In this interlocutory appeal,1 the Commonwealth challenges the allowance of the defendant’s motion to suppress *816evidence in the District Court, where the defendant was charged with unlawful possession of a firearm, G. L. c. 269, § 10(a); possession of a firearm without an identification card, G. L. c. 269, § 10(h), and possession of marijuana, G. L. c. 94C, § 34. The Commonwealth contends that tire judge erroneously allowed the defendant’s motion on the basis that it was unreasonable for the officer to believe that the woman who opened the door to a motel room had actual or apparent authority to consent to his entry into the room.2 For the reasons that follow, we conclude that the judge erred.
Background. The following are the relevant facts found by the judge, “supplemented by uncontroverted facts adduced at the hearing.” Commonwealth v. Torres, 433 Mass. 669, 670 (2001). On August 30, 2005, at approximately 9:00 p.m., as part of their routine patrol, Officers Desimone and Chan stopped at the Ocean Lodge in Revere. During the visit, the motel manager, known to them as “Victor,”3 asked the officers to retrieve a discarded hypodermic needle, a service the police regularly provided. As the officers were about to do so, they received a radio dispatch that requested they respond to an emergency call. The officers told Victor that they would return after they responded to the emergency call.
Later that night, around 10:00 p.m., the officers returned to the Ocean Lodge and went to the motel management office to locate Victor. When they did not find him there, the clerk at the desk told the officers that she thought Victor was in his room. The officers thought, based upon past experience, that Victor’s room was room 138; the room was detached from the main building with its own entrance and was a room Victor usually occupied.4
*817Officer Desimone went to room 138, with a container for hazardous objects, while Officer Chan remained in the unmarked cruiser. The officers did not call for assistance because of the routine nature of the transaction. Officer Desimone knocked on the door, announced himself as police, and stated, “Hello, Victor.” An unknown woman opened the door and Officer Desi-mone asked, “Hello, is Victor here?” The woman looked at the officer kind of “funny — like a deer in the headlights type of look” — and stated, “I don’t know.” Desimone showed her the needle holder in his right hand and told her, “He asked me to pick up a needle.” He then asked her, “Can I come in?” to which the woman answered, “Yeah, sure.” Although she appeared to understand the officer’s questions, Desimone testified that she “appeared to be nervous” and “kind of stunned,” as if she were “maybe under the influence of drugs.”
The motion judge found also that “[t]he Commonwealth offered no evidence that the officers believed ‘Victor’ to be married, dating, or living with any women. They did not know who this woman was or what her relationship to Victor or to the room was. She was simply the person who opened the door.”
The woman shut the door after the officer entered. Once inside the room, Officer Desimone realized that the layout for room 138 was different from that of the other rooms in the motel, which usually consisted of only a single room; here, there were two small, adjoining rooms. Upon his entry, immediately after the door closed, and as he stood in the first room with the woman, Officer Desimone noticed to his right, through an open doorway leading to the second room, three men sitting on a bed next to a pile of a green, leafy substance, which appeared to him to be marijuana. The men appeared nervous and started to move their hands around when they saw the officer.
Officer Desimone testified5 that “the last thing [he] wanted to do was make any arrests or bring any type of attention to [the *818motel]” because he did not want to “jeopardize” a major ongoing, unrelated drug investigation at that motel. Officer Desi-mone told the men, “Guys relax. It’s just marijuana. I’m not here to arrest anyone for marijuana.” He then shook the needle canister he was still holding and told them he was here to pick up a needle. Knowing that he was the only officer in a room with four other people, he said, “Guys, just all I’m asking you is to just let me see your hands. I don’t want you guys to shoot me.” The men then looked away from the officer to their right, towards the other end of the room. Officer Desimone could not see what they were looking at because of where he was standing, but he soon heard “some shuffling or scuffling” coming from the room. Still holding the needle holder in his right hand, Officer Desimone stuck his head through the door and heard a “thump” coming from a small metal trash barrel at the far corner of the room. The defendant was standing nervously next to the metal can. Officer Desimone then radioed Officer Chan for assistance.
