Opinion for the court filed by Circuit Judge GINSBURG, in which Chief Judge McGOWAN, and Circuit Judges WRIGHT, ROBINSON, WALD, MIKVA, and EDWARDS concur.
Separate opinion, dissenting in part, filed by Circuit Judge TAMM, in which Circuit Judge ROBB concurs.
Dissenting opinion filed by Circuit Judge MacKINNON.
Dissenting opinion filed by Circuit Judge ROBB.
Dissenting opinion filed by Circuit Judge WILKEY.
GINSBURG, Circuit Judge:In Arkansas v. Sanders, 442 U.S. 753, 99 S.Ct. 2586, 61 L.Ed.2d 235 (1979), the Supreme Court settled the question whether police officers, in the absence of exigent circumstances, are required to obtain a warrant before opening and searching luggage, large or small, locked or unlocked, taken from an automobile properly stopped and searched’ for contraband. The Court held that absent a warrant, such searches violate the Fourth Amendment, even when the luggage has been lawfully seized. The case before us raises the question whether Sanders establishes only a “luggage rule” or whether the reasoning of that decision extends as well to other containers used to carry personal belongings and effects, containers smaller, less solid, or less durable than those on sale in a luggage shop.1
*1161The two items initially in contention in this case were a closed but untaped brown paper bag and, lying alongside it in the trunk of defendant Ross’s car, a zippered red leather pouch. The Government successfully opposed a motion to suppress the evidence found in both containers, heroin in the paper bag, cash in the leather pouch. Although it earlier argued that both bag and pouch were subject to warrantless search,2 the Government, despite its success in the trial court, now concedes that the pouch is covered by the rule in Sanders.3 It continues to urge, however, that a paper bag does not merit classification as a protected repository for personal effects.
We conclude that Sanders did not establish a “worthy container” rule encompassing bags of leather but not of paper. Rather, it appears to us that Sanders reaffirmed the Supreme Court’s longstanding position regarding the centrality of the warrant requirement to Fourth Amendment administration: absent a “specifically established and well-delineated” exception, a warrant-less search is per se impermissible. Katz v. United States, 389 U.S. 347, 357, 88 S.Ct. 507, 514, 19 L.Ed.2d 576 (1967); Coolidge v. New Hampshire, 403 U.S. 443, 454-55, 91 S.Ct. 2022, 2031-32, 29 L.Ed.2d 564 (1971); Schneckloth v. Bustamonte, 412 U.S. 218, 219, 93 S.Ct. 2041, 2043, 36 L.Ed.2d 854 (1973).
No specific, well-delineated exception called to our attention permits the police to dispense with a warrant to open and search “unworthy” containers. Moreover, we believe that a rule under which the validity of a warrantless search would turn on judgments about the durability of a container would impose an unreasonable and unmanageable burden on police and courts.4 For these reasons, and because the Fourth Amendment protects all persons, not just those with the resources or fastidiousness to place their effects in containers that deci-sionmakers would rank in the luggage line, we hold that the Fourth Amendment warrant requirement forbids the warrantless opening of a closed, opaque paper bag to the same extent that it forbids the warrant-less opening of a small unlocked suitcase or a zippered leather pouch.
Part I of this opinion states the facts that give rise to this controversy; Part II deals with threshold issues the Government has raised — belated challenges to the retroactivity of Sanders and to Ross’s standing to seek suppression of the evidence found in the paper bag; Part III concerns the scope of Sanders and the application of its holding and reasoning to this case.
I.
On November 27,1978, Detective Charles Marcum of the Washington, D.C., Metropol*1162itan Police Department received a telephone call from an informant who on prior occasions had provided reliable information about narcotics trafficking. The informant told Marcum that he had observed a man known as “Bandit” selling narcotics in front of 439 Ridge Street, N.W.; he furnished a detailed description of “Bandit” and reported that the drugs were in the trunk of Bandit’s automobile, a maroon two-door Chevrolet Malibu with District of Columbia license plates.
Detective Marcum, Detective David Cas-sidy, and Sergeant Raymon Gonzales drove to Ridge Street where they observed a car matching the informant’s description. A radio check revealed that the car was registered to an Albert Ross, Jr., whose nickname was “Bandit.” The police officers passed through the area twice, then spotted Ross driving the car. After stopping the vehicle and identifying themselves, the police asked Ross to step out of his car. Ross matched the description the informant had given Marcum. As Marcum conducted a body search, Gonzales observed a round of ammunition on the car’s front seat. Gonzales retrieved the round, searched the inside of the car for weapons, and found a pistol in the glove compartment. Marcum arrested Ross and handcuffed him; Detective Cassidy then unlocked and searched the car’s trunk. He found in it side by side a closed but unsealed brown paper sack about the size of a lunch bag and a zippered red leather pouch. Cassidy immediately opened the paper bag and discovered inside a quantity of glassine envelopes containing a white powder. Leaving the bag and the pouch in the trunk, the officers drove Ross’s car to police headquarters. At the station, Cassidy reopened the paper bag, determined that it contained thirty glassine envelopes, and sent the envelopes to the police laboratory for analysis; the laboratory later reported that the envelopes contained heroin. Cassidy also opened the leather pouch and found inside $3200 in currency. At no point in the episode did the officers seek a search warrant.
On December 19, 1978, a federal grand jury in the District of Columbia indicted Ross for possession of heroin, possession of heroin with intent to distribute, carrying a pistol without a license, and possessing a firearm after a felony conviction. Ross moved to suppress the evidence obtained from the search of the paper bag and the leather pouch. After a hearing, the district judge denied the motion. A jury trial followed and, on March 21, 1979, Ross was convicted of possession of narcotics with intent to distribute, in violation of 21 U.S.C. § 841(a).
