonprobationers who share the residence with the probationer.”
BROWN, J.I concur in the determination to affirm the Court of Appeal’s judgment reversing the denial of defendant’s suppression motion.
I write separately in part because the majority concludes its discussion regarding Armando Robles’s probation search condition by speculating that “the advance consent might have furnished a legitimate basis for the search and seizure had the officers known of it at the time they acted . . . .” (Maj. opn., ante, at p. 800.) For the reasons set forth in my dissenting opinion in People v. Woods (1999) 21 Cal.4th 668, 683-696 [88 Cal.Rptr.2d 88, 981 P.2d 1019], I would dispute the constitutional viability of this conclusion.
I am also prompted by the remark of respondent’s counsel at oral argument that upholding the instant search simply follows from the “logical application” of cases decided by this court. In People v. Woods, a majority approved the warrantless search of the defendants’ bedroom based upon the probation search condition of a cotenant, applying a third party consent rationale. {People v. Woods, supra, 21 Cal.4th at pp. 675-676.) In In re Tyrell J. (1994) 8 Cal.4th 68, 89 [32 Cal.Rptr.2d 33, 876 P.2d 519] (Tyrell J.), the court upheld the search of a juvenile probationer even though the officer did not know he was subject to a search condition, because the juvenile had no reasonable expectation of privacy under the circumstances. Since Armando had consented to a search of their residence when he accepted probation on that condition, the Attorney General argues defendant assumed the risk of a third party consent and had no reasonable expectation of privacy. The officer’s ignorance of the condition, or even of Armando’s probationary status, was thus immaterial. QED.
*804The Attorney General’s assessment of the confluence of People v. Woods, supra, 21 Cal.4th 668, and Tyrell J. is as syllogistically accurate as it is constitutionally shocking. It also speaks volumes to how far this court’s Fourth Amendment methodology has strayed from the core rationale of the guarantee against unreasonable searches and seizures.
The analytical vice of Tyrell J. is the majority’s assumption that the two-part inquiry into the defendant’s reasonable expectation of privacy derived from Justice Harlan’s concurring opinion in Katz v. United States (1967) 389 U.S. 347, 360 [88 S.Ct. 507, 516, 19 L.Ed.2d 576],1 serves as an all-purpose or universally applicable template for assessing Fourth Amendment challenges. But it does not. Decisions in which the United States Supreme Court has utilized the Katz approach have generally concerned whether the place searched or the manner in which police officers conducted the search violated the defendant’s right to be free of unreasonable searches and seizures.2 (See also Rakas v. Illinois, supra, 439 U.S. at p. 143 [99 S.Ct. at p. 430] [finding Katz “provides guidance in defining the scope of the interest protected by the Fourth Amendment” for purposes of determining whether defendant may contest search or seizure]; see generally 1 LaFave, Search and Seizure (3d ed. 1996) § 2.1, pp. 375-395.) In some cases, the issue distilled to the fundamental query whether law enforcement had even conducted a search. (See 1 LaFave, Search and Seizure, supra, § 2.2, pp. 395-464.)
For example, the seminal decision of Katz v. United States, supra, 389 U.S. 347, involved recording of the defendant’s side of a conversation in a public telephone booth by an electronic listening device. The government *805contended this did not amount to a search because no physical intrusion occurred and the defendant did not occupy a “ ‘constitutionally protected area.’” {Id. at p. 351 [88 S.Ct. at p. 511].) The court rejected these arguments with the now-familiar observation that “the Fourth Amendment protects people, not places.” {Ibid.) To this observation, Justice Harlan rejoined, “The question, however, is what protection it affords to those people. Generally, as here, the answer to that question requires reference to a ‘place.’ ” {Id. at p. 361 [88 S.Ct. at p. 516] (cone. opn. of Harlan, J.).) His “twofold requirement” that currently serves as the standard analytical rubric immediately followed this statement and must be understood in light thereof. {Ibid.)
Tyrell J., supra, 8 Cal.4th 68, did not involve the search of a place but of the defendant’s person. In the latter circumstance, the Supreme Court resolves a Fourth Amendment challenge not by applying the Katz two-part inquiry but by analyzing the question as one of reasonableness. (See, e.g., Terry V. Ohio (1968) 392 U.S. 1, 15-23 [88 S.Ct. 1868, 1876-1881, 20 L.Ed.2d 889].) Katz has no relevance to the search of a person because, as a general proposition, society is always “prepared to recognize as ‘reasonable’ ” (Katz v. United States, supra, 389 U.S. at p. 361 [88 S.Ct. at p. 516] (cone. opn. of Harlan, J.)) an expectation of privacy in one’s person. While Katz “provides guidance in defining the scope of the interest protected by the Fourth Amendment” (Rakas v. Illinois, supra, 439 U.S. at p. 143 [99 S.Ct. at p. 430]), this reference is to the spatial scope: “[T]he Court in Katz held that capacity to claim the protection of the Fourth Amendment depends not upon a property right in the invaded place but upon whether the person who claims the protection of the Amendment has a legitimate expectation of privacy in the invaded place.” (Ibid., italics added.)