After Officer Chan and another officer arrived, all the men were relocated to the front room where the woman was still standing. Officer Desimone found a loaded .38 revolver in the trash basket, and the defendant, responding to Officer Desi-mone’s question, admitted that he did not have a firearm identification card for the gun. After retrieving the gun, Officer Desi-mone had a conversation with his superior, Lieutenant Ruggiero, who had just arrived on the scene. Desimone told Ruggiero that he did not want to make an arrest because of the ongoing drug investigation. He recommended putting the gun into safekeeping or doing something that would not involve making an arrest because he “[did not] want to create any type of havoc.” Lieutenant Ruggiero responded “absolutely not,” and insisted on having the defendant arrested. Officer Desimone complied and arrested him.
At 11:00 or 11:30 p.m. that night, Officer Desimone spoke with Victor at the police station. Desimone had wanted to talk *819to Victor to clarify the occupancy of room 138, since he had thought Victor occupied that room. Victor explained that he had not resided in the room for about a week, as he had rented the room to the defendant and the defendant’s father and cousins. The defendant had shown Victor the weapon. Victor told the officer that although he had asked the officer to come to pick up a needle, he really meant to inform the officers of that gun.
The judge allowed the motion to suppress because she found that Officer Desimone unreasonably relied on the woman’s “clear, unambiguous and voluntary” consent. In her findings she stated, “[T]he Commonwealth [did not] establish[] that this woman possessed the actual or apparent authority to consent to the entry.” She found that the officer did not have information suggesting that anyone else was staying in the room with Victor, nor did he have any information about whether Victor was married or dating. She also found that the officers knew nothing about the woman or what, if any, relationship she had with Victor. The motion judge concluded that “there was nothing . . . to suggest a reasonable belief that this woman (who as far as the police knew was simply the person who opened the door) possessed the authority or apparent authority to consent to their entry.”
Discussion. An appellate court accepts the findings of the motion judge in the absence of clear error and defers to his or her assessment of the credibility and weight of testimony. See, e.g., Commonwealth v. Gentile, 437 Mass. 569, 573 (2002); Commonwealth v. Clark, 65 Mass. App. Ct. 39, 43 (2005), and cases cited. However, we must conduct an independent review of the motion judge’s ultimate findings and conclusions of law to assure the correctness of the application of constitutional standards to the facts found. Commonwealth v. Scott, 440 Mass. 642, 646 (2004). Commonwealth v. Wilson, 441 Mass. 390, 393 (2004).
The judge allowed the defendant’s motion to suppress evidence of the gun and drugs because she concluded that the officer unreasonably relied on the consent from the woman who answered the door. This case turns on the issue of apparent authority to consent to an entry by police into a motel room. Fundamental to that question is whether a police encounter of constitutional dimension occurred and, if so, at what moment constitutional import first attached.
