dissenting.
The majority assumes without deciding that Agent Peterson’s affidavit failed to establish probable cause for the May 25, 2000, search of an apartment at 2234 Wal-cott Place in Richmond. The majority then holds that the evidence from that search can nonetheless be admitted under the good faith exception established by United States v. Leon, 468 U.S. 897, 104 S.Ct. 3405, 82 L.Ed.2d 677 (1984), because Agent Peterson’s affidavit was not “so lacking in indicia of probable cause as to render official belief in its existence entirely unreasonable.” Id. at 923, 104 S.Ct. 3405 (internal quotation marks and citation omitted). I respectfully disagree. The warrant here must stand or fall on the veracity of the confidential informant, and neither the bare bones assertions of the informant’s reliability in paragraph 5 of the agent’s affidavit nor the corroboration provided in paragraphs 3, 4, and 6 come close to establishing the informant’s veracity. As a result, I would affirm the district court’s order suppressing the evidence from the May 25 search because Agent Peterson should have “known that the search was illegal despite the magistrate’s authorization.” Id. at 922 n. 23, 104 S.Ct. 3405. Indeed, a reasonably well-trained officer would never have submitted Agent Peterson’s affidavit to the magistrate judge in the first place. See Malley v. Briggs, 475 U.S. 335, 345, 346 n. 9, 106 S.Ct. 1092, 89 L.Ed.2d 271 (1986). Because I think Agent Peterson’s affidavit was too insubstantial to merit application of the good faith exception, I must also discuss an alternative argument advanced by the government. According to the government, the exception applies in this case because Agent Peterson knew, but did not tell the magistrate, that his confidential source was the same informant referred to *202in another officer’s affidavit that had supported a warrant for an earlier search of the same apartment on February 10, 2000. I conclude that what Agent Peterson knew but failed to tell the magistrate is irrelevant to Peterson’s good faith because Leon requires an officer to have an objectively reasonable belief that his affidavit gave the magistrate a substantial basis for finding probable cause. Whether this belief is reasonable can depend only on the facts presented to the magistrate.
I.
In deciding whether Agent Peterson’s affidavit was so lacking in indicia of probable cause that no reasonable officer would have submitted it to a magistrate, we must view the affidavit in the light of the totality-of-the-circumstances test for probable cause established by the Supreme Court in Illinois v. Gates, 462 U.S. 213, 103 S.Ct. 2317, 76 L.Ed.2d 527 (1983). Under Gates “[t]he task of the issuing magistrate is simply to make a practical, common-sense decision whether, given all the circumstances set forth in the affidavit before him, including the ‘veracity’ and ‘basis of knowledge’ of persons supplying hearsay information, there is a fair probability that contraband or evidence of a crime will be found in a particular place.” Id. at 238, 103 S.Ct. 2317. The task of a reviewing court is to “ensure that the magistrate had a substantial basis for concluding that probable cause existed.” Id. at 238-39, 103 S.Ct. 2317 (internal quotation marks, ellipsis, and citation omitted). Although Gates abandoned the two-pronged test set forth in Aguilar v. Texas, 378 U.S. 108, 84 S.Ct. 1509, 12 L.Ed.2d 723 (1964), and Spinelli v. United States, 393 U.S. 410, 89 S.Ct. 584, 21 L.Ed.2d 637 (1969), it was not a repudiation of all that had gone before. Specifically, the Gates Court continued to insist that a magistrate’s probable cause determination must be based on evidence that is both substantial and independent. “Sufficient information must be presented to the magistrate to allow that official to determine probable cause; his action cannot be a mere ratification of the bare conclusions of others.” Gates, 462 U.S. at 239, 103 S.Ct. 2317 (emphasis added). When an affidavit fails to provide the magistrate with a substantial and independent basis for concluding that probable cause exists, any warrant issued on the basis of that affidavit cannot be relied upon in good faith.
Paragraph 7 of Agent Peterson’s affidavit, ante at 194, states that the confidential informant had been inside Bynum’s apartment at 2234 Walcott Place within the last 72 hours and had observed Bynum preparing “a large quantity of heroin” for distribution. If credible, this information shows that the informant had a sufficient basis of knowledge to establish probable cause for the May 25 search. Conversely, if the information in paragraph 7 is not credible, the affidavit falls so far short of establishing probable cause that no reasonable officer would have submitted it to a magistrate. Thus, the critical question in this ease is whether an objectively reasonable officer would have believed that Agent Peterson’s affidavit provided the magistrate with a substantial and independent basis for concluding that the confidential informant was credible. The government argues that the credibility of the informant in Agent Peterson’s affidavit is supported by (a) the agent’s claims about the informant’s reliability in paragraph 5 and (b) the corroboration of the informant’s tip in paragraphs 3, 4, and 6. Neither provided the magistrate with a substantial and independent basis for crediting the informant’s *203claims that are reported in paragraph 7.1
A.