II.
(A)
Although the Government did not raise the point before the panel, it argues here that Arkansas v. Sanders should not apply retroactively. In United States v. Peltier, 422 U.S. 531, 535, 95 S.Ct. 2313, 2316, 45 L.Ed.2d 374 (1975), the Supreme ' Court reiterated that decisions expanding the scope of the exclusionary rule should have prospective effect only. A court should not apply a decision retroactively if the “law enforcement officials [yvho conducted the search] reasonably believed in good faith that their conduct was in accordance with the law” in effect at the time of the search. Id. at 538, 95 S.Ct. at 2317 (emphasis deleted). If, however, a decision does not expand the exclusionary rule, but merely restates and applies doctrine already in place, then law enforcement officers must be charged with knowledge of that doctrine before the explanative decision issues. The Supreme Court in Sanders indicated that no new constitutional principle was at stake. On the contrary, the Court styled its opinion as a recapitulation of the theme exposed in United States v. Chadwick, 433 U.S. 1, 97 S.Ct. 2476, 53 L.Ed.2d 538 (1977). Therefore we cannot seek refuge in Peltier to justify a declaration that Sanders commands only prospective adherence.
Justice Powell’s opinion for the Court in Sanders signals that the decision, affirming the judgment of the Supreme Court of Arkansas, breaks no new ground. The open*1163ing paragraph announces a purpose to elaborate, not to alter, existing doctrine: “We took this case ... to resolve some apparent misunderstanding as to the application of our decision in United States v. Chadwick ....” 442 U.S. at 754, 99 S.Ct. at 2588. Summing up in Sanders, Justice Powell declared that the Court found “no justification for the extension of [Carroll v. United States, 267 U.S. 132, 45 S.Ct. 280, 69 L.Ed. 543 (1925)] and its progeny to the warrant-less search of one’s personal luggage merely because it was located in an automobile lawfully stopped by the police.” Id. at 765, 99 S.Ct. at 2594. Justice Powell, therefore, indicated that a majority of the Court believed that a decision contrary to the one reached in Sanders, rather than the one. there made, would have altered prior law.5
Between Chadwick and Sanders, moreover, at least four courts held that Chadwick rendered unlawful the warrantless search of luggage seized from a car.6 These rulings contrast with pre-Chadwick decisions, which held consistently that no warrant was required to search luggage seized from a car.7 The shift in the trend of lower court decisions after Chadwick thus anticipated the Supreme Court’s signification in Sanders that Chadwick, not Sanders, was the path-marking decision.
For these reasons we conclude that Arkansas v. Sanders did not augment, but simply explained and applied, doctrine welded in place since Chadwick — doctrine that Detective Cassidy knew or should have known when he searched the containers found in the trunk of Ross’s car. We therefore reject the Government’s belated argument and join the numerous courts that have held Sanders retroactively applicable at least to searches conducted after Chadwick8 United States v. Dien, 609 F.2d 1038 (2d Cir. 1979), adhered to on petition for rehearing, 615 F.2d 10 (2d Cir. 1980); United States v. Medina-Verdugo, 637 F.2d 649 (9th Cir. 1980); United States v. MacKay, 606 F.2d 264 (9th Cir. 1979); State v. White, 94 N.M. 687, 615 P.2d 1004, 1006 (Ct.App. 1980) (argument that Sanders does not apply retroactively is “spurious”); Abell v. Commonwealth, 221 Va. 607, 272 S.E.2d 204 (1980); cf. United States v. Bulgier, 618 F.2d 472 (7th Cir.) (assuming retroactive application of Sanders and upholding search), cert. denied, 449 U.S. 843, 101 S.Ct. 125, 66 L.Ed.2d 51 (1980). But cf. State v. Hatami, No. A-1567-77 (N.J.Super. Ct.App.Div. Nov. 21,1979) (per curiam) (unpublished opinion) (refusing to apply Sanders retroactively to a pre-Chadwick search), certification denied, 85 N.J. 471, 427 A.2d 567, cert. denied, 449 U.S. 1035, 101 S.Ct. 610, 66 L.Ed.2d 496 (1980).
We note, finally, that doubt some courts and commentators expressed, in the wake of Chadwick, about whether the police needed a warrant to search closed containers seized from a car, cannot justify Detec*1164tive Cassidy’s failure to obtain a search warrant before opening the paper sack and leather pouch found in Ross’s car. The Supreme Court has firmly held that “searches conducted outside the judicial process, without prior approval by judge or magistrate, are per se unreasonable under the Fourth Amendment — subject only to a few specifically established and well-delineated exceptions.” Katz v. United States, 389 U.S. 347, 357, 88 S.Ct. 507, 514, 19 L.Ed.2d 576 (1967). That declaration indicates doubts police officers may entertain are to be resolved in favor of, not against, the main rule that a warrant precede a search. We cannot invert the Supreme Court’s instructions by sanctioning police conduct of warrantless searches, subject only to the courts’ prior express mandate that they obtain a warrant. Rather, we are required to adhere to the Court’s command that the police obtain a warrant unless their search falls within one of the express and narrowly drawn exceptions to the warrant requirement. Read against this background, the Court’s statement in Peltier, that a retroactivity ruling is impermissible when a police officer believes “in good faith” that his conduct is “in accordance with the law,” 422 U.S. at 538, 95 S.Ct. at 2318, must mean that Detective Cassidy had to believe, in good faith, that his conduct fell within one of the few, jealously drawn exceptions to the warrant requirement. In sum, if Detective Cassidy had doubts about the meaning of Chadwick, he should have followed the presumption laid down in numerous Supreme Court decisions and obtained a warrant.9 His doubts, even af-fer Peltier, should not have been resolved against the warrant requirement.10
(B)
A second preliminary issue not previously raised by the Government concerns Ross’s “standing.” In contrast to its position regarding Sanders, the Government here champions retroactivity, specifically, the retroactivity of the Supreme Court’s decision in United States v. Salvucci, 448 U.S. 83, 100 S.Ct. 2547, 65 L.Ed.2d 619 (1980).