This is not to say that consideration of a defendant’s expectation of privacy has no bearing upon whether a search of the person was reasonable. (See, e.g., Terry v. Ohio, supra, 392 U.S. at p. 9 [88 S.Ct. at p. 1873].) The flaw of Tyrell J. is that it puts the reasonable expectation of privacy cart before the horse. (Cf. Lorenzana v. Superior Court (1973) 9 Cal.3d 626, 637-638 [108 Cal.Rptr. 585, 511 P.2d 33].) Tyrell J. involved an exception to the warrant requirement: the juvenile probationer was subject to a search condition and knew he could be searched without probable cause. As with any exception, the reasonableness of a search predicated on such a condition must be measured in relation to the rationale for excusing compliance with Fourth Amendment strictures. (See generally People v. Woods, supra, 21 Cal.4th 668, 692-696 (dis. opn. of Brown, J.).) The defendant’s reasonable expectation of privacy may be factored into one or more of several considerations, such as whether the rationale actually supports dispensing with the warrant requirement. (See, e.g., Marshall v. Barlow’s, Inc. (1978) 436 U.S. *806307, 312-313 [98 S.Ct. 1816, 1820-1821, 56 L.Ed.2d 305].) It does not define the inquiry into the reasonableness of the search, however, because that inquiry looks first to the officer’s conduct under the circumstances. When the prosecution relies on a probationer’s search condition to justify the reasonableness of a warrantless search, the officer must have acted pursuant to that justification, which he can only reasonably do if he has knowledge of the condition. (See Tyrell J., supra, 8 Cal.4th 68, 97 (dis. opn. of Kennard, J.); People v. Bravo (1987) 43 Cal.3d 600, 610 [238 Cal.Rptr. 282, 738 P.2d 336]; In re Anthony S. (1992) 4 Cal.App.4th 1000, 1004 [6 Cal.Rptr.2d 214].) Any other course is an open invitation to abuse. (Cf. Terry v. Ohio, supra, 392 U.S. at pp. 14-15 [88 S.Ct. at p. 1876].)
The reasoning of Tyrell J. has also not escaped criticism among the " commentators: “Whatever might be concluded about the necessity to permit the police to play some role in the enhanced scrutiny to be directed at those on probation and parole, quite obviously there is no rational basis upon which to uphold otherwise illegal police searches of persons only later determined to be on probation or parole. . . . Regrettably, that eminently sound position was later abandoned in In re Tyrell J. on the bizarre reasoning that a probationer who knows that he is subject to ‘a valid search condition’ to his release consequently ‘does not have a reasonable expectation of privacy over his person or property’ vis-a-vis any search by anyone, including a search by a police officer unaware of the probationer status! As the dissent in Tyrell J. aptly noted, that strange conclusion, without precedent in any jurisdiction, gives police an incentive to make searches even without probable cause because, should it turn out that the suspect is a probationer, the evidence will be admissible nonetheless.” (4 LaFave, Search and Seizure, supra, § 10.10(e), pp. 791-792, fns. omitted; see also Comment, Fourth Amendment Protection for Juvenile Probationers in California, Slim or None?: In re Tyrell J. (1995) 22 Hastings Const. L.Q. 893.)
By succumbing to the trap of the facile formula that beguilingly substitutes for critical analysis, the court in Tyrell J. reached a constitutionally suspect conclusion. For that reason, we should avoid endorsing, and thus perpetuating, its dubious reasoning.
“[F]irst [whether] a person [has] exhibited an actual (subjective) expectation of privacy and, second, [whether] the expectation be one that society is prepared to recognize as ‘reasonable.’ ” (Katz v. United States, supra, 389 U.S. at p. 361 [88 S.Ct. at p. 516] (cone. opn. of Harlan, J.).)
See, e.g., Bond v. United States (2000) 529 U.S. 334, 338 [120 S.Ct. 1462, 1465, 146 L.Ed.2d 365] (manipulation of defendant’s carry-on luggage located in overhead storage space); Minnesota v. Carter (1998) 525 U.S. 83, 88 [119 S.Ct. 469, 472, 142 L.Ed.2d 373] (observations of defendants packaging drags in apartment they only momentarily occupied for that purpose); Minnesota v. Olson (1990) 495 U.S. 91, 95-96 [110 S.Ct. 1684, 1687, 109 L.Ed.2d 85] (warrantless arrest of overnight guest); California v. Greenwood (1988) 486 U.S. 35, 39 [108 S.Ct. 1625, 1628, 100 L.Ed.2d 30] (search of defendant’s trash container that had been placed at curb for garbage collection); O’Connor v. Ortega (1987) 480 U.S. 709, 716 [107 S.Ct. 1492, 1497, 94 L.Ed.2d 714] (search of defendant’s workplace); California v. Ciraolo (1986) 476 U.S. 207, 211 [106 S.Ct. 1809, 1811, 90 L.Ed.2d 210] (police observation of defendant’s fenced backyard from airplane 1,000 feet overhead); Rawlings v. Kentucky (1980) 448 U.S. 98, 104 [100 S.Ct. 2556, 2561, 65 L.Ed.2d 633] (search of companion’s purse); Smith v. Maryland (1979) 442 U.S. 735, 739-741 [99 S.Ct. 2577, 2579-2581, 61 L.Ed.2d 220] (use of pen register to record defendant’s outgoing calls); Rakas v. Illinois (1978) 439 U.S. 128, 143 [99 S.Ct. 421, 430, 58 L.Ed.2d 387] (search of glove compartment of car in which defendants were passengers).