The first sentence in paragraph 5 attempts to establish the confidential informant’s veracity by pointing to his track record. It states:
Information and intelligence provided in this investigation by a Confidential Source (CS) has been proven reliable and information provided to law enforcement has been verified.
The bar for establishing an informant’s veracity through references to his track record is not high. For example, courts have uniformly held that an informant’s veracity is adequately established when the affiant asserts that the informant has supplied information leading to arrests and convictions. See, e.g., United States v. King, 227 F.3d 732, 742 (6th Cir.2000); United States v. Shepherd, 714 F.2d 316, 317 (4th Cir.1983). At the opposite end of the spectrum, it is equally clear that a bare bones, conclusory assertion that the informant is credible or his information reliable is not sufficient because it “gives the magistrate virtually no basis at all for making a judgment regarding probable cause.” Gates, 462 U.S. at 239, 103 S.Ct. 2317. We held in United States v. Wilhelm, 80 F.3d 116 (4th Cir.1996), that Leon’s good faith exception does not apply when a warrant is issued on the basis of a bare bones affidavit. Id. at 121. Here, Agent Peterson’s affidavit says only that the informant had provided information that had proven reliable and had been verified. It does not say whether the information led to arrests or convictions, how important the information was in prior investigations, or whether the information pertained to the same sorts of crimes. In short, Agent Peterson’s characterization of the informant as having provided reliable and verified information is unacceptably conclusory because it still “ ‘leaves the nature of [the informant’s past] performance undisclosed, so that the judicial officer making the probable cause determination has no basis for judging whether the [affiant’s] characterization of [the informant’s past] performance is justified.’ ” United States v. Foree, 43 F.3d 1572, 1576 (11th Cir.1995) *204(quoting 1 Wayne R. LaFave, Search and Seizure § 3.3(b) at 636 (2d ed.1987)). Many courts have properly held that a bare assertion that an informant has provided reliable information in the past carries little or no w.eight in the probable cause determination. See, e.g., United States v. Brack, 188 F.3d 748, 755 (7th Cir.1999) (holding that an affidavit stating that the affiants “ha[d] received reliable information from a credible person” was so conclusory that the tip would be treated as though it had been “obtained from an informant of ‘unknown reliability’ ”); Foree, 43 F.3d at 1575-76 (holding that an affidavit stating that “[information previously provided by the [confidential informant] ha[d] been corroborated by the affiant” and that the informant “ha[d] been found to be truthful and accurate in other narcotics trafficking intelligence” was entitled to only “slight weight”). The same reasoning should apply here. Agent Peterson’s con-clusory assertion that the informant had provided reliable and verified information should count for nothing (or next to nothing) in the probable cause calculus. Any other conclusion ignores the requirement that the inferences from the facts supporting probable cause should be drawn not by the officer or the confidential informant, but by a “neutral and detached magistrate.” Aguilar, 378 U.S. at 115, 84 S.Ct. 1509 (internal quotation marks and citation omitted).
This point is not undercut by the majority’s statement that, under applicable Supreme Court precedent, “a proven, reliable informant is entitled to far more credence than an unknown, anonymous tipster.” Ante at 197. I agree that an officer will often have better reason to trust an informant he 'knows than an anonymous voice on the other end of a telephone line. The cases cited by the majority, however, do not speak to the question of whether a magistrate must treat a known confidential informant whose veracity is supported only by bare bones assertions as more credible than an anonymous informant. Neither Florida v. J.L., 529 U.S. 266, 269-70, 120 S.Ct. 1375, 146 L.Ed.2d 254 (2000), nor Adams v. Williams, 407 U.S. 143, 146-47, 92 S.Ct. 1921, 32 L.Ed.2d 612 (1972), has any real bearing on this question because both of these cases dealt only with the distinct question of whether an informant’s tip established the reasonable suspicion required for a police officer to make a Terry stop. When, as in this case, the veracity of a known confidential informant is supported only by the affiant’s concluso-ry assertions, the magistrate can give “far more credence” to a known informant’s tip than to an anonymous tip only by improperly relying on the affiant’s judgments about the informant’s reliability rather than by making an independent evaluation. In short, the difference between a “proven, reliable informant” and an “unknown, anonymous tipster” is only significant from the magistrate’s perspective when the affi-ant informs the magistrate of his grounds for believing the known informant to be reliable. That did not happen here.
Agent Peterson’s assertion in paragraph 5 that his informant had provided reliable and verified information in the past is a bare conclusion that should have been given little or no weight by the magistrate. No reasonable officer would have thought this assertion provided the magistrate with a substantial and independent basis for crediting the informant’s tip. Consequently, Agent Peterson could rely on the May 25 warrant in good faith only if he could reasonably believe that his affidavit’s corroborating evidence provided the magistrate with a substantial basis for concluding that the informant was truthful.
