456 Mass. 254 (2010)

COMMONWEALTH
v.
PORTER P., a juvenile.

SJC-10383.

Supreme Judicial Court of Massachusetts, Suffolk.

September 10, 2009. March 11, 2010.

Present: MARSHALL, C.J., IRELAND, SPINA, COWIN, CORDY, BOTSFORD, & GANTS, JJ.

*255 James D. Corbo (Rachel A. Scotch with him) for the juvenile.

Kathleen Celio, Assistant District Attorney, for the Commonwealth.

The following submitted briefs for amici curiae:

Beth L. Eisenberg, Committee for Public Counsel Services, & John Reinstein, Joshua Dohan, Barbara T. Kaban, & Gloria Y. Tan for Committee for Public Counsel Services & others.

Ruth A. Bourquin for Massachusetts Coalition for the Homeless & another.

David M. Siegel & Lawrence Friedman for Suffolk Lawyers for Justice, Inc.

GANTS, J.

The Commonwealth was granted leave to appeal from an order entered in the Juvenile Court suppressing a gun seized by the police during a search of a room in a transitional family shelter occupied by the juvenile and a statement that he made after his arrest. Having been notified by the shelter's director that the juvenile allegedly possessed a gun, the police officers determined that the director had the authority to consent to their entry and conducted a warrantless search of the juvenile's room with her consent. After the police found the gun, the juvenile made an unprompted inculpatory statement that suggested that the gun belonged to him. The juvenile was charged with delinquency by reason of the unlawful possession of a firearm and ammunition, in violation of G. L. c. 269, § 10 (h).^[1] After an evidentiary hearing, the judge ordered suppression of the gun and the statement to the police. 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. P. 15 (a) (2), as appearing in 422 Mass. 1501 (1996). The Appeals Court reversed the allowance of the juvenile's *256 motion to suppress. Commonwealth v. Porter P., 73 Mass. App. Ct. 85 (2008). We granted his application for further appellate review. We affirm the allowance of the motion to suppress.^[2]

Background. In reviewing the allowance of a motion to suppress, we accept the judge's findings of fact absent clear error. Commonwealth v. Alvarado, 420 Mass. 542, 544 (1995), and cases cited. We summarize the facts as found by the judge, supplemented by uncontroverted facts in the record. See Commonwealth v. Watson, 430 Mass. 725, 726 n.5 (2000). We then determine "the correctness of the judge's application of constitutional principles to the facts as found." Commonwealth v. Scott, 440 Mass. 642, 646 (2004), quoting Commonwealth v. Mercado, 422 Mass. 367, 369 (1996).

The juvenile and his mother moved into a room at the Roxbury Multi-Service Center, Inc., Family House Shelter (shelter) in March, 2006. The shelter provides temporary housing for otherwise homeless families and assists them in securing more permanent living situations. Through a contractual arrangement with the Commonwealth, the shelter is obligated to accept families referred by the Department of Transitional Assistance if there are vacant rooms of appropriate size to house them. Families may remain at the shelter until they find a permanent living situation, unless they commit a violation of the shelter's rules and regulations. The typical stay is between four and eight months. Apart from a key deposit fee of thirty dollars, the families do not pay to live at the shelter.

Each new resident of the shelter, including the juvenile and his mother, as part of the intake procedure, is given a manual setting forth the shelter's rules and regulations. According to the manual, residents are allowed to have visitors only during posted visiting hours, and may meet with them only in the visitors' lounge.^[3] Residents are not permitted to enter another resident's room at *257 any time for any purpose. Because residents must commit to being actively engaged at least twenty hours per week in employment, education, or job training, or looking for employment or housing, the residents are required to be out of the shelter from 9 A.M. to 3 P.M. every weekday. The residents are also required to abide by a curfew, which varies by the day of the week. Each resident and his or her family is provided a furnished room and given a key to his or her room.^[4] The director, however, has a master key that opens every door in the shelter, and the staff members have a master key that opens every resident's room. Members of the shelter's staff have the right to enter any room "for professional business purposes (maintenance, room inspections, etc.)," but only with the knowledge of the director. If a "business professional," such as a repair person or exterminator, requires entry to a resident's room, he or she must be escorted by a staff member, with the director's approval. The shelter staff may conduct "room checks" at any time without warning to monitor compliance with the shelter's "Good Housekeeping Standard" and other rules and regulations, including those affecting health and safety. The manual has a "zero tolerance policy in regards to violent acts committed by residents" and the possession of any weapon; "[a]ny resident in possession of a weapon will be terminated immediately." The shelter "reserves the right to contact the Police should the situation warrant," but the manual does not state that the shelter director or a staff member may consent to a police search of a resident's room.