When Ross moved to suppress the evidence obtained from the search of the pouch and bag, and when his case was tried, the “automatic standing” rule of Jones v. United States, 362 U.S. 257, 80 S.Ct. 725, 4 L.Ed.2d 697 (1960), governed lower courts. Under Jones, a defendant charged with a crime of possession was entitled to claim “automatic standing” to challenge the legality of a search that produced evidence against him. Ross therefore did not testify at the suppression hearing and the Government raised no objection to his silence.
The Government’s evidence at trial was substantially the same as the evidence it presented at the hearing on the motion to suppress. The police described the circumstances surrounding the arrest of Ross, including the attendant searches of the pouch and bag. Having lost the suppression motion, Ross defended at trial by denying, knowing anything about packets of narcotics in a paper bag in the trunk of his car.
*1165After the initial hearing and decision of this appeal11 the Supreme Court overruled Jones v. United States. In United States v. Salvucci, 448 U.S. 83, 100 S.Ct. 2547, 65 L.Ed.2d 619 (1980), the Court held that defendants charged with crimes of possession may claim the benefits of the exclusionary rule only if they first establish that their own Fourth Amendment rights have been violated. Relying on Salvucci, the Government now asserts for the first time that Ross, by his tactic at trial, coupled with his silence at the suppression hearing, forfeited any claim that his own Fourth Amendment rights were violated. Ross’s professed igno- ■ ranee of the narcotics-filled paper bag in his trial testimony, the Government argues, pinions him. He cannot now be heard to claim that he secreted the bag in the trunk, hence he cannot satisfy the Salvucci requirement.
But the Supreme Court in Salvucci did not rule that Jones was overruled retrospectively. In fact, the Court noted that Jones bound the lower courts until it said otherwise. 448 U.S. at 85,100 S.Ct. at 2550. In contrast to Sanders, which was a confirming and clarifying decision, Salvucci was a forthright overruling of prior High Court precedent.12
In Salvucci itself the Government had challenged the defendant’s “standing” from the start. No such challenge was raised in the case before us. We decline to transform this case into the “Catch-22” the Government proposes. Had the Government raised a standing question at the suppression hearing, Ross and his counsel would have been alerted to the risk of Ross’s remaining silent and failing to assert that both pouch and bag were items under his exclusive possession and control until he encountered the police. More significant in view of the context in which the case comes to us, had the district court granted the suppression motion, as we believe it should have, there would have been no trial and no testimony from Ross denying knowledge of the bag found in his trunk.
The unfairness of now saddling Ross with the rule in Salvucci rather than the one in Jones is evident.13 Ross’s positions, his silence at the suppression hearing and his testimony at trial, should not be judged by a rule that did not exist until after his hand had been fully played. We therefore hold that Jones, not Salvucci, provides the “standing” rule that governs this case.
Moreover, even if Ross’s standing were now to.be determined under the Salvucci test, we could not accept the Government’s position that his trial tactic, denying knowledge of the bag, strips him of Fourth Amendment protection. The jury found Ross guilty beyond a reasonable doubt. To make that determination the jury necessarily concluded that the narcotics-filled bag belonged to Ross. To reach that conclusion, the jury had to reject Ross’s attempt at trial to suggest that someone else might have placed the bag in the trunk of the car. The jury’s verdict, we believe, resolves any issue whether the bag belonged to Ross — it did. In view of the jury determination, the Government cannot argue sensibly that the bag was Ross’s for purposes of the conviction, but someone else’s for Fourth Amendment purposes.
It may be, however, that in emphasizing Ross’s trial testimony, the Government does not seriously challenge Ross’s exclusive control and possession of the narcotics-filled *1166bag prior to his apprehension by the police. Rather, the Government may be asserting that standing requires an expectation of privacy, which Ross’s trial testimony, “There wasn’t supposed to be no paper bag in [the car trunk],” defeats. But given the jury verdict, we must take it to be fact that there was supposed to be a paper bag in the trunk and Ross put it there. The Government now concedes that Ross had an adequate expectation of privacy in the currency-filled pouch. We find it difficult to comprehend why that same expectation would not attend a contraband-filled closed container Ross secreted in the locked trunk alongside the pouch.14
III.
Turning to the application of Supreme Court precedent in point, most immediately, Arkansas v. Sanders, we find only two arguable bases for the warrantless searches of Ross’s pouch and bag. First, in Sanders, as in Chadwick, police suspicion related to the containers, not to the vehicles in which they were placed. In this case, the informant told the police that Ross had narcotics in the trunk of his car. No specific container was identified. Conceivably, we could distinguish those cases in which the police focus their suspicion on the container from those in which the vehicle or an integral part of it attracts police attention.15 Second, Chadwick and Sanders might be cubbyholed as luggage cases, decisions applying the Fourth Amendment warrant requirement to effects placed in durable containers, with no carryover to effects put in less stable packets.
