The Commonwealth appeals from an order entered in the Superior Court suppressing cocaine, heroin, and marijuana seized by the police from the defendant’s apartment. After the *235door to the apartment was opened by a woman, the police entered the apartment and the drugs were observed in plain view. The judge held an evidentiary hearing and entered a memorandum of decision and order in which he ordered suppression of the drugs. A single justice of this court granted the Commonwealth leave to pursue an interlocutory appeal from the judge’s order in the Appeals Court, see Mass. R. Crim. R 15 (a) (2), as appearing in 422 Mass. 1501 (1996), and we transferred the case to this court on our own motion.
In his decision, the motion judge implicitly assumed that the woman who answered the door consented to the police entry, but ruled that she lacked actual authority to consent and that there was insufficient evidence for the police reasonably to believe that she had apparent authority. As explained below, we affirm the order suppressing the Commonwealth’s evidence, but we do so for reasons other than those relied on by the judge. We do not reach the questions of actual or apparent authority which he decided, for we conclude that the evidence did not establish even that the woman at the door consented to the entry.1
1. Facts. We summarize the judge’s findings of fact.2 On August 21, 2002, at approximately 4:40 a.m., Officer Joshua Ellsworth of the Springfield police department encountered a woman who was crying. When the officer asked her if she needed assistance, the woman identified herself and said that she had gone to “Danny’s apartment” to buy crack cocaine. She told the officer that, after she had paid for the drugs, Danny and a woman named “Rose” had assaulted her and taken back the drugs. The victim described the apartment to the officer. *236Ellsworth concluded that “Danny” was the defendant, Daniel Rogers, and that “Rose” was a woman he had seen in Rogers’s company. Ellsworth had been to Rogers’s apartment (which was approximately two and one-half blocks from where he met the woman) at least ten times during the past year in response to complaints of drug use, fights, and prostitution. Because of his frequent visits, the officer recognized the layout of the defendant’s apartment as described by the woman.
Ellsworth and two other officers, all in uniform, proceeded to Danny’s apartment. Ellsworth knocked on the door and a woman he recognized as Rose Hopkins opened the door. Several other people were also inside the apartment. The officer asked where he could find Rogers. Rose and two other unidentified individuals pointed in the direction of the kitchen. Due to his familiarity with the apartment, the officer knew that the kitchen was in the rear of the apartment. He walked through the living room area to the back of the apartment where he found Rogers seated at a table. A large pile of what Ellsworth recognized as crack cocaine was on the table in front of Rogers.3 The police seized the cocaine and also some marijuana that was on a nearby shelf. It was later determined that the seized contraband also included heroin.
The defendant was indicted for possession with intent to distribute cocaine as a subsequent offense, G. L. c. 94C, § 32A (c) and (d); violation of the controlled substance laws in, on, or near a school or park zone, G. L. c. 94C, § 321; possession of a class A substance (heroin), G. L. c. 94C, § 34; and possession of a class D substance (marijuana), G. L. c. 94C, § 34.
2. Discussion. Warrantless entries into the home are prohibited by the Fourth Amendment to the United States Constitution and art. 14 of the Massachusetts Declaration of Rights absent either probable cause and exigent circumstances, or consent. See Commonwealth v. Voisine, 414 Mass. 772, 783 (1993), quoting Commonwealth v. Derosia, 402 Mass. 284, 286, cert. denied, 488 U.S. 980 (1988); Commonwealth v. Pietrass, *237392 Mass. 892, 897 (1984). The reason for the rule against warrantless entry “is to protect the physical integrity of the home from warrantless police intrusion.” Commonwealth v. Sanna, 424 Mass. 92, 96 n.9 (1997). In the present case, the Commonwealth does not justify its entry of the defendant’s home based on probable cause and exigent circumstances; thus the only issue for consideration is whether the police had consent to enter the defendant’s home. When the police rely on consent to justify a warrantless entry, under both the Fourth Amendment and art. 14, the prosecution “has the burden of proving that the consent was, in fact, freely and voluntarily given.” Bumper v. North Carolina, 391 U.S. 543, 548 (1968). See Commonwealth v. Walker, 370 Mass. 548, 554-555, cert. denied, 429 U.S. 943 (1976), citing Bumper v. North Carolina, supra; Commonwealth v. Sanna, supra at 97; Commonwealth v. Aguiar, 370 Mass. 490, 496 (1976). Because entry based on consent is an exception to the constitutional warrant requirement, “the Commonwealth must show ‘consent unfettered by coercion, express or implied, and also something more than mere “acquiescence to a claim of lawful authority.” ’ ” Commonwealth v. Voisine, supra at 783, quoting Commonwealth v. Walker, supra at 555. See Bumper v. North Carolina, supra at 549-550; Commonwealth v. Robinson, 399 Mass. 209, 217 (1987). See also Schneckloth v. Bustamonte, 412 U.S. 218, 228 (1973) (“the Fourth and Fourteenth Amendments require that a consent not be coerced, by explicit or implicit means .... For, no matter how subtly the coercion was applied, the resulting ‘consent’ would be no more than a pretext for the unjustified police intrusion against which the Fourth Amendment is directed”)4; Commonwealth v. Sanna, supra at 96-97. Although consent may be implicit, see Commonwealth v. Voisine, supra, *238and the police need not utter any “magic words” of request before entering, the Commonwealth must establish that the occupant’s words or conduct amounted to something other than mere acquiescence to a claim of authority or simple resignation to the perceived power of uniformed officials.