On October 25, 2006, the shelter's director, Cynthia M. Brown, after having heard rumors that the juvenile had a gun, learned from a security officer that the juvenile had admitted to having a gun. Brown contacted the Boston police department and arranged a meeting for the following morning "to figure out how [to] proceed."

On October 26, 2006, at approximately 10:30 A.M., Detective Frank McLaughlin and four other police officers met with Brown at the shelter. The officers indicated their desire to "take care of [the situation] quietly" out of "concern for all these families who were ... in a time of turmoil in their own lives." Brown told the officers that the resident's manual authorized her to *258 enter residents' rooms to conduct room checks and that she had inspected residents' rooms several days earlier after reports of suspected drug use. The officers reviewed the portions of the manual authorizing staff to make controlled room entries. Detective McLaughlin confirmed with Brown that her authority to search residents' rooms included the ability to search closets, drawers, bureaus, and other places not in plain view. The detective testified at the evidentiary hearing that he "[a]bsolutely" believed that Brown had the authority to consent to a police search of the juvenile's room. He based this belief on the shelter's rules and regulations in the resident's manual, as well as Brown's possession of a master key to the residents' rooms.

Brown and the officers agreed that they would conduct a search of the juvenile's room "under her policies." They planned to ask the juvenile to relinquish possession of the gun and then, if he cooperated, summons him to court at a later date. They then proceeded upstairs to the room, where Brown knocked on the door and announced that she was conducting a room check. When no one answered, she used her master key to open the door. The juvenile was in the room, and it appeared that he had been lying in bed moments before. Brown explained that she was there to conduct a room check and had the police with her because of allegations that the juvenile had a gun in his possession. Detective McLaughlin asked the juvenile to step out of the room into the hallway, and the juvenile complied. Two or three officers began to search the room while the detective and Brown attempted to speak with the juvenile, who denied having a gun. When Brown asked why he was not in school, he stated that he was home sick that day. During their search of the room, the officers found a Glock .40 caliber firearm containing hollow point bullets in the clip underneath a duffel bag in the closet.

The juvenile was then handcuffed and placed under arrest. Spontaneously, and not in response to any direct questioning by the police, the juvenile said, "The gun has no bodies on it; it's clean." After the juvenile made this statement, an officer read the juvenile the Miranda warnings, but the officers did not initiate questioning.

Discussion. The juvenile argues that the warrantless search of his room at the shelter and the seizure of his firearm violated the Fourth Amendment to the United States Constitution; art. 14 *259 of the Massachusetts Declaration of Rights; and G. L. c. 276, § 1. He also argues that his statement to the police regarding the firearm should be suppressed as "fruit of the poisonous tree" of the illegal search and seizure under Wong Sun v. United States, 371 U.S. 471, 487-488 (1963).