B.
The corroborating information in Agent Peterson’s affidavit appears in paragraphs *2053, 4, and 6. Ante at 194. Together, these paragraphs suggest that Bynum had been convicted of an unspecified felony and that he had been dealing significant quantities of heroin from his apartment at 2234 Wal-cott Place as recently as three and one-half months before Agent Peterson submitted his application for the May 25 search warrant. Whether this degree of corroboration is enough to merit application of the good faith exception is the hardest question in this case. The case law appears to recognize at least two different ways in which corroborating evidence can help to establish an informant’s veracity. As I will' explain below, a first method (discussed in the Supreme Court’s cases on the corroboration of informants’ tips) allows police officers to establish an informant’s veracity by confirming the truth of a portion of the informant’s tip. Courts also appear to recognize a second method of. corroboration. Under this method, any evidence known to the police that tends to establish probable cause also tends to establish the truthfulness of the informant’s tip. In my opinion, the corroborating evidence in Agent Peterson’s affidavit does not adequately support the informant’s veracity in either of these ways. As a result, I would hold that Leon does not apply on these facts because no reasonable officer would have thought that the corroborating evidence in paragraphs 3, 4, and 6 provided the magistrate with a substantial basis for crediting the veracity of the tip.
The Supreme Court has explained that partial corroboration of a tip helps to establish an informant’s veracity because if “an informant is right about some things, he is more probably right about other facts.” Gates, 462 U.S. at 244, 103 S.Ct. 2317 (quoting Spinelli, 393 U.S. at 427, 89 S.Ct. 584 (White, J., concurring)). In other words, the theory is that when police can verify that an informant has spoken truthfully about one thing, they can (in some circumstances) reasonably infer that the informant has also spoken truthfully in his unverified allegations of criminal activity. Here, the only information from the informant that the police were able to corroborate prior to the May 25 search is the claim in paragraph 5 of the affidavit that the informant “ha[d] identified Bynum as a large quantity dealer of heroin.” This claim is substantially corroborated by the evidence in paragraphs 3, 4, and (especially) 6. The question under Leon is whether a reasonable officer would have believed that the informant’s truthfulness in claiming that Bynum was a large quantity heroin dealer provided the magistrate with a substantial basis for crediting the informant’s further claims, set‘out in paragraph 7, that he had been inside Bynum’s apartment within the last 72 hours and had observed Bynum preparing heroin for distribution.
Answering this question requires some standard for deciding when an informant’s truthfulness about one fact makes it reasonable to assume that he has also been truthful about other facts. The Supreme Court’s cases on corroboration indicate that confirmation of the informant’s truthfulness about, just any set of facts will not do. Instead, the Court has asked whether the informant’s knowledge of the facts verified by the police indicates that he was also in a position to know about the criminal activity allegedly being carried out by the subject of the tip. In Florida v. J.L., for example, an anonymous caller told police that a young black male wearing a plaid shirt at a certain bus stop was carrying a gun. The police went to the bus stop and saw a young , black male who was wearing a plaid shirt; one policeman frisked the young man after ordering him to put his hands up on the bus stop. J.L., 529 U.S. at 268, 120 S.Ct. 1375. The Court *206held that the tipster’s truthfulness about the suspect’s physical appearance and location did not establish the reasonable suspicion required for a Terry stop because “it [did] not show that the tipster ha[d] knowledge of concealed criminal activity. The reasonable suspicion here at issue requires that a tip be reliable in its assertion of illegality, not just in its tendency to identify a determinate person.” Id. at 272, 120 S.Ct. 1375. In Alabama v. White, 496 U.S. 325, 110 S.Ct. 2412, 110 L.Ed.2d 301 (1990), police received an anonymous tip that a woman would be leaving a particular apartment at a particular time in a brown Plymouth station wagon and that she would be going to a motel carrying an ounce of cocaine in a brown attache case. Id. at 327, 110 S.Ct. 2412. The police went to the apartment building, saw a car matching the caller’s description, watched a woman as she left the building and entered the car, and followed her on the route to the motel, stopping the car just short of the motel. Id. The Court upheld the stop, emphasizing that the police stopped the car only after verifying “significant aspects” of the informant’s tip. Id. at 332, 110 S.Ct. 2412. In explaining the value of police corroboration of the tip, the Court distinguished between “ ‘easily obtained facts and conditions existing at the time of the tip’ ” and “ ‘future actions of third parties ordinarily not easily predicted.’ ” Id. (quoting Gates, 462 U.S. at 245, 103 S.Ct. 2317). It said that the tip’s predictions of future actions were more important in establishing the credibility of the tip because they “demonstrated inside information — a special familiarity with [the defendant’s] affairs.... Because only a small number of people are generally privy to an individual’s itinerary, it is reasonable for police to believe that a person with access to such information is likely to also have access to rehable information about that individual’s illegal activities.” Id. (emphasis added). We used similar reasoning in Wilhelm. There, the government sought to establish the veracity of an anonymous informant by arguing that the police had verified the informant’s directions to the defendant’s house and that the informant’s descriptions of marijuana transactions were consistent with police knowledge of how marijuana is packaged and sold. We found this corroboration insufficient to establish the informant’s veracity because “[a]lmost anyone can give directions to a particular house without knowing anything of substance about what goes on inside that house, and anyone who occasionally watches the evening news' can make generalizations about what marijuana looks like and how it is packaged and sold.” Wilhelm, 80 F.3d at 121. In short, we reasoned that the corroboration was inadequate because it did not show that the informant was in a position to know anything about the defendant’s criminal activities. Thus, both Wilhelm and the Supreme Court’s cases on corroboration suggest that partial corroboration of an informant’s tip supports the reliability of the tip’s unverified allegations of criminal activity to the extent that the corroboration shows that the informant has inside information about the subject of the tip.