The voluntariness of an individual’s consent to a warrantless entry is an issue of fact, and must be examined in light of the totality of the circumstances of the case. See Schneckloth v. Bustamonte, supra at 248-249; Commonwealth v. Sanna, supra at 97. Ordinarily, in cases involving consent to enter a defendant’s home, entry is preceded by an exchange in which a police officer makes some type of inquiry of an occupant, and in response, the occupant verbally or physically reacts in a manner that is interpreted as “consent.” See, e.g., Commonwealth v. Voisine, supra at 776. Whether consent is voluntary depends on the nature of this interaction between the police and the occupant. Commonwealth v. Walker, supra (“In considering all the circumstances, we must take into account not only the conduct of the police but also the conduct and statements of persons inside the apartment prior to the police entry”). In meeting its burden of establishing voluntary consent to enter, the Commonwealth must provide us with more than an ambigú-pus set of facts that leaves us guessing about the meaning of this interaction and, ultimately, the occupant’s words or actions. See Schneckloth v. Bustamonte, supra at 228-229, quoting Boyd v. United States, 116 U.S. 616, 635 (1886) (consent by coercion “can only be obviated by adhering to the rule that constitutional provisions for the security of person and property should be liberally construed. A close and literal construction deprives them of half their efficacy, and leads to gradual depreciation of the right”). See also United States v. Patacchia, 602 F.2d 218, 219 (9th Cir. 1979) (“existence of consent to a search [or entry] is not lightly to be inferred”); Commonwealth v. Marquez, 434 Mass. 370, 374 (2001), quoting Commonwealth v. Forde, 367 Mass. 798, 805 (1975) (“The right of police officers to enter into a home, for whatever purpose, represents a serious governmental intrusion into one’s privacy”). If either the of-*239fleer’s request or the occupant’s response is so ambiguous that we are unable to discern whether the occupant voluntarily consented to entry, our inquiry will be over and the entry must be deemed unlawful. Thus, “[w]e must first determine whether [Rose’s] actions could reasonably be interpreted to manifest consent to the officers’ entry into the apartment. Once the existence of a consent by conduct is determined, its voluntariness must be examined.” United States v. Griffin, 530 F.2d 739, 743 (7th Cir. 1976). See Robbins v. MacKenzie, 364 F.2d 45, 48 (1st Cir.), cert. denied, 385 U.S. 913 (1966) (first examining whether evidence warranted finding that occupant expressed consent to entry, then whether consent was coerced).
