The defendant was convicted after a jury waived trial in the Superior Court on indictments for possession of cocaine with intent to distribute (G. L. c. 94C, §§ 31-32), possession of marihuana with intent to distribute {id.), and possession of a firearm without an identification card (G. L. c. 140, § 129C). He was sentenced to one year’s imprisonment for each offense, the terms to run concurrently.

On this appeal subject to G. L. c. 278, §§ 33A-33G, the assignments of error attack the judge’s failure upon voir dire to suppress the cocaine, marihuana, and firearm in question as having been seized illegally by the police. The facts brought out at voir dire were in outline these. Upon an affidavit referring to a tip, surveillance of premises, and overheard conversations, a search warrant issued on October 2,1972, for “certain rooms in the 2nd fl apt 2nd ft of 2 xh wooden dwelling house” at 22 Rosedale Street, Dorchester, a three-story building with one apartment on each floor. Under the warrant Boston police at about 10:15 p.m. that evening entered and searched the second-floor apartment, in which the defendant Hall and his wife resided, found there a small quantity of marihuana and a hand gun, and thereupon arrested the defendant’s wife ^[1] and two other persons present. They found papers indicating that the Halls owned the building (which was the fact); also keys to the front door of the building and to the unoccupied apartment on the third-floor which was in the course of being renovated. One of the officers was called to the street and received information that there was a larger quantity of drugs in the third-floor apartment. Having tried but failed because of the late hour to make arrangements to obtain a fresh search warrant for that apartment, the police after consulting a legal advisor of the Boston police department[*792] proceeded to search it nevertheless. Large quantities of cocaine and marihuana were found there sufficient if admissible to support the charges of “intent to distribute.” The defendant appeared at the apartment with another in the early morning and was also arrested.

The judge at voir dire made findings and rulings holding that the warrant for search of the second-floor apartment was adequately supported, and validating also the search of the third-floor apartment by reading the warrant to cover that apartment as an “extension” of the second-floor apartment. He also found the search, “under all the circumstances,” reasonable.

The defendant argues on this appeal, first, that all the evidence seized should have been suppressed because the affidavit on which the warrant issued was entirely invalidated by the inclusion in it of information secured through illegal eavesdropping in the hallway outside the second-floor apartment; if this illegality did not taint the entire document, then the rest was anyway insufficient to support the issuance of the warrant. Second, assuming that the warrant legalized search of the second-floor apartment and thus justified seizure of the hand gun and its reception in evidence, it could not be read to cover the third-floor apartment, and exigent circumstances did not exist that could legalize a warrantless search of that apartment; so the evidence consisting of the drugs found there should have been suppressed.

Our analysis leads us to the conclusion that the firearm was properly seized in the second-floor apartment and the conviction based thereon should be affirmed; but the seizure of the drugs in the third-floor apartment was illegal and the relevant convictions should be reversed.

1. The valid search of the second-floor apartment. We reproduce in the margin the text of the affidavit presented to the assistant clerk of the Municipal Court of the Dorchester District who issued the warrant. ^[2] It sets out[*793] three pieces of information: an informant’s tip, observations by police officers of “suspected users and dealers of Narcotics” entering and leaving the premises, and a report of conversations in the second-floor apartment about sale and use of drugs overheard by police officers. As to the overheard conversations, it appeared at voir dire that after receiving the tip (to be described below), the police on two evenings, September 30 and October 1, maintained a surveillance of the building and also eavesdropped on the landing and stairway outside the second-floor apartment.

A word is needed here about the layout of the building. Entrance to 22 Rosedale Street is through an unlocked door into a vestibule with two doors, and three doorbells to ring the three apartments. One of the doors opens into the first-floor apartment which is not a factor in this case. The second opens on an interior staircase leading to the defendant’s second-floor apartment and thence to the vacant third-floor apartment. The two doors off the downstairs vestibule are equipped with locks; the second door can be opened either with a key or by a buzzer mechanism from the upstairs apartments. That door was locked on October 2 when the police entered to execute their search under the warrant. However, on the two previous nights the police[*794] managed to pass the doorway without themselves using a key or ringing a doorbell as they proceeded to the second floor to listen to the sounds coming from the apartment. ^[3]