*820“Absent express orders from the person in possession against any possible trespass, there is no rule of private or public conduct which makes it illegal per se, or a condemned invasion of the person’s right of privacy, for anyone openly and peaceably, at high noon, to walk up the steps and knock on the front door of any man’s ‘castle’ with the honest intent of asking questions of the occupant thereof — whether the questioner be a pollster, a salesman, or an officer of the law.” Davis v. United States, 327 F.2d 301, 303-304 (9th Cir. 1964) (defendant’s eight year old daughter could consent to police entry, though not search).6 See Manni v. United States, 391 F.2d 922, 923 (1st Cir.), cert. denied, 393 U.S. 873 (1968) (affirming lawfulness of officers’ entry into front room of defendant’s home where “the purpose of the entry was to engage in the conversation the agents had been seeking” and defendant knew of such purpose and consented to entry); Akron v. Harris, 93 Ohio App. 3d 378, 382 (1994) (third party may consent to entry but not to search); State v. Chapman, 97 Ohio App. 3d 687, 690 (1994) (“that where the intent of the officers was not to conduct a search, but only to question a resident, the consent of a third party to enter the house should not be held to the same standard as the consent of a third party to a warrant-less search of the house”); Commonwealth v. Netting, 315 Pa. Super. 236, 240-241 (1983) (evidence not suppressed where guest admitted police to apartment, police were not attempting to secure permission to search apartment but rather were responding to complaint to determine occupants’ well-being, and search was conducted with defendant’s consent). See also United States v. Kim, 27 F.3d 947, 949-950, 954 (3d Cir. 1994), cert. denied, 513 *821U.S. 1110 (1995) (no search or seizure when police questioned defendant at door of sleeping compartment in train). Contrast United States v. Jerez, 108 F.3d 684, 689-693 (7th Cir. 1997) (officer’s continuous knocking on hotel room door around 11:00 p.m. for over three minutes and asking defendant to open door to talk constituted an unconstitutional seizure).7
Here, the officer’s entry into the room was not a search in the constitutional sense; the officer’s purpose in entering the room was neither to search nor arrest, but merely to retrieve the needle that Victor had asked him to pick up.8 The officer did not approach the room intending to search for evidence of criminal activity. See Robbins v. MacKenzie, 364 F.2d 45, 49 (1st Cir.), cert. denied, 385 U.S. 913 (1966) (reasonable for police to rely on householder’s consent to entry when officer disclosed purpose and did not intend to conduct search but only to speak with defendant; officer also did not attempt to engage in search upon entry in home). See also Davis v. United States, 327 F.2d at 303 (officers went to defendant’s home for sole purpose of talking to him and not to search). Contrast Commonwealth v. Painten, 368 F.2d 142, 143-144 (1st Cir. 1966), cert. dismissed, 389 U.S. 560 (1968) (search was likely intended where police sought entry without stating their purpose and where police knew of crime and suspected defendants to be involved). The officer approached the room reasonably thinking Victor was there, and there was no evidence he knew otherwise. The record before us also shows that the officer wanted to avoid any encounters that would lead to arrests because he did not want to interfere with an unrelated, ongoing investigation of the motel. Further, when he saw the *822three occupants sitting on the bed with marijuana, the officer specifically told them that he was not there to arrest them for marijuana. Finally, even after finding the loaded gun, the officer tried to encourage his lieutenant not to arrest the defendant so as not to interfere with the unrelated investigation: his lieutenant insisted on the arrest.
Viewed objectively, these circumstances do not reasonably indicate that Officer Desimone intended to conduct a search, thus obviating any need to second-guess the woman’s consent to enter. The officer, who had no ulterior motive, reasonably relied on her consent after telling her who he was and his purpose. Robbins v. MacKenzie, 364 F.2d at 49 (when officer does not intend to search, officer need not question householder’s consent). Police may rely on a third party’s consent even when they reasonably, though mistakenly, believe she has the authority to consent. Illinois v. Rodriguez, 497 U.S. 177, 186 (1990). See United States v. Rosario, 962 F.2d 733, 737 (7th Cir. 1992) (hotel visitor acted at all times as if he were gatekeeper to room). “The critical facts, however, are not the actual relationship between the consenter and [the occupant-defendant], but how that relationship appears to the officer who asked for consent.” United States v. Jenkins, 92 F.3d 430, 436 (6th Cir. 1996), cert. denied, 520 U.S. 1170 (1997). The totality of the circumstances would not have put a reasonable officer, who was at the room to pick up a dirty needle, on notice that the woman did not have authority to consent to entry into the room. See id. at 436-437; Commonwealth v. Maloney, 399 Mass. 785, 786-788 (1987).