1. To determine whether the search of the room violated the Fourth Amendment; art. 14; or G. L. c. 276, § 1, we must first determine whether a search in the constitutional sense took place. See Commonwealth v. Frazier, 410 Mass. 235, 244 n.3 (1991). "This determination turns on whether the police conduct has intruded on a constitutionally protected reasonable expectation of privacy." Commonwealth v. Montanez, 410 Mass. 290, 301 (1991), citing California v. Ciraolo, 476 U.S. 207, 211 (1986). "The measure of the defendant's expectation of privacy is (1) whether the defendant has manifested a subjective expectation of privacy in the object of the search, and (2) whether society is willing to recognize that expectation as reasonable." Commonwealth v. Montanez, supra. "The defendant bears the burden of establishing both elements." Id. "In examining the expectation of privacy question under art. 14, we do not necessarily reach the same result as under Fourth Amendment analysis." Id.

If no one has a reasonable expectation of privacy in the place searched, the police are free to search that place without a warrant and without probable cause, as often as they wish. See, e.g., California v. Greenwood, 486 U.S. 35, 39-41 (1988) (no reasonable expectation of privacy in garbage left outside curtilage of home); Commonwealth v. Pratt, 407 Mass. 647, 660-661 (1990) (same). If a defendant has a reasonable expectation of privacy, the police may search the place, in the absence of exigency, only with a warrant supported by probable cause or with consent. See Schneckloth v. Bustamonte, 412 U.S. 218, 222 (1973); Commonwealth v. Voisine, 414 Mass. 772, 783 (1993).

Generally, in determining whether a defendant has a reasonable expectation of privacy in the place searched, we look to various factors, none of which needs be determinative, including the nature of the place searched, whether the defendant owned the place, whether he controlled access to it, whether it was freely accessible to others, and whether the defendant took "normal precautions to protect his privacy" in that place. Commonwealth v. Pina, 406 Mass. 540, 545, cert. denied, 498 U.S. *260 832 (1990), and cases cited. These factors may provide guidance when the place searched is not the defendant's home. See Commonwealth v. Bryant, 447 Mass. 494, 497 (2006) (search of files at law firm); Commonwealth v. Welch, 420 Mass. 646, 653-654 (1995) (search of lieutenants' room at fire station); Commonwealth v. Montanez, supra at 301-302 (search of hallway's dropped ceiling); Commonwealth v. Pina, supra at 544-546 (search of wallet left in halfway house where defendant no longer resided).

However, where, as here, the place searched is the interior of the juvenile's home, we need not consult any such factors in deciding that the juvenile has a reasonable expectation of privacy, because the Fourth Amendment and art. 14 expressly provide that every person has the right to be secure against unreasonable searches and seizures in his home. See Fourth Amendment to the United States Constitution ("The right of the people to be secure in their persons, houses, papers and effects, against unreasonable searches and seizures, shall not be violated ..."); art. 14 of the Massachusetts Declaration of Rights ("Every subject has a right to be secure from all unreasonable searches, and seizures, of his person, his houses, his papers, and all his possessions"). "[I]n the case of the search of the interior of homes — the prototypical and hence most commonly litigated area of protected privacy — there is a ready criterion, with roots deep in the common law, of the minimal expectation of privacy that exists, and that is acknowledged to be reasonable" (emphasis in original). Kyllo v. United States, 533 U.S. 27, 34 (2001). See United States v. United States Dist. Court for the E. Dist. of Mich., 407 U.S. 297, 313 (1972) ("physical entry of the home is the chief evil against which the wording of the Fourth Amendment is directed"). In view of the "sanctity of the home," "all details [in the home] are intimate details, because the entire area is held safe from prying government eyes" (emphasis in original). Kyllo v. United States, supra at 37.