a. Ambiguity. With the requirements discussed above as our guide, we must first determine whether, based on the circumstances of the interaction between Rose and the police, Rose consented to the entry. We consider the exchange at issue in the present case in chronological order, first analyzing the officer’s request of the occupant, and then considering her response. All Officer Ellsworth asked Rose was where he could find the defendant. This question can be interpreted narrowly as merely a question concerning the whereabouts of the defendant, more broadly as including a request to enter the premises, or as an expression of the officers’ intention to enter the defendant’s home, regardless of the occupants’ response and irrespective of whether they were given permission to do so. Rose’s response of stepping back and pointing toward the kitchen similarly may be construed in more than one way: as strictly an indication of the defendant’s location, or as a manifestation of Rose’s permission for the officers to enter to speak with the defendant in the kitchen. Thus, at the very outset of our analysis, the ambiguity of both the officers’ and Rose’s words and actions makes it difficult to discern whether there was actual consent in this case. See United States v. Shaibu, 920 F.2d 1423, 1427 (9th Cir. 1990) (to infer voluntary consent from occupant’s actions in walking toward officers in hallway, then walking back into apartment and leaving door open in response to inquiry from officer about whereabouts of suspect, would be “conjecture”); Holmes v. State, 347 Ark. 530, 540 (2002) (occupant’s opening door and stepping back in response to question about where of*240ficers could talk with occupant was marked by “uncertainty and lack of clarity” and did not constitute consent to enter). The dissent, through inference, would disregard the indeterminate nature of the interaction at issue and conclude that Rose’s “gesture . . . [was] neither ambiguously or equivocally conveyed.” Post at 250 (Greaney, J., dissenting). We simply cannot not infer so much from so little.
Where courts have found that an occupant’s gesture or her stepping aside or back from a threshold amounts to consent to enter, these actions have often been in response to what could reasonably be construed as a request to enter by the police or an explicit disclosure of their purpose. The more precise information and requests provided by the officers in these cases, which are absent in the present case, serve to clarify the meaning of the occupants’ reactions as manifestations of their consent for the police to enter. For example, in Robbins v. MacKenzie, supra at 49, only after the police officer knocked and identified himself and stated his purpose did the occupant make a “responsive gesture of invitation” by unlocking and opening the door and walking back into the room. In construing the gesture as a voluntary invitation to enter, the United States Court of Appeals for the First Circuit emphasized the significance of the officer having first “fully and honestly informed [the occupant] of [his] objective)].” Id. Officers’ more explicit requests have served to elucidate occupants’ responsive gestures in other cases. See United States v. Carter, 378 F.3d 584, 587-588 (6th Cir. 2004), cert. denied, 125 S. Ct. 1298 (2005) (finding consent where officers explicitly asked to enter hotel room and speak with occupant and occupant then stepped back and “cleared a path” for officers to enter); United States v. Griffin, supra at 741, 743 (only after rejecting officers’ first request to enter apartment and in response to second request to enter did occupant “step[] back, leaving the door open, and [lead] the officers into the apartment”); United States v. Ramirez-Chilel, 289 F.3d 744, 746-747 (11th Cir. 2002), cert. denied, 537 U.S. 1114 (2003) (police stated purpose and requested entry prior to occupant’s “yielding] the right-of-way”); United States v. Zabala, 52 F. Supp. 2d 377, 385 (S.D.N.Y. 1999) (officer testified that he asked “if [he and other officers] can take a look *241inside,” and in response, occupant unlocked and opened door with her key). The instant case, characterized by the absence of a request to enter or any explanation of the officers’ purpose, and only an indeterminate reaction by Rose, is distinguishable from these cases.
b. Voluntariness. Even should we assume that Rose’s actions were an unambiguous signal allowing the police to enter the apartment, the Commonwealth has failed to satisfy its burden of proof that Rose’s alleged consent was sufficiently voluntary to comply with the requirements for a warrantless search. It was between 4:40 a.m. and 5 a.m. when Rose opened the door to find three uniformed officers standing at the threshold. Cf. Commonwealth v. Harmond, 316 Mass. 557, 561-562 (1978) (although not conclusive, “presence of several uniformed officers . . . may suggest the absence of consent” in context of war-rantless search). According to the undisputed testimony, the of-fleers were armed. They did not identify themselves before or while knocking on the door, and it is likely Rose was unaware of their identity until after she opened the door. As the officers never stated their purpose, Rose probably did not know at the time she pointed whether the officers merely intended to ques-tian Danny, or whether they came to arrest him or search the home. Contrast Robbins v. MacKenzie, supra at 48-49.