Given the limited purpose of his visit, Officer Desimone acted reasonably in entering without making further inquiry after the woman opened the door, regardless of the fact that he did not know who she was or her relationship with Victor. Here, while the motion judge made findings that the woman “clear[ly], unambiguous [ly] and voluntar [ily] consented]” to the officer’s entry,9 she concluded that the police officer’s reliance on the woman’s consent was not reasonable, given that he did not know *823who the woman was and what relationship, if any, she had with Victor. While we agree with the judge’s finding that the officer did not know who the woman was, we disagree with her conclusion that it was unreasonable for the officer to think she had authority to consent to his entry. Officer Desimone asked her if Victor was there. She said she did not know. The officer then informed her that Victor had asked him to pick up a needle. She said, “Oh, okay.” He asked if he could enter, to which she said, “Yeah, sure.” From this exchange, notwithstanding his lack of knowledge as to whether Victor was married or had a roommate, the police officer had a reasonable belief that the woman had the authority to consent to the officer’s entry into the room. Whether the belief was ultimately erroneous is of no import. Illinois v. Rodriguez, 497 U.S. at 185-186. Georgia v. Randolph, 547 U.S. 103, 109 (2006).
The United States Supreme Court noted in Illinois v. Rodriguez, 497 U.S. at 188, that “law enforcement officers may [not] always accept a person’s invitation to enter premises. Even when the invitation is accompanied by an explicit assertion that the person lives there, the surrounding circumstances could conceivably be such that a reasonable person would doubt its truth and not act upon it without further inquiry.”10 However, here, since the officer expressed no intention to conduct a search (nor can such an intent be reasonably inferred), the attending circumstances were not such that the officer should doubt the woman’s authority to allow his entry.
In this case, Officer Desimone approached the room that he thought Victor was in, and although he did not know the woman who answered the door or her relationship with Victor, she *824never acted as though she could not permit him to enter. See Sterling-Ward v. Tujaka, 414 F. Supp. 2d 727, 735 (E.D. Mich. 2006). Indeed, she was not a child, compare Davis v. United States, 327 F.2d at 502, “[s]he did not hesitate in opening the door, nor did she tell [the officer] she had to check with [the defendant] or anyone else to see if she could let [the officer] in.” Sterling-Ward v. Tujaka, supra. Similarly, here, an objective officer in Desimone’s shoes could reasonably conclude that the woman had authority to allow him to enter, as she asked neither permission nor guidance from anyone in the room before allowing the officer to enter. See United States v. Rosario, 962 F.2d at 737-738 (police reasonably relied on consenter’s apparent authority to permit entry to hotel room when they knocked on door, identified themselves, stated reason they were there, and asked permission to enter room, which consenter immediately provided); Commonwealth v. Hughes, 575 Pa. 447, 461 (2003) (teenage girls sitting on porch outside of house had apparent authority to allow entry when they did not hesitate to give consent and opened door for officers to enter). Here, the woman who allowed the officer to enter answered the door at night, around 10:00 p.m. See United States v. Jenkins, 92 F.3d at 437 (reasonable officer could usually assume that someone who comes to door after police knock has authority to consent to entry). The woman gave no indication that she could not give him permission to enter. The defendant, present at the time, did not object to the officer’s entry. See Commonwealth v. Ocasio, 71 Mass. App. Ct. 304, 307-309, cert. denied, 129 S. Ct. 314 (2008). See also United States v. Rosario, supra. See and compare Georgia v. Randolph, 547 U.S. at 107-108, 120-123. In Commonwealth v. Ocasio, supra, the police reasonably relied on a cotenant’s actual and apparent authority to consent to search the premises even though the defendant was present during the search and never signified assent, nor did he voice any objection or protest to the search. On the record before us, neither the defendant nor any occupant of the second room protested or objected to the woman’s consent to the officer’s entry. Therefore, the officer had no reason to doubt that the woman had authority to give consent. It was thus reasonable for the officer to assume that the woman had authority to allow him to enter to get a needle.
As suggested, the woman gave her consent to Officer Desi-*825mone merely to enter and collect a needle, not to search. Compare Commonwealth v. Noonan, 48 Mass. App. Ct. 356, 362 (1999) (consenter “can surely be taken to have given as much consent as she had power to give”). Indeed, after she agreed to the officer’s entry, she closed the door behind him. Once inside the motel room, Desimone had a clear view of the second bedroom, three occupants sitting on the bed, and a green, leafy substance around them. The officer could lawfully seize the marijuana he saw in plain view on the bed.