Under this analysis the proper question to ask about Agent Peterson’s affidavit is whether the fact that the informant correctly identified Bynum as a heroin dealer makes it reasonable to credit his claims, set out in paragraph 7 of the agent’s affidavit, that he (the informant) had been inside Bynum’s apartment and that he had personally observed Bynum preparing heroin for distribution. I submit that it does not. A person could easily know Bynum’s general reputation as a heroin dealer without having the sort of relationship with Bynum that would make the person privy to the details of Bynum’s *207drug trafficking activities. Cf. Barber v. State, 43 Md.App. 613, 406 A.2d 668, 678 (1979) (finding police corroboration of informant’s information regarding defendant’s address, telephone number, and pri- or arrest for marijuana possession was inadequate because “many people circulating in the criminal underworld were in possession of all the information verified by the police officer”). In fact, the informant’s knowledge of Bynum’s reputation does not corroborate the unverified aspects of the informant’s tip to any significant degree because it does not show that the informant had ever been inside By-num’s apartment or even that he knew Bynum personally. Accordingly, I conclude that the first method of corroboration does not help the government’s case. A reasonable officer would not have thought the informant’s knowledge that Bynum was a heroin dealer provided the magistrate with a substantial basis for crediting the informant’s claims that he had personally observed Bynum preparing heroin for distribution.
This point, however, does not settle the corroboration issue because our cases appear to recognize a second method of corroboration distinct from that discussed in Gates, White, and J.L. For example, in United States v. Lalor, 996 F.2d 1578, 1581 (4th Cir.1993), we described a suspect’s recent arrest for cocaine possession as corroborating evidence that buttressed the veracity of reports from two confidential informants even though neither informant had told police about the recent arrest. Because the suspect’s recent arrest did not confirm the truth of anything the informants had told police, this aspect of La-lor’s reasoning cannot be based on the theory that an informant who knows certain facts is probably also right about other facts. We apparently reasoned in Lalor that information about the suspect’s recent arrest for cocaine possession supported the veracity of the informants’ claims that the suspect was dealing cocaine simply because it was consistent with those claims and made them more likely to be true. Under this second method of corroboration, any fact that tends to establish the existence of probable cause will also count as corroboration that supports the informant’s veracity because it tends to make the truth of the informant’s incriminating accusations more likely.2' It is this second *208sense of corroboration that the majority apparently relies upon in concluding that the corroboration in this case was far superior to that in Wilhelm. See. ante at 197. In other words, the majority’s argument is that the informant’s claims in paragraph 7 that he had recently observed Bynum preparing heroin for distribution are directly corroborated by the facts that Bynum was a convicted felon and that he lived in an apartment from which police had seized significant evidence of heroin trafficking less than four months earlier. In short, the majority contends that a reasonable officer could have believed that the corroboration provided by Bynum’s prior criminal history gave the magistrate a substantial basis for crediting the informant’s tip. Although I acknowledge that the question is a close one, I disagree.
As the majority points out, ante at 198, courts have consistently observed that a suspect’s prior criminal activity can help to corroborate an informant’s tip. This is not surprising. As a matter of common sense, an informant’s allegation that a convicted drug dealer is selling heroin sounds more credible than an allegation that a local choir director has become a crack dealer. Nevertheless, courts usually rely on a suspect’s prior criminal history as only one among several factors supporting the reliability of the informant’s tip. See, e.g., United States v. Burke, 999 F.2d 596, 598-99 (1st Cir.1998) (holding that an informant’s tip was reliable based on informant’s track record, prior seizure of marijuana plants at defendant’s house, and police investigation confirming unusually high electricity consumption); Lalor, 996 F.2d at 1581 (holding that reliability of informants’ tips was supported by police confirmation of details in the tips and by defendant’s recent arrest for cocaine possession); United States v. Miller, 925 F.2d 695, 699-700 (4th Cir.1991) (holding that a tip’s reliability was supported by officer’s corroboration of informant’s predictions of defendant’s future behavior as well as officer’s knowledge of defendant’s prior criminal activity).3 What is unusual in this case is that the corroboration is based entirely on Bynum’s criminal past. The affidavit points to no evidence aside from the informant’s tip suggesting that Bynum was presently dealing heroin from his apartment. As a result, this case asks us to decide whether it is reasonable to *209credit an informant’s tip solely because the tip is consistent with prior criminal activity by the subject of the tip.