As we explain further below, we believe the first of these two bases is precluded by the Court’s statement of the “misunderstanding” it sought to resolve in Sanders. Moreover, we note that the Government does not urge that we distinguish searches based on police suspicion directed to a vehicle or an integral part of it, from those in which suspicion focuses on a particular container carried in the vehicle. For such a distinction, applied to this case, would render the pouch as vulnerable to warrantless search as the bag, and the Government now concedes that under the Sanders decision, a warrant is prerequisite to exposing the contents of the pouch.
The second basis is pressed by the Government and has attracted several courts.16 But just as the Supreme Court was unable to tie to the Fourth Amendment warrant requirement any “established, well-delineated” exception for luggage, we are unable to perceive such an exception for packets less resistant than luggage to hard wear and frequent use.
We discuss below in more detail each of the two possible bases for reading out of this case the Fourth Amendment warrant requirement.
(A)
In Sanders, local police received a tip that a passenger on a designated flight due in at the municipal airport would be carrying a small green suitcase containing marijuana. The police observed the passenger’s departure from the terminal, green suitcase in tow, and the placement of the suitcase in the trunk of a taxicab. The taxi drove off *1167and was stopped by pursuing officers several blocks from the terminal. At police request, the taxi driver opened the trunk. The police then seized the green suitcase, which was unlocked, opened it, and found inside ten marijuana packets. The Supreme Court affirmed the decision of the Supreme Court of Arkansas holding that the trial court should have suppressed the marijuana because it was obtained through an unlawful search of the suitcase.
The Court granted certiorari in Sanders to resolve “some apparent misunderstanding” among lower courts about the application of United States v. Chadwick, 433 U.S. 1, 97 S.Ct. 2476, 53 L.Ed.2d 538 (1977).17 Chadwick held that a footlocker placed in the trunk of an automobile parked at a curb could lawfully be taken into police custody, because the police had probable cause to believe it contained contraband, but could not lawfully be searched without a warrant. To illustrate the post-Chadwick misunderstanding among lower courts, the Supreme Court cited United States v. Finnegan, 568 F.2d 637, 641-42 (9th Cir. 1977), and United States v. Stevie, 582 F.2d 1175, 1178-79 (8th Cir. 1978) (en banc), cert. denied, 443 U.S. 911, 99 S.Ct. 3102, 61 L.Ed.2d 876 (1979).
In Finnegan, the car, not a particular container in it, originally attracted police attention.18 In Stevie, the police suspicion related to baggage placed in a car, not to the vehicle in which the luggage was carried.19 The Ninth Circuit panel in Finnegan reasoned that Chadwick was inapplicable when car rather than container was the object of suspicion. Instead, the Finnegan court held, Chambers v. Maroney, 399 U.S. 42, 90 S.Ct. 1975, 26 L.Ed.2d 419 (1970), controlled. Chambers upheld the “automobile exception” to the warrant requirement; it sustained the constitutionality of a war-rantless search of a vehicle on a street or highway when the police have probable cause to believe the vehicle contains contraband or evidence of crime. The Finnegan court pointed out that if Chadwick, not Chambers, applied, then police could search without a warrant for a brick of marijuana lying inside a car trunk, but not for one inside a suitcase in the trunk. 568 F.2d at 641. Stevie, on the other hand, held Chadwick dispositive; in so ruling, the Eighth Circuit stated explicitly that it disagreed with the reasoning of the Ninth Circuit panel in Finnegan. 582 F.2d at 1179.
The Supreme Court identified Finnegan and Stevie as inconsistent decisions and it sought in Sanders to resolve the inconsistency. It seems apparent, therefore, that the Sanders majority did not believe the compatibility of the search with the Fourth Amendment should turn on whether police suspicion related to the car (as in Finnegan ) or to the container (as in Stevie). We cannot treat the Finnegan-Stevie citations in Sanders as idle or haphazard.20 We must accept the clear implication of Sanders: Stevie was correctly decided; Finnegan incorrectly applied Chambers rather than Chadwick.
In Sanders, police suspicion related to the suitcase itself. In the case before us, the car trunk, not any identified container in it, was suspected of carrying contraband. But the Supreme Court’s disapproval of Finnegan controls our analysis. Where a contain*1168er legitimately seized from a car trunk is searched without a warrant, Sanders precludes different outcomes when the container is suspected of housing contraband, and when the car itself is the object of suspicion.21 We therefore conclude that, in this case, if a small suitcase had been removed from the trunk of Ross’s car, and thereafter searched without obtaining a warrant, Sanders would mandate suppression of incriminating evidence found in the suitcase. The Government does not contest that conclusion, nor does it contest that it applies as well to the evidence seized in this case from the leather pouch. Supplemental Brief for Appellee at 7. Accordingly, the sole question we must determine is whether the Fourth Amendment protection cloaking an unlocked small suitcase and a zippered leather pouch stops short of a closed but unsealed paper bag.
(B)
Before addressing whether Sanders envisions and the Fourth Amendment tolerates a warrant rule covering small suitcases and pouches but not paper bags, we set out facets of this case the parties do not seriously dispute. Based on the tip the police received22 Ross’s car was properly stopped and searched, and the pouch and bag were properly seized. However, no “special exigencies”23 justified opening the pouch or the bag without a warrant: both containers were securely removed from Ross’s reach at the time of the seizure; the police entertained no belief that the containers or their contents endangered their personal safety; with the pouch and bag in police possession there was no risk that evidence would be lost or destroyed before a warrant could be obtained. Cf. People v. Belton, 50 N.Y.2d 447, 407 N.E.2d 420, 429 N.Y.S.2d 574 (1980) (warrantless search of jacket pockets may not be upheld as search incident to arrest once object is within the exclusive control of the police), cert. granted, 449 U.S. 1109, 101 S.Ct. 917, 66 L.Ed.2d 838 (1981).