The judge concluded that this police eavesdropping did not infringe upon the defendant’s right of privacy, but we incline to disagree. The question cannot be answered by classifying “apartment hallway” as either a “protected” or “unprotected” area. Because “the Fourth Amendment protects people, not places,” Katz v. United States, 389 U. S. 347, 351 (1967), we must rather ask what expectation of privacy could be justifiably held by one engaging in conversation inside the particular second-floor apartment. See Warden v. Hayden, 387 U. S. 294 (1967); Texas v. Gonzales, 388 F. 2d 145 (5th Cir. 1968); Lorenzana v. Superior Court of Los Angeles, 9 Cal. 3d 626 (1973). In a typical apartment building the need of each tenant for privacy competes with the fact that other tenants and their guests and business invitees, the landlord’s caretaking employees, and still others, must also use such areas as hallways, stairs, lobbies, and cellars. This necessarily limits the individual tenant’s ability to control access to those places, and correspondingly his expectation of privacy. Our court has held, in line with other jurisdictions, that where a common area in an apartment building is not locked off, so that anyone can enter it, a tenant cannot complain if a policeman stationing himself there overhears a conversation in the apartment. Commonwealth v. Dinnall, ante, 165 (1974). Cf. Commonwealth v. Thomas, 358 Mass. 771 (1971). For other examples, see United States v. Llanes, 398 F. 2d 880 (2d Cir. 1968), cert. den. 393 U.S. 1032 (1969); United States v. Freeman, 426 F. 2d 1351 (9th Cir. 1970); United States v. Lewis, 227 F. Supp. 433 (S. D. N. Y. 1964); People v. Berutko, 71 Cal. 2d 84 (1969). But the present case is quite different from the Dinnall or Thomas case or the like. Here only the defendant lived behind the down[*795] stairs vestibule door and off the stairway to the second and third floors. Further, he was the owner of the building, not merely a tenant. The hallway was thus in his exclusive control; he did not share its use with other tenants or with an absentee landlord; and the arrangement made — the lock on the downstairs door and the buzzer system — was designed to exclude members of the public and to admit none but the defendant’s own guests and invitees. ^[4] See Commonwealth v. Dinnall, supra, at 167; Commonwealth v. Thomas, supra, at 773-775. A justified expectation of privacy therefore arose. ^[5] That the lock on the vestibule door could be and was bypassed on the two occasions when the eavesdropping took place cannot alter the picture, for police do not have carte blanche to pass through doors that are unlocked or even ajar if the area beyond has a private character. See Commonwealth v. Spofford, 343 Mass. 703, 705 (1962); Sabbath v. United States, 391 U. S. 585, 589-591 (1968); People v. Haven, 59 Cal. 2d 713, 715-717 (1963); People v. Williams, 24 App. Div. 2d(N. Y.)274, 276 (1965).