In the circumstances of this case, the Commonwealth has failed to demonstrate that Officer Ellsworth’s question concem-ing the defendant’s whereabouts was not a demand for entry, and that Rose’s response thereto was anything other than “mere acquiescence” to a claim of authority. See Johnson v. United States, 333 U.S. 10, 12-13 (1948) (consent invalid as “granted in submission to authority rather than as an understanding and intentional waiver of a constitutional right” where defendant “stepped back acquiescently” and admitted police into hotel room); United States v. Edmondson, 791 F.2d 1512, 1514, 1515 (11th Cir. 1986) (defendant’s response of stepping back and putting hands on head in response to demand, “FBI. Open the door,” was merely “acquiescence to a show of official authority,” not consent for agents to enter). Contrast Commonwealth v. Sanna, 424 Mass. 92, 94, n.2, 97-98 (1997) (consent “freely and voluntarily given” where, in response to request for permis*242sion to enter house to ask defendant questions, defendant’s father “invited the officers into the house, telling them ‘Come on inside,’ gestured] toward the door of the house, and [led] the officers . . . into the living room”; he testified that “he neither feared the officers nor did he feel uncomfortable about their entry into his house”); Commonwealth v. Walker, 370 Mass. 548, 555-556 (1970) (voluntary consent found in “atmosphere of tension and fear” where “only element of fear was injected by the defendant’s conduct” and “[occupant] was frightened — not of the police, but of the defendant [in the house] and what he might do to avoid arrest”); United States v. Tobin, 923 F.2d 1506, 1512 (11th Cir. 1991) (decision to open door voluntary where officer first called out to occupants and then requested to speak with them about drugs in garage, and “did not use [an] imperative . . . [but] phrased his words in the form of a request [so that the occupants] were free to deny that request or alternatively talk to the agent through the closed door”); Robbins v. MacKenzie, supra. The multiple ambiguities in the officer’s question and Rose’s response only compound the deficiency of the Commonwealth’s assertion that Rose voluntarily consented to the entry.
The Commonwealth points to several cases where courts have found voluntary consent in support of its argument that such consent existed here. Under a totality of the circumstances analysis, such as that employed to determine the voluntariness of consent, each case necessarily turns on its facts. See Schneckloth v. Bustamonte, 412 U.S. 218, 233 (1973) (ascertaining whether consent is voluntary involves “careful sifting of the unique facts and circumstances of each case”). It is not surprising, then, that courts, including this one, have found voluntary consent in some cases in spite of the existence of some coercive factors absent in the instant case. However, of the relevant cases cited by the Commonwealth, all are distinguishable from the case before us in that they contain significant indicia of voluntariness not present here. Moreover, the officer-occupant exchanges that preceded entry in many of these cases lack the ambiguity that is fatal to the Commonwealth’s claim of consent in this matter. In United States v. Walls, 225 F.3d 858, 862 (7th *243Cir. 2000), for instance, the occupants initially refused entry to the agents who first knocked at the door. The occupants, who were “neither intimidated by the agents’ presence nor ignorant of the right to refuse entrance,” first shouted at the agents that they could not enter and that they needed a warrant. Id. Only after the agents identified themselves and told the occupants that they were conducting an investigation about two packages that had been delivered did the defendant open the door, step back to allow entry, and then motion to the agents for them to follow her into the kitchen. Id. See United States v. Griffin, 530 F.2d 739, 741, 743 (7th Cir. 1976) (finding voluntary consent where, in response to second request to enter, occupant “stepped back, leaving the door open, and led the officers into the apartment”; officers first explained basis for wanting to enter, defendant responded “no” to first request and shut door in their faces, indicating awareness of right to refuse entry and lack of intimidation by officers’ authority); Davis v. United States, 327 F.2d 301, 302 (9th Cir. 1964) (officer in plain clothes knocked on defendant’s door at noontime, said, “I would like to talk to Albert Davis,” and in response, young girl said, “Come in”); United States v. Ramirez-Chilel, 289 F.3d 744, 746-747 (11th Cir. 2002) (police stated purpose and requested entry); People v. Lozano, 316 Ill. App. 3d 505, 510-511 (2000) (police sergeant had asked “if they could come in to find out what had happened” and that defendant, who was himself a police officer, voluntarily consented by opening door and stepping aside); State v. Tomlinson, 254 Wis. 2d 502, 517, 524 (2002) (consent to enter found where occupant opened door and walked into house in response to officer’s request for permission to enter house; occupant did not claim coercion or duress).