Under the plain view doctrine an object may be seized without a warrant when “police are lawfully in a position from which they view an object, if its incriminating character is immediately apparent,” and if they come across the evidence inadvertently. Commonwealth v. D’Amour, 428 Mass. 725, 730-731 (1999). As discussed above, Officer Desimone was lawfully in the motel room when he saw three men sitting on a bed in a second bedroom surrounded by a green, leafy pile. The officer immediately identified the green substance on the bed as marijuana, the incriminating character of which was obvious. Further, the officer inadvertently discovered the contraband, as there is no evidence on the record that the officer anticipated finding any drugs in the room. See Commonwealth v. Balicki, 436 Mass. 1, 8-10 (2002) (upholding inadvertence requirement in art. 14 plain view analysis). Once the officer observed contraband in plain view, he could lawfully seize the evidence, and exigency justified and authorized his securing of the room. Commonwealth v. D’Amour, 428 Mass. at 730-731 (“In the case of contraband and fruits and instrumentalities of crime, the nexus to criminal activity is obvious”). See Commonwealth v. Martino, 412 Mass. 267, 275-276 (1992); Commonwealth v. Gentile, 437 Mass. 569, 575 (2002).
The officer’s seizure of the gun was also proper. Although the woman’s consent was limited to entry, based on articulable facts present here the officer could “perform a limited search of the [motel] room to determine that no one else was present who could have either destroyed the evidence ... or presented] a danger to the officer[] . . . .” Commonwealth v. Streeter, 71 Mass. App. Ct. 430, 439-440 (2008). See Commonwealth v. Fer-rara, 376 Mass. 502, 505 (1978) (if stop of motor vehicle justified, officers could take precautions for own protection). “The *826risk of danger in the context of an arrest in the home is as great as, if not greater than, it is in an on-the-street or roadside investigatory encounter. . . . [U]nlike an encounter on the street or along a highway, an in-home arrest puts the officer at the disadvantage of being on his adversary’s ‘turf.’ An ambush in a confined setting of unknown configuration is more to be feared than it is in open, more familiar surroundings.” Commonwealth v. DeJesus, 70 Mass. App. Ct. 114, 119 (2007), quoting from Maryland v. Buie, 494 U.S. 325, 333 (1990). The Commonwealth must show “articulable facts warranting a belief that there were one or more individuals in the dwelling posing a danger to the police or others present.” Commonwealth v. DeJesus, supra at 116.
Here, Officer Desimone had “articulable facts” to justify the sweep. He saw, in plain view, illegal drugs lying on a bed, the three men sitting on the bed looked extremely nervous, and, when he entered, they started moving their hands around. The men complied with the officer’s request to show their hands and not shoot him, but kept glancing to their right at a part of the room the officer could not see. Finally, the officer heard some movement — shuffling or scuffling — from the room, obviously not coming from the three men on the bed. The officer had reason to believe that someone else was in the room and an “objective concern for [his] safety.” Commonwealth v. DeJesus, supra at 120. See Commonwealth v. Torres, 433 Mass. 669, 675 (2001). As the officer looked into the room, the defendant dropped something into a trash bin that made a thump and that he reasonably could have suspected to be a gun (indeed, as it turned out, it was). As the gun was in plain view and was in reach of the defendant, the officer properly seized the gun.
Consequently, the judge’s order suppressing the marijuana and gun seized from the defendant’s motel room must be reversed.
Order allowing motion to suppress reversed.
Leave to prosecute an interlocutory appeal was allowed by a single justice of the Supreme Judicial Court on March 21, 2007.