Also beyond serious question is the coherent position the Supreme Court has elaborated with respect to the warrant requirement. The reasonableness of a search in light of the surrounding circumstances does not obviate the need for a warrant. Sanders, 442 U.S. at 758, 99 S.Ct. at 2590. On the contrary, the warrant requirement affords protection separate and distinct from the protection against unreasonable searches. See generally Amsterdam, Perspectives on the Fourth Amendment, 58 Minn.L.Rev. 349, 358-60, 374, 395 (1974). Whether or not the search would be “reasonable,” the warrant requirement operates “as a matter of course.” Sanders, 442 U.S. at 758, 99 S.Ct. at 2590 (quoting from Coolidge v. New Hampshire, 403 U.S. at 481, 91 S.Ct. at 2046):
In the ordinary case ... a search of private property must be both reasonable and pursuant to a properly issued search *1169warrant. The mere reasonableness of a search, assessed in the light of the surrounding circumstances, is not a substitute for the judicial warrant required under the Fourth Amendment. ...
“The warrant requirement has been a valued part of our constitutional law for decades, and it has determined the result in scores and scores of cases in courts all over this country. It is not an inconvenience to be somehow ‘weighed’ against the claims of police efficiency. It is, or should be, an important working part of our machinery of government, operating as a matter of course to check the ‘well-intentioned but mistakenly overzealous executive officers’ who are a part of any system of law enforcement.”
Sanders reiterated that exceptions to the warrant requirement are few in number, jealously guarded, and carefully delineated. 442 U.S. at 759-60,99 S.Ct. at 2590-91. We discern no established, well-drawn exception covering the opening of pouch or bag in this case. True, precedent fully supports stopping Ross’s vehicle and seizing the pouch and bag. But the “automobile exception” 24 invoked to justify stopping the car and placing items found in it under police control cannot be stretched to encompass the warrantless openings.25 The automobile exception rests on the inherent mobility of motor vehicles and the “severe,” sometimes “impossible” burdens police departments would encounter were they required to place at every officer’s beck and call “the people and equipment necessary to transport impounded automobiles to some central location until warrants could be secured.” Sanders, 442 U.S. at 761, 765-66 n.14, 99 S.Ct. at 2594-95 n.14. However, the pouch and bag with which we deal were immobilized by police seizure; it was hardly burdensome to carry them unopened to a magistrate. In short, with respect to inspecting the contents of pouch and bag, the police in this case were saddled with no burden other than the inconvenience obtaining a warrant imposes in any ease.
Nor is it arguable that the search of pouch or bag was permissible as incident to an arrest. At no time after the car was stopped were the pouch and bag within Ross’s immediate control. There was not the slightest danger that Ross or anyone other than the police would remove the contents of the containers before a warrant could be obtained. A delay in opening the pouch and bag pending appearance before a magistrate would not have jeopardized the safety of the police or the public. See Sanders, 442 U.S. at 763-64 n.ll, 99 S.Ct. at 2593 n.ll; cf. Amsterdam, supra, 58 Minn. L.Rev. at 412-14.26
Since no exception to the warrant requirement thus far delineated by the Supreme Court covers this case, the prosecution asks, in essence, that we delineate a new one. On the facts before us, it appears certain that the police could have obtained a warrant had they applied to a magistrate before opening the seized items. But surely an exception to the warrant requirement cannot rest on a post hoc judgment that a warrant would have been granted if one *1170had been requested. See Sanders, 442 U.S. at 764 n.12, 99 S.Ct. at 2593 n.12 (reasonableness of search, coupled with inconvenience of approaching a magistrate, does not justify dispensing with a warrant). Rather, the argument appears to be that some containers are fair game once they are seized because they are too small, too insecure, or too cheaply made to burden the time of a magistrate.
The fine distinctions into which the police and the courts would be drawn were we to adopt an “unworthy container” rule are apparent.27 Size could not be the dividing line, nor does the Government contend otherwise given its concession that the leather pouch is encompassed by Sanders. A priceless bequest, great grandmother’s diary, for example, could be carried in a sack far smaller than one accommodating jogging suit and sneakers. And if quality of material is what counts, on what side of the line would one place the variety of parcels people carry? Are police to distinguish cotton purse from silk; felt, vinyl, canvas, tinfoil, cardboard, or paper containers from leather; sacks closed by folding a flap from those closed with zippers, drawstrings, buttons, snaps, velcro fastenings, or strips of adhesive tape? Would a Tiffany shopping bag rank with one from the local supermarket?28
The point need not be labored further. Not only would an “unworthy container” rule fail to supply an “easily understood and administered” guide for the police,29 it would suffer from infirmities more critical than administrative infeasibility. It would snare those without the means or the sophistication to use worthy containers.30 And, most importantly, it would destroy the coherence of a well-established, clear, eminently manageable rule that, absent special necessity, a search must rest upon a search warrant.
Sanders, it seems to us, did not leave the matter in large doubt. The Court there indicated when the nature of the container would justify immediate search: “[S]ome containers (for example a kit of burglar tools or a gun case) by their very nature cannot support any reasonable expectation of privacy because their contents can be inferred from their outward appearance. Similarly, in some cases, the contents of a package will be open to ‘plain view,’ thereby obviating the need for a warrant.” 442 U.S. at 765 n.13, 99 S.Ct. at 2593 n.13. Those guides, we think, are comprehensible, administrable, and consistent with the Supreme Court’s stress on the centrality of the warrant requirement to Fourth Amendment enforcement.