The room that the juvenile and his mother shared at the shelter was a transitional living space, but it was nonetheless their home. The juvenile slept and kept his belongings in the room. He and his mother possessed a key to the room, allowing them the degree of privacy inherent in a locked door. The facts that he did not *261 own the room, that he was limited in his use of the room, and that shelter staff members had a master key and could enter the room "for professional business purposes" do not diminish the legitimacy of his privacy interest in the room. The same can be said of a patron of a hotel or a tenant in a boarding house, both of whom enjoy a reasonable expectation of privacy in their rooms. See Stoner v. California, 376 U.S. 483 (1964) (hotel patron); McDonald v. United States, 335 U.S. 451 (1948) (boarding house tenant). Indeed, in Minnesota v. Olson, 495 U.S. 91, 98-100 (1990), the United States Supreme Court made clear that a guest who stays but one night in a friend's home — with or without a key, and with or without paying rent — "has a legitimate expectation of privacy in his host's home." Id. at 98. "That the guest has a host who has ultimate control of the house is not inconsistent with the guest having a legitimate expectation of privacy" in the home. Id. at 99. In short, regardless of whether the juvenile resided in a palatial mansion or a single room in a transitional shelter, regardless of whether he owned the residence or was allowed to remain without paying rent, and regardless of whether his landlord or shelter director had a master key and could enter to ensure that he was abiding by the rules of the house, the juvenile had a reasonable expectation of privacy in his home.^[5],^[6]

*262 2. Because the juvenile had a reasonable expectation of privacy in his room and because the police entered his room without a search warrant and without any claim of exigency, the burden shifts to the Commonwealth to prove that the entry was reasonable because it had the consent of a person with actual or apparent authority over the room. See Illinois v. Rodriguez, 497 U.S. 177, 181 (1990); Commonwealth v. Burgess, 434 Mass. 307, 310 (2001). Here, the juvenile did not consent to the entry, but Brown did, and her consent was "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, 370 Mass. 548, 555, cert. denied, 429 U.S. 943 (1976). The question, then, is whether Brown, as shelter director, had actual or apparent authority to consent to the search of the room.

A third party has actual authority to consent to a warrantless search of a home by the police when the third party shares common authority over the home.^[7] See Georgia v. Randolph, 547 U.S. 103, 106 (2006); United States v. Matlock, 415 U.S. 164, 171 (1974). See also Commonwealth v. Ortiz, 422 Mass. 64, 70 (1996); Commonwealth v. Maloney, 399 Mass. 785, 787-788 (1987). "The authority which justifies the third-party consent does not rest upon the law of property ... but rests rather on mutual use of the property by persons generally having joint access or control for most purposes, so that it is reasonable to recognize that any of the co-inhabitants has the right to permit the inspection in his own right and that the others have assumed the risk that one of their number might permit the common area to be searched." Georgia v. Randolph, supra at 110, quoting United States v. Matlock, supra at 171 n.7.

The reasonableness of a consent search "is in significant part *263 a function of commonly held understanding about the authority that co-inhabitants may exercise in ways that affect each other's interests." Georgia v. Randolph, supra at 111. The Supreme Court has declared:

"It is ... easy to imagine different facts on which, if known, no common authority could sensibly be suspected. A person on the scene who identifies himself, say, as a landlord or a hotel manager calls up no customary understanding of authority to admit guests without the consent of the current occupant.... A tenant in the ordinary course does not take rented premises subject to any formal or informal agreement that the landlord may let visitors into the dwelling, ... and a hotel guest customarily has no reason to expect the manager to allow anyone but his own employees into his room."

Id. at 112, citing Chapman v. United States, 365 U.S. 610, 617 (1961) (landlord could not give valid consent to police to enter space rented to tenant), and Stoner v. California, supra at 489 (hotel clerk was without authority to consent to search of guest's room).

Consequently, common authority does not mean simply the right to enter the premises that the police wish to search. Landlords often contractually retain that right, and hotels routinely do, but that does not allow the landlord or hotel manager to consent to a police search of a defendant's apartment or hotel room. See Chapman v. United States, supra at 616-617 (express covenant may give landlord right of entry to "view waste" but not to permit police to search for contraband); United States v. Jeffers, 342 U.S. 48, 51-52 (1951) (hotel patron gives "implied or express permission [to enter] to such persons as maids, janitors or repairmen in the performance of their duties" but not to police); Commonwealth v. Weiss, 370 Mass. 416, 419 (1976) (locker attendant at Logan Airport may have had authority to conduct private search of defendant's locker, but had no power to authorize police search). We have held that, when a college student executes a residence hall contract that permits college officials to enter the student's dormitory room "to inspect for hazards to health or personal safety," the college officials' authority to enter the room to conduct a health and safety inspection does not entitle those officials to consent to a police search *264 for evidence of a crime. Commonwealth v. Neilson, 423 Mass. 75, 76, 79-80 (1996). Here, the shelter's manual allowed shelter staff to enter the room for "professional business purposes," such as to make repairs, exterminate insects and rodents, and monitor compliance with the shelter's "Good Housekeeping Standard," and to escort "business professionals" into the room to accomplish these purposes, but it did not permit shelter staff to allow the police to enter to search for and seize contraband or evidence.