The Commonwealth also relies on Commonwealth v. Voisine, 414 Mass. 772 (1993), for the proposition that Rose’s act of pointing to the kitchen was sufficiently consensual. There, however, the woman (who was the apartment lessee) testified at the hearing on the motion to suppress that she was aware of her right not to admit the police, but nonetheless chose voluntarily to let the police enter. Id. at 783. The court relied heavily on that testimony in finding voluntary consent. Id. Here, Rose did not testify; she made no concession as to the voluntariness of *244any consent; and there is insufficient evidence on the record before us to establish it. The Commonwealth also points to the case of Commonwealth v. Hill, 57 Mass. App. Ct. 240, 244 (2003), for support that where an occupant “freely step[s] aside,” such an action manifests consent. However, there were additional indicia of voluntariness not present in the instant case. The defendant in the Hill case, who answered the door only after, and in response to, the officers’ second visit, “knew who [the officers] were, asked them what they wanted, and freely stepped aside allowing them to enter the apartment.” Id.
The dissent attempts to justify the police entry in this case on a variety of theories, some of which even the Commonwealth has not asserted. According to the dissent, “[i]f the conduct viewed objectively is reasonable, the police have violated no right, constitutional or otherwise.” Post at 247. While both the United States and Massachusetts Constitutions require that police conduct be “reasonable,” more is required than merely a label. The reasonableness of a warrantless entry based on consent is measured according to more specific criteria; the prosecution must show that the consent was truly voluntary, “unfettered by coercion, express or implied.” Commonwealth v. Voisine, supra at 783, quoting Commonwealth v. Walker, supra at 555. Only if voluntary consent is in fact given can we say that the police were “reasonable” in entering the home. Absent voluntary consent, we do not rely on our own notions of “reasonableness” to justify the entry. Recognizing the well-established doctrine of voluntary consent, the Commonwealth has not sought to establish lawful entry on a showing that the officers’ conduct was somehow independently “reasonable,” and we will not depart from our case law to do so.
In a similar vein, the dissent suggests that the entry here might be justified on the basis of exigent circumstances. The dissent infers that the crime was “evanescent” and would “ ‘go by the boards,’ if not immediately responded to” and that “the police would have been derelict in their duty to leave Dysili’s report unattended to while they fretted over the need to get a warrant or to do something else to gain ‘official’ entry to the defendant’s apartment.” Post at 248. Again, the Commonwealth *245does not rely on a claim of probable cause and exigent circumstances. Had the Commonwealth believed probable cause and exigent circumstances justified entry, surely it would have so argued. Instead, the Commonwealth seeks to justify the police entry into the defendant’s home on one basis only — Rose’s alleged voluntary consent. Having relied exclusively on a theory of consent, consent must be established. In requiring that the Commonwealth prove that consent, we are in no way suggesting that the police should not have “responded to” Dysili’s report that she had just been attacked or that they should have left Dysili’s report “unattended to.” Post at 248. We merely insist— as we always do — that the police response remain within constitutional bounds.
In addressing the ultimate question presented, “whether Rose actually consented to the entry,” post at 249, the dissent in ef-feet shifts the burden with respect to the voluntariness of consent from the Commonwealth to the defendant. Tellingly, Justice Greaney writes, “[h]ad the defendant adequately raised this theory of suppression [i.e., voluntariness] at the hearing, the judge undoubtedly would have provided more detailed findings regarding the issue of voluntariness.” Post at 250. Yet it is not incumbent on the defendant to refute all possible theories that might justify legal entry into the home. On the contrary, it is the Commonwealth’s obligation to establish its theory of entry and prove lawful entry based on that theory. See Commonwealth v. Walker, supra at 554-555, citing Bumper v. North Carolina, 391 U.S. 543, 548 (1968). See also Commonwealth v. Sanna, 424 Mass. 92, 97-98 (1997); Commonwealth v. Aguiar, 370 Mass. 490, 496 (1976). The Commonwealth bears this burden regardless whether the defendant has, or is planning, to challenge any aspect of that theory.