At least in the circumstances of this case, I believe that the implications of a positive answer are unacceptable. As I see it, the veracity of the informant in this case is supported solely by Agent Peterson’s bare bones assertion of the informant’s reliability and by the consistency of the tip with Bynum’s prior criminal history. I have already explained that the bare bones assertions in paragraph 5 of the affidavit do not elevate the credibility of Agent Peterson’s informant above that of an anonymous informant. See supra at 203-04; Brack, 188 F.3d at 755 (explaining that a tip from an informant whose veracity was supported only by conclusory assertions should be treated as though it had been obtained from “an informant of ‘unknown reliability’”). It follows that if a reasonable officer could regard Agent Peterson’s informant as truthful solely on the basis of the corroboration provided by By-num’s criminal history, a reasonable officer could also regard that criminal history as sufficient to establish the truthfulness of a completely anonymous tip. This would mean that once police have evidence that a person has previously engaged in criminal activity in his home, the police can (for at least the next three and one-half months) gain entry to his home whenever any anonymous informant is willing to claim that the person is up to his old tricks.4 A reasonable officer could not believe that such a result can be squared with the Fourth Amendment, Cf. United States v. Harris, 403 U.S. 573, 596, 91 S.Ct. 2075, 29 L.Ed.2d 723 (1971) (Harlan, J., dissenting) (“Surely, it cannot be seriously suggested that, once an individual has been convicted of bootlegging, any anonymous phone caller who states that he has just personally witnessed another illicit sale (up to four years later) by that individual provides federal agents with probable cause to search the suspect’s home.”); Parish v. State, 939 S.W.2d 201, 204 (Tex.Ct.App.1997) (“An anonymous tip, without the observation [by police] of any other activity indicating criminal conduct, does not provide probable cause to search the person’s home or personal effects solely because that individual has a criminal record.”); State v. Mickle, 53 Wash.App. 39, 765 P.2d 331, 334 (1989) (holding that police knowledge that defendant had “grown marijuana in the past” was inadequate corroboration because “it verifie[d] only knowledge of the suspect and his past activities, not that criminal activity [was] presently occurring”).
While I would not go so far as to say that the veracity of an untested informant’s tip can never be corroborated solely by a suspect’s criminal history, the circumstances in which police should be allowed to search a home on this basis should be rare. A contrary holding gives police no incentive to seek independent confirmation of an informant’s claim that a suspect is currently engaged in criminal activity. At the very least, police should be able to rely solely on prior criminal history to establish the veracity of a confidential informant only when that criminal history is quite recent. Here, it would be unreasonable to contend that just because police found evidence of heroin trafficking in Bynum’s apartment during a search on February 10, there was a fair probability that evidence of heroin trafficking would still be *210found there three and one-half months later. It is no more reasonable to contend that just because evidence of heroin trafficking was found in Bynum’s apartment on February 10, an informant who accused Bynum of heroin trafficking three and one-half months later was probably telling the truth. I therefore conclude that Bynum’s prior criminal history did not provide sufficient corroboration of the informant’s veracity to make Agent Peterson’s decision to submit his affidavit objectively reasonable.
In sum, the corroboration in paragraphs 3, 4, and 6 of Agent Peterson’s affidavit was insufficient to merit application of the good faith exception on either theory of corroboration. The problem under the first theory is that even if the police could be said to have confirmed the informant’s claim that Bynum was a large quantity heroin dealer, the informant’s knowledge of that fact has little weight because it does not demonstrate that the informant was in a position to have the kind of inside information attributed to him in paragraph 7. The problem under the second theory is that, in circumstances like this ease, allowing a tip to be corroborated solely by evidence of a suspect’s prior criminal activity will gut the protections of the Fourth Amendment for persons with criminal histories. “Once a crook, always a crook” may be an epigram that is useful at times, but it should not be given the place in our Fourth Amendment law that the majority accords it today.
C.
For the foregoing reasons, I conclude that a reasonable officer would not have submitted Agent Peterson’s affidavit to a magistrate because a reasonable officer would have recognized that the affidavit did not provide the magistrate with a substantial and independent basis for crediting the informant’s claims reported in paragraph 7 of the affidavit. Consequently, Agent Peterson’s affidavit was “so lacking in indicia of probable cause as to render official belief in its existence entirely unreasonable,” and Leon’s good faith exception should not apply. Leon, 468 U.S. at 923, 104 S.Ct. 3405.