Ordinarily, one cannot infer from the density, shape, or size of a leather pouch or opaque paper bag what is inside,31 and this *1171case presents no exception. The Government does not assert that the very appearance or feel of the paper bag seized from Ross’s car trunk suggested its contents.32 Nor does the Government argue that the contents of the bag were in “plain view” or that Ross willingly displayed what his sacks carried.33 The means that Ross employed to store the contents of pouch and bag, it seems to us, were calculated to secure the privacy of his possessions against intrusion by members of the public.34
In summary, we cannot sanction the war-rantless searches in this case without distorting the reasoning and diminishing the holding in Sanders. Nor can we distinguish between pouch and bag in a manner that makes theoretical or practical sense. We therefore conclude that “[w]here — as in the present case — the police, without endangering themselves or risking loss of the evidence,” lawfully have stopped a car, detained any person in it suspected of criminal activity, and secured parcels found in the car, they must delay search of the parcels “until after judicial approval has been obtained. In this way, constitutional rights of suspects to prior judicial review of searches will be fully protected.” Sanders, 442 U.S. at 766, 99 S.Ct. at 2594.
IV.
Because Ross’s conviction rested on evidence the police obtained through unlawful searches of the leather pouch and paper bag seized from his car trunk, the conviction is reversed and the case remanded for proceedings consistent with this opinion.
Reversed and remanded.
. The Supreme Court has granted certiorari in two search and seizure cases involving different, but related, issues: People v. Robbins, 103 *1161Cal.App.3d 34, 162 Cal.Rptr. 780 (1980), cert. granted, 449 U.S. 1109, 101 S.Ct. 916, 66 L.Ed.2d 838 (1981); People v. Belton, 50 N.Y.2d 447, 407 N.E.2d 420, 429 N.Y.S.2d 574 (1980), cert. granted, 449 U.S. 1109, 101 S.Ct. 917, 66 L.Ed.2d 838 (1981). In Robbins, application of the warrant exception for containers whose contents can be inferred from the packaging divided the lower court; in Belton, the scope of a search incident to an arrest is at issue.
. Brief for Appellee at 17 n.9 (urging that Sanders applies only to luggage and that neither pouch nor bag “is considered luggage in the sense that luggage is commonly known”).
. On April 17, 1980, a divided panel of this court held: 1) the currency found in the pouch should have been suppressed as evidence; 2) the Fourth Amendment does not forbid the police from opening a closed but untaped paper bag once it is properly in their hands. Had Ross “sealed the paper bag shut,” however, the panel majority would have held a search warrant required. See p. 1163, infra. The panel decision was later vacated and a rehearing en banc was held on October 23, 1980. In a brief prepared for the en banc hearing, the Government first argued that Sanders should not be applied retroactively. See pp. 1162-64, infra. But if Sanders applies to this case, the brief continued, the Government does not contest that the pouch is “the type of luggage contemplated by Sanders.” Supplemental Brief for Appellee at 7.
. Similarly difficult to administer, we think, is the protection the panel majority would have accorded a person’s legitimately seized paper bag sometimes. The panel majority distinguished between paper bags closed merely by folding a flap and bags sealed shut. It also distinguished the paper bag found in a car trunk “amidst suitcases” from one not surrounded by luggage. Slip op. at 15-16 n.6.
. Judge Wilkey’s dissenting opinion, post, at 1188-90, urges that the Supreme Court’s opinion in Peltier precludes this court from asking whether Sanders declared new law. It is true that the Court in Peltier did not set out this consideration as a separate inquiry, directing the courts instead to ask whether the police officer knew or should have known that his conduct was in accordance with the law. We believe, however, that the former inquiry is subsumed in the latter. If a decision develops no new law, then the police officer — who is charged with knowledge of the old law — should have known, and acted in a manner consistent with, the core doctrine.
. United States v. Stevie, 582 F.2d 1175 (8th Cir. 1978) (en banc), cert. denied, 443 U.S. 911, 99 S.Ct. 3102, 61 L.Ed.2d 876 (1979); United States v. Vallieres, 443 F.Supp. 186 (D.Conn. 1977); Sanders v. State, 262 Ark. 595, 559 S.W.2d 704 (1977), aff'd sub nom. Arkansas v. Sanders, 442 U.S. 753, 99 S.Ct. 2586, 61 L.Ed.2d 235 (1979); Shingleton v. State, 39 Md.App. 527, 387 A.2d 1134 (1978). Indeed, the Court in Sanders noted that the Supreme Court of Arkansas had found Chadwick “virtually controlling” on the questions Sanders presented. 442 U.S. at 762, 99 S.Ct. at 2592.
. See, e. g., United States v. Tramunti, 513 F.2d 1087, 1104-05 (2d Cir.), cert. denied, 423 U.S. 832, 96 S.Ct. 54, 46 L.Ed.2d 50 (1975); United States v. Soriano, 497 F.2d 147 (5th Cir. 1974) (en banc); United States v. Evans, 481 F.2d 990, 993-94 (9th Cir. 1973).
. Chadwick was decided on June 21, 1977. The searches in this case occurred on November 27, 1978. Sanders was decided on June 20, 1979.
. Judge Tamm expresses this point admirably in his opinion dissenting in part: “In any situation approaching a borderline case, the police would best be cautious, and obtain a proper search warrant before proceeding.” Post, at 1161 n.6.