It follows that the overheard conversations may not be considered in deciding whether there was probable cause to issue the search warrant. Commonwealth v. Penta, 361 Mass. 894 (1972). United States v. Hunt, 496 F. 2d 888 (5th Cir. 1974). But the further question for decision is whether reference to those conversations in the affidavit fatally infected the warrant, supposing that the remaining evidence provided in the affidavit was legally obtained and would itself be enough to ground a finding of probable cause. Before the recent decision in United States v. Giordano, 416 U. S. 505 (1974), the answer would surely have been no. United States v. Sterling, 369 F. 2d 799, 802 (3d Cir. 1966). James v. United States, 418 F. 2d 1150, 1151-[*796] 1152 (D. C. Cir. 1969). Howell v. Cupp, 427 F. 2d 36, 38 (9th Cir. 1970). United States v. Tarrant, 460 F. 2d 701, 703-704 (5th Cir. 1972). United States v. Koonce, 485 F. 2d 374, 379 (8th Cir. 1973). United States v. Epstein, 240 F. Supp. 80, 82 (S. D. N. Y. 1965). As the court said in the James case, supra, it can hardly be thought in such a situation that the warrant is “fruit of the poisonous tree,” or that the warrant must be held void in order to effectuate a sound policy of deterring official lawlessness. 418 F. 2d at 1151-1152. But in the majority opinion in the Giordano case we find a discordant footnote of uncertain meaning. On a motion to suppress evidence secured by means of a court approved “pen register,” it appeared that the application for the pen register had referred to certain logs of conversations illegally monitored. Speaking of the illicit logs as “a critical element” (416 U. S. at 533-534, n. 19) in the approval of the use of the pen register, the Supreme Court, without apparently overruling the James line of cases, held that the evidence obtained by the pen register should be suppressed. But, as the opinion dissenting on that point noted, 416 U. S. at 548 (Powell, J., concurring in part and dissenting in part), a prior application for pen register authority, not referring to the logs of the wiretapped conversations, contained enough to show probable cause on which authority for a pen register could be granted; and the information from that original, approved, application was included in the later application which that court invalidated. Perhaps, then, “critical element” is to be taken as meaning an impressive or important element in relation to the totality of material put before the court, even though the rest would independently have merited that approval. ^[6] This would be a curious rule, for it would appear to invite speculation about how far the mind of the magistrate was affected by the several parts of the application. Reserving doubts about the Giordano proposition, we now try to fit it to our case.

[*797] We need to decide, first, whether the evidence apart from the overheard conversations provides probable cause. The major part of that material is the informant’s tip, and the defendant argues that it falls short of showing probable cause. Under Aguilar v. Texas, 378 U. S. 108, 114 (1964), there may be reliance on tips if the affidavit provides “some of the underlying circumstances from which the informant concluded that the narcotics were where he claimed they were, and some of the underlying circumstances from which the officer concluded that the informant . . . was ‘credible’ or his information ‘reliable’ ” (footnote omitted). See Spinelli v. United States, 393 U. S. 410, 415-416 (1969); Commonwealth v. Stewart, 358 Mass. 747, 750 (1971); Commonwealth v. Stevens, 362 Mass. 24, 27 (1972); Commonwealth v. Kane, 362 Mass. 656, 659 (1972); Commonwealth v. Avery, 365 Mass. 59, 62-63 (1974). Here there is a sufficient recital of prior police use of the informant to indicate that he was reliable. As to the “underlying circumstances” lending credit to his report, the affidavit tells us that the informant had a conversation about drug sales with a friend and a third person unknown to the informant; that the third person told the informant and friend to follow him to a house in Dorchester, which they did, the house being 22 Rosedale Street; that the friend and third person entered, the informant remaining outside; and that when the two emerged the third person told the informant that “he ^[7] sells good Cocaine and clean Grass,” whereupon the friend exhibited the white powder he had just bought from the third person; and that the third person invited the informant, if he was interested in buying some, to come to the second-floor apartment and use the friend’s name. The informant could thus reasonably infer on the basis of his own observations that the substance was cocaine and that it had come from the second-floor apartment. The Aguilar test is satisfied here, as our decisions and others ex[*798] pounding and applying Aguilar amply demonstrate. Commonwealth v. Avery, and Commonwealth v. Stewart, both supra. Commonwealth v. Snow, 363 Mass. 778, 782-784 (1973). See Spinelli v. United States, supra, at 416; United States v. Carter, 337 F. Supp. 604 (D. Minn. 1971), affd. sub nom. United States v. Smith, 462 F. 2d 456 (8th Cir. 1972). ^[8] To the tip must be added the observations by the police of suspected drug users and dealers entering and leaving the premises. ^[9] These lend further support to the belief that there were drugs in the second-floor apartment. See Commonwealth v. Anderson, 362 Mass. 74 (1972); Commonwealth v. Duran, 363 Mass. 229 (1973); Commonwealth v. Snow, supra, at 782-784.

Returning now to the Giordano point, when the foregoing evidence legally obtained is contrasted with the overheard conversations, the latter appear to be not a “critical element.” This is the case not only substantively but textually, for the overheard conversations are summarized in one sentence at the end of a rather long recital giving prominence to the contents of the tip. In the Giordano case the application for pen register authority set out verbatim the logs of the wiretapped conversations which, because of their length and vivid detail, would be likely to impress themselves sharply on the mind of the magistrate; there is no such long recital in the text of the illegally overheard conversations here. We conclude that the warrant authorizing the search of the second floor was valid, and it follows that the hand gun conviction should be upheld.