II.
Because I disagree with the majority’s conclusion that the information in Agent Peterson’s affidavit was substantial enough to warrant application of the good faith exception, I must deal with a question that the majority did not have to reach: namely, whether an officer’s good faith can be established on the basis of information known to the officer but never presented to a magistrate. Relying on United States v. Weeks, 160 F.3d 1210, 1212-13 (8th Cir.1998), the government argues that even if Agent Peterson’s affidavit was not substantial enough to pass muster under Leon, the good faith exception still applies because Agent Peterson knew, but inadvertently failed to tell the magistrate, that his confidential source was the same informant whose tip had supported the warrant for the earlier, February 10 search of By-num’s apartment.
It is important to set the government’s position in context. Agent Peterson’s actual affidavit said only that the confidential informant had provided reliable information that had been verified. If we credit the government’s claims about what Agent Peterson knew but did not tell the magistrate, Agent Peterson’s affidavit could have said, among other things, that the informant had worked for the Richmond Police Department for eight years, that the informant’s tips had led to multiple convictions in state and federal courts, and (most significantly) that the informant had supplied the tip that established probable *211cause for the earlier search of Bynum’s apartment. See United States v. Bynum, 125 F.Supp.2d 772, 786 (E.D.Va.2000) (recounting information in the affidavit supporting the warrant for the February 10 search). If all of this is true, the affidavit Agent Peterson could have submitted to the magistrate would have established probable cause; but I do not see how Agent Peterson’s failure to inform the magistrate of his basis for trusting his informant helps to establish the agent’s good faith. Indeed, when the gap between what an officer knew and what he told the magistrate is so pronounced, it is hard to believe that the officer inadvertently omitted information about the informant’s reliability in the way that a person might forget to put eggs on his grocery list. There are, in my opinion, only two plausible explanations for Agent Peterson’s decision to tell the magistrate so little about the informant’s reliability when the agent allegedly could have said so much. The first (and perhaps the more likely) possibility is that Agent Peterson omitted all the facts supporting the informant’s veracity because he expected the magistrate simply to ratify his bare conclusion that the informant was reliable. The second is that Agent Peterson did not know the facts the government now claims he knew. Neither possibility supports the government’s argument that Agent Peterson displayed the objective good faith required by Leon.
As the majority observes, ante at 199, courts have split on the difficult question of whether information known to an officer but never presented to a magistrate can be used to establish the officer’s good faith. The government urges us to hold that it can, but I think the Supreme Court’s explanations of the good faith exception in Leon and Malley show that the government is wrong. The problem with the government’s position stems from its basic premise that objective good faith is determined by the reasonableness of the officer’s belief in the existence of probable cause. An officer’s reasonable belief that he has probable cause for a search may be a necessary condition of objective good faith, but it is not a sufficient condition. Leon also requires courts to ask whether the officer had an objectively reasonable belief that his affidavit gave the magistrate a substantial basis for finding probable cause. The point is underscored by Leon’s language describing the third circumstance that bars application of the good faith exception: “Nor would an officer manifest objective good faith in relying on a warrant based on an affidavit so lacking in indicia of probable cause as to render official belief in its existence entirely unreasonable.” Leon, 468 U.S. at 923, 104 S.Ct. 3405 (emphasis added) (internal quotation marks and citation omitted). See also Malley, 475 U.S. at 345, 106 S.Ct. 1092 (stating that courts should determine the objective reasonableness of an officer’s reliance on a warrant by asking “whether a reasonably well-trained officer ... would have known that his affidavit failed to establish probable cause” (emphasis added)). I do not understand how information known to the affiant but not presented to the magistrate can be used to decide whether an affidavit is “so lacking in indicia of probable cause as to render official belief in its existence entirely unreasonable.” Leon and Malley’s emphasis on the officer’s affidavit suggests that an officer has a duty to ask not only whether he knows enough to establish probable cause, but also whether he has given the magistrate at least a substantial basis for finding probable cause.