. In Peltier, by contrast, the Court found that roving border patrol searches had received “continuous judicial approval” before Almeida-Sanchez v. United States, 413 U.S. 266, 93 S.Ct. 2535, 37 L.Ed.2d 596 (1973), the decision that was there denied retroactive effect. 422 U.S. at 541, 95 S.Ct. at 2319, Justice Powell’s opinion for the.Court in Aimeida-Sanchez had recognized that these searches “ha[d] been consistently approved by the judiciary” and presented a “question ... of first impression” to the Supreme Court. 413 U.S. at 278, 93 S.Ct. at 2542, quoted in Peltier, 422 U.S. at 541, 95 S.Ct. at 2319. Police officers conducting roving border patrol searches before Aimeida-Sanchez, therefore, did not have doubts about the constitutionality of their conduct; that conduct had been consistently approved by the federal courts. As explained above, however, Chadwick and the lower court decisions following it must have at least created a substantial doubt about the constitutionality of warrant-less searches of closed containers seized from automobiles.
. See note 3 supra.
. Under the criteria set forth in Chevron Oil Co. v. Huson, 404 U.S. 97, 105-07, 92 S.Ct. 349, 354-56, 30 L.Ed.2d 296 (1971), Salvucci should not apply retroactively to cases on direct appeal where the prosecution failed to challenge the defendant’s “standing” at the suppression hearing. While Chevron was a civil case, its reasoning is fully applicable in this context. United States v. Bowen, 500 F.2d 960, 975 n.l (9th Cir. 1974) (en banc), aff'd, 422 U.S. 916, 95 S.Ct. 2569, 45 L.Ed.2d 641 (1975). See also Linkletter v. Walker, 381 U.S. 618, 627, 85 S.Ct. 1731, 1736, 14 L.Ed.2d 601 (1965).
. See Cipriano v. City of Houma, 395 U.S. 701, 706, 89 S.Ct. 1897, 1900, 23 L.Ed.2d 647 (1969). Even the Government backs away, finding it “understandable” that Ross did not forecast Salvucci while his case was before the district court. Supplemental Brief for Appellee at 12 n.6.
. See text at pp. 1170-71 and notes 31, 33, and 34 infra.
. Cf. Arkansas v. Sanders, supra, 442 U.S. at 766-68, 99 S.Ct. at 2594-97 (Burger, C. J., concurring).
. E. g., United States v. Mannino, 635 F.2d 110 (2d Cir. 1980) (plastic bag); United States v. Mackey, 626 F.2d 684 (9th Cir. 1980) (paper bag); United States v. Blair, 493 F.Supp. 398, 416 (D.Md.1980) (cardboard boxes). Cf. United States v. Brown, 635 F.2d 1207 (6th Cir. 1980); United States v. Jimenez, 626 F.2d 39, 41 (7th Cir. 1980) (no expectation of privacy in paper bag on facts of this case, but facts in another case could show such an expectation), cert. granted, - U.S. -, 101 S.Ct. 3152, 69 L.Ed.2d 1000 (1980); United States v. Goshorn, 628 F.2d 697 (1st Cir. 1980) (remand for evidence whether defendant had expectation of privacy in paper bags). Several of the recent decisions distinguishing containers more or less closely resembling luggage (purses, wallets, guitar cases) from plastic or paper sacks cite the analysis in the now vacated panel decision in this case, which distinguished leather pouch from paper bag.
. 442 U.S. at 754, 99 S.Ct. at 2588.
. The car had been stopped for speeding. A patrol officer approached the car window and saw in plain view a large amount of currency and a gun case. The officer arrested the driver, removed the currency, opened the gun case, which contained a pistol and two fully-loaded clips, and further observed a suitcase in the hatchback. He then opened the suitcase and found incriminating evidence in it. 568 F.2d at 639.
. The police, engaged in surveillance for narcotics trafficking, had observed two incoming passengers at an airport, saw them load luggage into a rented station wagon, stopped the vehicle on the highway, arrested the occupants, looked for their luggage, and opened a suitcase found in the rear area of the station wagon. Inside were wrapped bricks of a substance later determined to be marijuana. 582 F.2d at 1176-77.
. Nor does the Ninth Circuit, which now applies Sanders whether suspicion is focused on a particular piece of luggage or on the car in general. United States v. Medina-Verdugo, 637 F.2d 649, 652-53 (9th Cir. 1980).
. Even if Sanders did not itself compel such a result, we would question the administrative feasibility of a distinction based on whether the object of suspicion is the car or the container. In some cases, for example, when an informant has supplied a precise tip, the object of suspicion may be clearly defined. But in many cases, an officer derives probable cause from the totality of the circumstances, after observing a vehicle’s movements and appearance, the demeanor and activities of its occupants, and the placement, transfer, or removal of containers to or from the vehicle. In such cases, it would demand too much to require the officer, after determining the existence of probable cause, to make the further assessment whether the car or the container is the “object of suspicion.”
. Ross argued before the three-judge panel that the police lacked probable cause to stop and search his car, but he has not pressed that objection before the full court. At any event, we believe it clear that the police had ample and reasonable cause to stop Ross and to search his car. The informer had supplied accurate information on prior occasions, and he was an eyewitness to sales of narcotics by Ross. He said he had just seen Ross take narcotics from the trunk of his car in making a sale and heard him say he possessed additional narcotics. See Spinelli v. United States, 393 U.S. 410, 89 S.Ct. 584, 21 L.Ed.2d 637 (1969); Aguilar v. Texas, 378 U.S. 108, 84 S.Ct. 1509, 12 L.Ed.2d 723 (1964); United States v. Davis, 617 F.2d 677, 692-93 (D.C.Cir.1979).