2. The invalid search of the third-floor apartment. Search of the third floor is another matter. The[*799] Commonwealth argues, and the judge agreed, that the third-floor apartment was only an “extension” of the second-floor apartment, and so was covered by the warrant. This argument is not persuasive. The warrant application recites “certain rooms in the 2nd fl apt 2nd fl of 2V2 wooden dwelling house” and the warrant refers to the same, which seems in terms to limit the scope of search to the second floor. Evidently the police on the scene understood the warrant that way, and so, apparently, did the advisor whose opinion they sought. No one requires elegant precision of these documents, but particularity is demanded of warrants by the Fourth Amendment itself, see Berger v. New York, 388 U. S. 41, 58-59 (1967); United States v. Wroblewski, 105 F. 2d 444, 446 (7th Cir. 1939), and they are to be read without poetic license. A case resembling ours is Keiningham v. United States, 287 F. 2d 126 (D. C. Cir. 1960), where a warrant for “1106 Eighteenth Street N. W.” was held not to allow search of the adjoining row house at 1108 even though the police found a door cut into the wall between the two houses and the defendants were shown to have used both as a single unit. Rejecting the contention that because of that use the warrant for 1106 should “somehow be construed” to cover 1108 as well, the court said at 129, “The authority to search is limited to the place described in the warrant and does not include additional or different places.” Other cases of similar import are cited in the margin. ^[10] Although, as we have said, the defendant had[*800] a reasonable expectation of privacy in the hallway because of his control of the area leading from the vestibule door, it does not follow that a reference to “certain rooms in the 2nd fl apt 2nd fl” can be interpreted to comprise the third floor as well; rather cases like United States v. Hinton, 219 F. 2d 324 (7th Cir, 1955), apply, which hold that different apartments' in a single building are as distinct as separate dwelling houses, so that a separate warrant on probable cause is ordinarily needed for each. Cases like State v. Brochu, 237 Atl. 2d 418 (Maine, 1967), in which a warrant for a private house was held to allow search of the garage also, or Fine v. United States, 207 F. 2d 324 (6th Cir. 1953), allowing such a warrant to embrace a shed in the yard, are not to the contrary; as such cases make clear, a reference to a detached single house or dwelling is commonly understood to take in the whole property, including subsidiary structures. ^[11]

But if the warrant is not to be read to cover the third floor, we have to turn to the question whether a warrantless search could be justified as being based on probable cause and occurring in “exigent circumstances.” Probable cause can, we think, be pieced out. To the data in hand when the second-floor search was completed, including the fact that the defendant owned the building, and that keys to the vacant third-floor apartment were in the second-floor apartment, we are to add the information received by the officer called to the street. This was the officer who knew the reliable informant; he was one of five officers in the building carrying out the search. Two colleagues, stationed outside the building in an unmarked car, with commu[*801] nication facilities to those inside and to the police station, summoned the officer downstairs by means of a walkie-talkie. The informant, waiting around the comer, told the officer that he had been trying to reach him since 6 p.m. to say that the “main stash” was in the unoccupied third-floor apartment. Someone else, said the informant, had gone between 5 and 6 p.m. to buy drugs and the defendant had gone upstairs to get them. That other person was the informant’s girl friend whom the officer had met previously; she had been present on occasions when the informant had given the officer information, but she had never before supplied information. Now the officer telephoned her (the informant dialed hemumber) and she confirmed the informant’s story. Her own reliability was unproved. Nevertheless we believe the sum total of previously available information, when combined with her story, provided probable cause for a search of the third floor. Cf. Commonwealth v. Stewart, 358 Mass. 747 (1971); Commonwealth v. Snow, 363 Mass. 778 (1973).