The same point is implied by Leon’s general principle that the exclusionary rule should apply when “a reasonably well trained officer would have known that the search was illegal despite the magistrate’s *212authorization.” Leon, 468 U.S. at 922 n. 23, 104 S.Ct. 3405. Under Gates, whether a search is illegal depends on whether “the magistrate had a substantial basis for concluding that probable cause existed.” Gates, 462 U.S. at 238, 103 S.Ct. 2317 (internal quotation marks, ellipsis, and citation omitted). Thus, an officer displays objective good faith only when he has a reasonable belief that the magistrate had a substantial basis for finding probable cause. Because the reasonableness of the magistrate’s probable cause determination is solely a function of the information presented to the magistrate, see Whiteley v. Warden, 401 U.S. 560, 565 n. 8, 91 S.Ct. 1031, 28 L.Ed.2d 306 (1971), information not presented to the magistrate cannot be relevant to the question “whether a reasonably well trained officer would have known that the search was illegal despite the magistrate’s authorization.” Leon, 468 U.S. at 922 n. 23, 104 S.Ct. 3405. Here, Agent Peterson’s alleged knowledge about the identity of the informant could not support an objectively reasonable belief that the magistrate had a substantial and independent basis for concluding that there was probable cause for the May 25 search of Bynum’s apartment. It follows that the facts allegedly known to Agent Peterson but omitted from his affidavit are irrelevant to the good faith analysis.
The government’s reading of Leon’s third disqualifying circumstance as covering only cases where the officer lacked an objectively reasonable belief in the existence of probable cause significantly reduces the scope of the third circumstance. In essence, the government suggests that a bare bones affidavit is only bad if the affiant had no objectively reasonable basis for his conclusory assertions. This cannot be correct. The first problem with a bare bones affidavit is not that the affiant’s claims of probable cause might be unfounded, but that the conclusory character of those claims prevents the magistrate from properly performing his constitutional role. See, e.g., Gates, 462 U.S. at 239, 103 S.Ct. 2317 (suggesting that the problem with bare bones affidavits is that they “give[ ] the magistrate virtually no basis at all for making a judgment regarding probable cause”); United States v. Barrington, 806 F.2d 529, 532 (5th Cir.1986) (explaining that an officer could not reasonably rely on a bare bones affidavit because “he had no good faith reason to believe the magistrate had made a probable cause determination”). The government fails to recognize that an officer’s decision to submit a bare bones affidavit is objectively unreasonable simply because it asks the magistrate to ratify the officer’s bare conclusions. Regardless of the officer’s grounds for judging the informant to be truthful, the decision not to share those grounds with the magistrate should not be protected by the good faith exception because it is not “objectively reasonable law enforcement activity.” Wilhelm, 80 F.3d at 123 (internal quotation marks omitted).
In sum, the government cannot establish an officer’s objective good faith under Leon by producing evidence of facts known to the officer but not disclosed to the magistrate. This is because Leon requires that the officer be able to entertain a reasonable belief that the magistrate had a substantial basis for finding probable cause. Whether that belief is reasonable can depend only upon the facts presented to the magistrate. Thus, even in the most benign of circumstances (for example, when an officer has inadvertently omitted from his affidavit a crucial detail that would have established the relationship between the suspected criminal activity and the place to be searched), what the officer knew but did not tell the magistrate is irrelevant. See People v. Deitchman, 695 P.2d 1146, 1166 (Colo.1985) (Quinn, J., concurring) (explaining that to admit evidence on the ground that the affiant had inadver*213tently omitted from his affidavit evidence that the defendant lived at the address to be searched would substitute “subjective good faith” for Leon’s objective good faith standard). Here, the circumstances are less than benign. If Agent Peterson actually knew all the facts supporting the informant’s reliability that the government claims he knew, his failure to include any of these facts in his affidavit signals a disturbing level of confidence that the magistrate would approve anything that was put in front of him. It is difficult to believe that any officer who understood the warrant process to require independent testing of evidence by a neutral and detached judicial officer would simply forget to include this kind of information. Accordingly, I would hold that Agent Peterson’s alleged knowledge about the identity of the informant cannot be used to put flesh on his bare bones affidavit.
III.
In dissenting from Leon nearly twenty years ago, Justice Brennan predicted that the long run effect of that decision would be “to undermine the integrity of the warrant process.” Leon, 468 U.S. at 958, 104 S.Ct. 3405 (Brennan, J., dissenting). The facts of this case suggest that Justice Brennan’s fears were well founded. If the government’s unverified claims about the identity of Agent Peterson’s confidential informant are true, the agent could have submitted an affidavit that would have conclusively established probable cause for the search of Bynum’s apartment under even the most exacting standards. Instead, he submitted an affidavit containing only bare bones, conclusory assertions of the informant’s reliability. Agent Peterson also failed to provide the magistrate with any corroborating evidence that could establish the informant’s reliability as a source of information about Bynum’s criminal activities. That Agent Peterson thought his affidavit worthy of submission to a magistrate suggests that he viewed the warrant process as no more than a mere formality. That a warrant was issued on the basis of the affidavit suggests, unfortunately, that he may have been right. That the evidence seized under that invalid warrant will now be used against the defendants under Leon tells police officers in no uncertain terms that “if they can secure a warrant ... all police conduct pursuant to that warrant will be protected from further judicial review.” Id. at 957, 104 S.Ct. 3405 (Brennan, J., dissenting). I respectfully dissent.