. Sanders, 442 U.S. at 763-64 n.l 1, 99 S.Ct. at 2593 n.ll.
. Carroll v. United States, 267 U.S. 132, 45 S.Ct. 280, 69 L.Ed.2d 543 (1925); Chambers v. Maroney, 399 U.S. 42, 90 S.Ct. 1975, 26 L.Ed.2d 419 (1970). See generally Moylan, The Automobile Exception: What it is and What it is not — A Rationale in Search of a Clearer Label, 27 Mercer L.Rev. 987 (1976); Note, The Automobile Exception to the Warrant Requirement: Speeding Away from the Fourth Amendment, 82 W.Va.L.Rev. 637, 637-56 (1980).
. As Sanders indicated, 442 U.S. at 763, 99 S.Ct. at 2592, the exception has been applied by the Court to integral parts of an automobile but not to items separately contained and temporarily stored in a car. See, e. g., South Dakota v. Opperman, 428 U.S. 364, 96 S.Ct. 3092, 49 L.Ed.2d 1000 (1976) (glove compartment); Texas v. White, 423 U.S. 67, 96 S.Ct. 304, 46 L.Ed.2d 209 (1975) (passenger compartment); Cady v. Dombrowski, 413 U.S. 433, 93 S.Ct. 2523, 37 L.Ed.2d 706 (1973) (trunk); Chambers v. Maroney, supra (concealed compartment under the dashboard); Carroll v. United States, supra (behind the upholstering of the seats).
. The Government does not contend, nor could it plausibly, that the officers were engaged in an “inventory search.” Cf. South Dakota v. Opperman, 428 U.S. 364, 96 S.Ct. 3092, 49 L.Ed.2d 1000 (1976).
. Cf. Amsterdam, supra, 58 Minn.L.Rev. at 403 (“[I]n the first and most important instance the fourth amendment speaks to the police and must speak to them intelligibly.”).
. In addition to the value or sturdiness of a container and the way in which it is closed, the panel majority in this case suggested another variable: an unimposing container — a paper bag — might not be subject to warrantless opening if the police found it “amidst suitcases.” Slip op. at 15-16 n.6. The paper bag in this case was found in the car trunk alongside a pouch that the Government now ranks as luggage. Would one luggage-like adjacent container suffice to upgrade the paper bag or would the bag remain vulnerable to on the spot warrantless search unless surrounded by several pieces of baggage?
. See United States v. Rivera, 486 F.Supp. 1025, 1034 (N.D.Tex.1980).
. Cf. The Washington Post, Dec. 15, 1980, at Cl, col. 3 (reporting that Arlene Robinson and her six children, aged 4 to 12, homeless and on welfare, “have lived a hand-to-mouth existence, mostly on the streets of Washington, with their few belongings stuffed into paper shopping bags”).
. Neither police nor court, consistently with the Fourth Amendment, can reason backward to determine that no warrant was required if the container searched in fact concealed evidence of crime. Similarly, as to the reasonableness of a privacy expectation, the innocence or evil of the goods concealed cannot determine Fourth Amendment protection. See United States v. Rivera, supra, 486 F.Supp. at 1031-32, 1034. One has no greater or lesser expectation of privacy in a bag when it contains drugs prescribed by a physician for an embarrassing ailment than when it contains contraband. Cf. United States v. Taborda, 635 F.2d 131, 138-39 n.10 (2d Cir. 1980).
. Cf. United States v. Sanders, 631 F.2d 1309 (8th Cir. 1980) (contents of a 2'h by 3 inch brown manila packet could be inferred from its outward appearance where agents knew that such packets were frequently used to carry cocaine or heroin, the packet was well-worn, and part of it was tom off); People v. Robbins, 103 Cal.App.3d 34, 162 Cal.Rptr. 780 (1980) (holding 2-1 that contents of “green wrapped plastic blocks” could be inferred from outward appearance), cert, granted, 449 U.S. 1109, 101 S.Ct. 916, 66 L.Ed.2d 838 (1981).
. Situated as they were in the locked car trunk, the pouch and bag surely were not “knowingly expose[d] to the public.” See Katz v. United States, 389 U.S. 347, 351-52, 88 S.Ct. 507, 511, 19 L.Ed.2d 576 (1967); cf. Note, War-rantless Searches and Seizures of Automobiles, 87 Harv.L.Rev. 807, 840 n.29 (1974). Placement of the closed sacks inside the locked trunk sufficiently exhibited Ross’s reasonable expectation that others would not peer or pry into his belongings. Cf. United States v. Taborda, supra, 635 F.2d at 136-39; United States v. Rivera, supra, 486 F.Supp. at 1031-34; Note, Tracking Katz: Beepers, Privacy, and the Fourth Amendment, 86 Yale L.J. 1461, 1472-77 (1977) (indicating that the concept “expectation of privacy” in Fourth Amendment cases is less than fully coherent, has produced confused and unprincipled decisions, and is in need of further Supreme Court attention and explication).
. See Yale Note, supra note 33, at 1482. Judge Tamm’s opinion dissenting in part, post, at 1177-1178, distinguishes paper bags from luggage partly on the basis that a paper bag, once out of its owner’s possession, is more susceptible to invasions by the curious or the dishonest. In this regard, we see no significant difference between the vulnerability of an unlocked suitcase, pouch, or wallet and that of a folded paper bag.