The dissent also focuses on the fact that the officers “did not try to conceal . . . their identity or their purpose,” “used no trickery” and did not “attempt to frighten or intimidate” the occupants. Post at 250-251. The key issue here is not whether the officers intended to coerce Rose into assenting to entry, but whether, due to the circumstances surrounding entry, Rose was intimidated to the extent that her alleged consent was not voluntary. Similarly, that the officers may not have engaged in *246blatant intimidation is not, by itself, sufficient proof that an occupant’s consent is voluntary. “Subtle coercion, in the form of an assertion of authority or color of office by the law enforcement officers may make what appears to be a voluntary act an involuntary one.” United States v. Griffin, 530 F.2d 739, 742 (7th Cir. 1976). In analyzing the totality of the circumstances, courts have found a lack of voluntary consent even in the absence of overt intimidation by the police. See, e.g., United States v. Shaibu, 920 F.2d 1423, 1427 (9th Cir. 1990); Holmes v. State, 347 Ark. 530, 540 (2002). Similarly, that Rose “did not object, turn away, or call the defendant to the door,” post at 250, on this record, is equally inadequate to establish voluntary consent. See United States v. Shaibu, supra, quoting Johnson v. United States, 333 U.S. 10, 17 (1948) (“The government may not show consent to enter from the defendant’s failure to object to the entry. To do so would be to justify entry by consent and consent by entry. ‘This will not do’ ”). See also Holmes v. State, supra at 539.
Finally, the dissent suggests that our holding today amounts to a “heightened constitutional standard,” post at 254, that would require the officers in this case to have either obtained a warrant or “explicit[ly] wam[ed] [the occupant] of the right to refuse consent.” Ibid. We would require neither. As illustrated by the cases discussed above, there are various means, short of explicit advice to the occupant about her right to refuse consent, that would take no more time and employ no more resources than the approach taken by the officers in this case, by which the police may make clear that they are merely requesting permission to enter, not demanding entry. See, e.g., United States v. Walls, 225 F.3d 858, 862 (7th Cir. 2000); United States v. Tobin, 923 F.2d 1506, 1529 (11th Cir. 1991); United States v. Griffin, supra; People v. Lozano, 316 Ill. App. 3d 505, 510 (2000); State v. Tomlinson, 254 Wis. 2d 502, 524 (2002). Instead, we affirm today what we have long held: where, as here, the police choose not to obtain a warrant, and probable cause and exigent circumstances are absent, the Commonwealth must establish voluntary consent. Such consent must be shown to be more than mere conjecture and its voluntariness something *247other than capitulation to official authority. See discussion, supra. We do not change our law today; we simply apply existing law to the facts of the case. While society does indeed have a “substantial interest in the continuation of consent entries,” post at 255, so too do we have an interest in protecting the home from entries obtained through coercive means in violation of the Constitution. Because we cannot discern that voluntary consent was given in the circumstances of this case, the Commonwealth has not carried its burden under the Fourth Amendment and art. 14. Therefore, we do not reach the question whether Rose had authority to permit the entry into the defendant’s home or whether the police reasonably believed that she did.
3. Conclusion. The order allowing the motion to suppress the drugs seized dining the search of the defendant’s apartment is affirmed.
So ordered.
The Commonwealth maintains that the defendant has waived the issue whether the woman’s consent to enter was voluntarily given. The defendant did not waive this issue as he raised it at the conclusion of the hearing on the motion to suppress as well as in his posthearing memorandum. In any event, an appellate court may affirm a ruling on an alternative legal theory if supported by the record and the findings. See Commonwealth v. Va Meng Joe, 425 Mass. 99, 102 (1997), and cases cited. The judge’s findings are sufficient to permit us to reach our conclusion.
Although the judge’s findings are “binding in the absence of clear error,” we may reexamine his conclusions of law. See Commonwealth v. Alvarado, 420 Mass. 542, 544 (1995), quoting Commonwealth v. Bottari, 395 Mass. 777, 780 (1985).
There is no dispute that the evidence was in plain view once the officers entered the kitchen area of the apartment. See Commonwealth v. Pietrass, 392 Mass. 892, 901 n.12 (1984), citing Commonwealth v. Hason, 387 Mass. 169, 176 (1982).
While the Court in Schneckloth v. Bustamonte, 412 U.S. 218, 229 (1973), declined to require that the prosecution “affirmatively prove that the subject of the search [or entry] knew that he had a right to refuse consent,” i.e., that a waiver be “knowing and intelligent,” id. at 235, the Court reaffirmed that “the Fourth and Fourteenth Amendments require that [the prosecution] demonstrate that the consent was in fact voluntarily given, and not the result of duress or coercion, express or implied” and that “[v]oluntariness ... be determined from all the circumstances.” Id. at 248-249. Just as the Bustamonte Court was concerned that requiring a “knowing and intelligent” waiver would create “artificial restrictions” on police conduct, so too was it mindful *238that “[t]o approve such searches [or entries] without the most careful scrutiny would sanction the possibility of official coercion.” Id. at 229.