The defendant contends that the motion judge was correct in allowing his motion to suppress, relying on the Fourth Amendment to the United States Constitution and art. 14 of the Massachusetts Declaration of Rights. However, the brief does not develop the State constitutional arguments; “[tjhus, we base our views on Federal law only.” Commonwealth v. Waite, 422 Mass. 792, 800 n.6 (1996). See Commonwealth v. D’Onofrio, 396 Mass. 711, 713 n.4 (1986); Commonwealth v. Woods, 419 Mass. 366, 372 n.10 (1995).
“Victor’s” real name was Dipkamur. For the six or seven months that he worked at the motel, he referred to himself as “Victor,” and other officers knew him by that name.
Officer Desimone testified that it was “common knowledge where [Victor] *817stayed.” While the officer had not ever visited Victor in room 138, he visited the motel every night to check the log of occupants at the motel, and Victor often told him “this is where I’m staying,” referring to room 138. The officers had never responded to calls in that room before.
While the judge did not make a specific finding as to the credibility of the officer’s testimony, the defendant did not dispute any of it. Further, the judge used facts from the officer’s testimony as a basis for her opinion, from which *818such a finding is implied. Commonwealth v. Crowe, 21 Mass. App. Ct. 456, 459 n.4, cert. denied sub nom. Pirrotta v. Massachusetts, 479 U.S. 838 (1986) (court concluded that motion judge, who had adopted victim’s facts in findings without specifically determining credibility, had credited her testimony in those respects).
Davis v. United States, supra at 304, discusses the time of police approach as a factor in reasonableness. In Davis, the officers knocked on the defendant’s door in the middle of the afternoon and asked if they could talk to the defendant. The court held that their presence at the door and request to enter and speak with the defendant was not a search and that the defendant’s eight year old daughter, who answered the door, could give consent to the officers’ entry. Id. at 302-305. See State v. Thompson, 578 N.W.2d 734, 740 (Minn. 1998) (“it was reasonable for the officers to believe that the young man who answered the door had the apparent authority to give them limited consent to enter the apartment for the purpose of talking with the occupants therein”). Here, although Officer Desimone approached at approximately 10:00 p.m., the time does not diminish the fact that the officer’s intention was to collect a dirty needle. An hour earlier he had spoken to Victor and had told Victor that he would return after responding to an emergency call.
The dissent sees no need to rely upon extra-jurisdictional case law; however, no cases from this jurisdiction or from the United States Court of Appeals for the First Circuit have been cited or located by us, nor does the dissent rely upon any, that involve a noninvestigatory, nonemergency purpose such as that which brought the police to the defendant’s door.
Under a totality of the circumstances analysis, each case necessarily turns on its facts. Commonwealth v. Rogers, 444 Mass. 234, 242 (2005). 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”). In our analysis of the totality of the circumstances the fact that the police were at the motel to collect a needle, not to conduct a search, supports the propriety of the woman’s consent. Here, one of the facts is unquestionably the reason why the police were at the motel.
The defendant makes the alternative argument, in the event we determine the officer’s reliance on the woman’s grant of permission to enter was reasonable, that the judge erred in her ruling that the woman voluntarily granted permission, contending, rather, that she acquiesced to his authority. We disagree. The consent must be “unfettered by coercion, express or implied, . . . [which *823is] something more than mere ‘acquiescence to a claim of lawful authority.’ ” Commonwealth v. Harmond, 376 Mass. 557, 561 (1978), quoting from Commonwealth v. Walker, 370 Mass. 548, 555, cert. denied, 429 U.S. 943 (1976). Here, the officer’s activities were anything but coercive. The record amply supports the judge’s finding that the woman’s consent was voluntary.
Illinois v. Rodriguez, 497 U.S. at 179-182, 189, presents a different set of facts from here that should prompt officers to be more skeptical of a person’s apparent authority to consent to entry. In Illinois v. Rodriguez, the officers went to the defendant’s apartment to arrest him. They did not have an arrest or search warrant and entered the apartment accompanying a woman who referred to his residence as “our apartment” and who had a key to the front door. The officer in the case before us had no intention to arrest or search upon entry into the hotel room.