. I deal briefly with one point raised by the majority that was not pressed by the government. The majority suggests that even though Agent Peterson failed to “expressly inform the magistrate judge that the confidential source was the same source who provided information for the February 10 search,” ante at 196, Peterson reasonably relied on the search warrant in part because the magistrate "could reasonably have inferred a link between the confidential source [referred to in paragraphs 5 and 7 of Agent Peterson’s affidavit] and the February search [described in paragraph 6 of the affidavit],” id. I agree with the majority that the good faith exception would apply in this case if the affidavit fairly implied that the informant mentioned in paragraphs 5 and 7 provided the information that supported the warrant for the February 10 search. I cannot agree, however, that a magistrate could reasonably draw the inference suggested by the majority. Because the link between Agent Peterson’s confidential informant and the February 10 search would provide such powerful evidence of the informant’s veracity, a reasonable magistrate would expect the affidavit to set out this information explicitly. See United States v. Bynum, 125 F.Supp.2d 772, 793 (E.D.Va.2000) (stating that the absence of any linkage in the affidavit between the confidential source and the February 10 search was significant because the affiant would have "provided this obvious indicia of the informant's reliability and veracity, if it existed”). Paragraphs 5 and 7 of Agent Peterson's affidavit do refer explicitly to information provided by the informant, see ante at 194, but paragraph 6 (dealing with the February 10 search) says nothing about the informant or about how the earlier search warrant was obtained. Under these circumstances, the only reasonable inference for a magistrate to draw would be that Agent Peterson’s informant had nothing to do with the February 10 search.
. It might be questioned whether this second method of corroboration is consistent with the reasoning of the Supreme Court cases on corroboration of informants’ tips. Those cases explain that confirming one aspect of an informant's tip helps to demonstrate that the informant was both “honest” and “well informed.” White, 496 U.S. at 332, 110 S.Ct. 2412. See also 2 LaFave, supra, § 3.3(f) at 167 (" 'When independent police observations have verified part of the story told by an informant, that corroboration lends credence to the remaining unverified portion of the story by demonstrating that the informant has, to the extent tested, spoken truly.... Present good performance shows him to be probably 'credible' just as surely as does past good performance.' ”) (quoting Stanley v. State, 19 Md.App. 507, 313 A.2d 847, 860-61 (Md.Ct.Spec.App.1974)). In contrast, the theory of corroboration recognized in Lalor tells the magistrate nothing whatsoever about the honesty of the individual informant because any tip (even an anonymous phone call made to the police by a pathological liar) will be corroborated to the extent that the police have information that tends to establish probable cause. Nevertheless, the second method of corroboration is routinely employed by courts and seems justified because there is an obvious sense in which an informant’s allegation of criminal activity is far more likely to be true when the police have other information independently suggesting that the subject of the tip is engaged in criminal activity. Cf. United States v. Miller, 925 F.2d 695, 699 (4th Cir.1991) (emphasizing that neither Supreme Court nor Fourth Circuit precedents "create! ] a requirement that police officers acting on an informant’s tip must corroborate that tip in some specific way such as conducting an independent investigation”).
. A possible exception is United States v. Taylor, 985 F.2d 3, 6 (1st Cir.1993), where the court held that an affidavit recounting an informant’s first hand observation that the defendant was growing marijuana plants on her property was sufficient to establish probable cause. In Taylor the affidavit made only the conclusory assertion that the informant "ha[d] provided reliable information ... in the past,” id. at 5, and the tip was corroborated mainly by evidence in police records that, nearly five years earlier, the defendant had admitted to cultivating marijuana on the same property and had pled guilty to two counts of marijuana trafficking, id. at 6. The Taylor court also emphasized, however, that the magistrate was entitled to rely on the affiant's judgment that the informant had accurately described what a marijuana growing operation looks like. Id. Thus, even Taylor did not rely solely on past criminal activity to corroborate the informant’s tip. Nevertheless, I acknowledge that Taylor offers strong support for the majority’s position because it finds an adequate basis for probable cause in an affidavit that is arguably weaker than Agent Peterson's. We are not bound to follow Taylor, of course, and I believe that case was wrongly decided. Evidence of criminal activity nearly five years in the past should not count as sufficient corroboration to establish the truthfulness of a tip supported only by a bare, conclusory assertion of the informant's reliability. Nor should the informant’s realistic description of a marijuana growing operation be enough to change the result. Cf. Wilhelm, 80 F.3d at 121 (observing that "anyone who occasionally watches the evening news can malte generalizations about what marijuana looks like and how it is packaged and sold”).
. I trust the majority would agree that there must be some point at which a suspect’s prior criminal activity is simply too remote in time to justify an inference that an unproven informant’s allegation of present criminal activity is trustworthy. Obviously, the majority does not believe that point has been reached in this case.