The police now sought advice from the assistant to the departmental legal advisor as to what to do about the third floor. He advised them to get a fresh warrant, otherwise to call him again. The police telephoned a number of clerks of the Municipal Court of the Dorchester District but evidently reached but one, who said he had no key to the court house. We may accept the judge’s finding that the police acted diligently in seeking a warrant, although they were aware that on other occasions warrants had been issued by clerks from their homes. Responding to a further call — it was now near midnight — the assistant legal advisor told the police they could enter the third-floor apartment with the Halls’ key. They did so and found the cocaine and marihuana.

In our opinion the commendable effort of the police to stay within the law did not succeed, as the circumstances cannot be held “exigent.” Supreme Court authority from Johnson v. United States, 333 U. S. 10 (1948), to Vale v. Louisiana 399 U. S. 30 (1970), establishes strict standards as to exigency, ánd the burden of showing it is on the[*802] Commonwealth. Vale v. Louisiana, supra, at 34. McDonald v. United States, 335 U. S. 451, 456 (1948). Cf. Commonwealth v. Antobenedetto, ante, 51 (1974). In the Vale case the court refused to validate a warrantless search of a house following an arrest in front of the house; the fact that narcotics, in the house could be easily removed, hidden, or destroyed was irrelevant since the police knew there was no one inside the house. Just so in the present case it appeared at voir dire that the police knew there was no one in the third-floor apartment. In the Vale case, to be sure, the majority of the court may have been somewhat affected by their belief that the police could have obtained a search warrant before they went to make the arrest, ^[12] but in the Johnson case there was no prior opportunity, yet the court reached the same result: the warrantless search of a hotel room, based on the detection of the odor of opium from outside, was held illegal because it was not shown that the evidence was threatened with removal or destruction. Even if we assume a requirement of a “threat” of destruction or removal, as in the Johnson case, 333 U. S. at 15, ^[13] instead of the possibly tighter requirement, suggested by the more recent Vale case, that the goods be “in the process of destruction,” or “about to be removed from the jurisdiction,” 399 U. S. at 35, the search here still does not fit the “exigent” category, for in the cases held “exigent” a quite specific threat has been found: “based on the surrounding circumstances or the information at hand” it is reasonably concluded that “the evidence will be destroyed or removed before... [the police] can secure a search warrant.” United States v. Rubin, 474 F. 2d 262, 268 (3d Cir. 1973). The proposition is exemplified in many situations. ^[14] In our case[*803] the evidence could be destroyed or removed only if someone, not on the premises, returned and managed to get into the third-floor apartment. That such a possibility by itself is not enough to establish exigent circumstances is clear from the Vale case and other decisions. ^[15] A number of police officers were on hand; they could readily have maintained a presence to prevent suspicious access to the premises until a warrant could be obtained. ^[16] United States v. Goldenstein, United States v. Nelson, United States v. One 1949 Buick Sedanette, and United States v. Costa, all supra. See Note, Police Practices and the Threatened Destruction of Tangible Evidence, 84 Harv. L. Rev. 1465, 1474-1476 (1971). ^[17] To avoid intrusion on any privacy, the[*804] police could have retreated to the vestibule. And since those present in the second-floor apartment had already been arrested, and on the basis of evidence found there the police had grounds and intended to and did in fact arrest the defendant when he appeared, there was no one with a cognizable right of entry into the premises who could complain of its curtailment by the police. See Note, supra, at 1471-1481.

The delay facing the police before they could obtain a warrant was not one or two hours but perhaps as much as eight hours, but the cases do not suggest that the result should turn on such measurements of time; rather the question is whether the longer delay introduces a substantially greater risk of loss or destruction of evidence or of harm to the police. ^[18] No such showing of increased risk was made here. It is significant that the police did not balk at waiting the length of time needed to apply for and secure a fresh warrant if a court clerk were available. There was no showing that the police feared the appearance during the longer period of confederates bent on preventing seizure of a possible cache in the third-floor apartment or threatening or attacking the police; had any associates of the Halls appeared, they could, as noted, have been denied entrance. The Commonwealth on all the facts thus failed to meet its burden of showing exigency, and the third-floor search must be held illegal.

Judgment of conviction for possession of firearm affirmed; other judgments reversed and findings set aside.