Therefore, the entitlement of a shelter staff member under the terms of a contract or resident manual to enter a resident's room to search for health or safety risks or violations of house rules, to remove any contraband found during that private search, including firearms and narcotics, and to invite the police to seize that contraband does not entitle that shelter staff member to grant consent to the police to enter the room with her to conduct the search. See id. Cf. Commonwealth v. Leone, 386 Mass. 329, 333 (1982) ("Evidence discovered and seized by private parties is admissible without regard to the methods used, unless State officials have instigated or participated in the search"). The shelter staff member may grant the police such consent only if the resident of the room has agreed in writing that the third party may allow the police to enter to search for contraband or evidence of a crime. See Commonwealth v. Neilson, supra at 79-80.

We understand that the police need clear guidance as to who has common authority over a residence and therefore who is entitled to give actual consent, because, as here, they rely on such consent in deciding to conduct a warrantless search, as opposed to securing the residence and applying for a search warrant.^[8] Therefore, we declare under art. 14 that a person may have *265 actual authority to consent to a warrantless search of a home by the police only if (1) the person is a coinhabitant with a shared right of access to the home, that is, the person lives in the home, either as a member of the family, a roommate, or a houseguest whose stay is of substantial duration and who is given full access to the home; or (2) the person, generally a landlord, shows the police a written contract entitling that person to allow the police to enter the home to search for and seize contraband or evidence.^[9] No such entitlement may reasonably be presumed by custom or oral agreement.^[10],^[11]

*266 Coinhabitancy need not be defined by any legal relationship, such as that of spouses or cotenants on a lease. See Georgia v. Randolph, 547 U.S. 103, 110-111 (2006); United States v. Matlock, 415 U.S. 164, 175-177 (1974) (unmarried person living together in same bedroom with juvenile may consent to search of bedroom). See also Commonwealth v. Martin, 358 Mass. 282, 288 (1970). Rather, it should be defined by the person's demonstrated intent to make a residence his or her home for some substantial period of time. See generally Georgia v. Randolph, supra at 110-112; United States v. Matlock, supra at 171 & n.7. Therefore, an overnight houseguest would lack the authority to consent, unless his or her stay is substantial in its duration, and he or she is given "the run of the house." United States v. Turbyfill, 525 F.2d 57, 58-59 (8th Cir. 1975) (houseguest who had been staying for several weeks and was "occupant of indefinite duration" who "had the run of the house" could consent to police search). See United States v. Clutter, 914 F.2d 775, 777 (6th Cir. 1990), cert. denied, 499 U.S. 947 (1991) ("As a general consideration, there is every reason to suppose that mature family members possess the authority to admit police to look about the family residence, since in common experience family members have the run of the house"); 4 W.R. LaFave, Search and Seizure § 8.5(e), at 235 & n.117 (4th ed. 2004).

Under this standard, Brown did not have actual authority to consent to the police entry into the room to search for a firearm. She was not a coinhabitant of the room, and the shelter manual did not permit her to allow the police to enter the room to search for contraband or evidence. Rather, the manual reserved the right of shelter staff to enter any residential room "for professional business purposes (maintenance, room inspections, etc.)," and to accompany "business professionals" allowed to enter for those purposes. Law enforcement investigation is not reasonably understood to be a "professional business purpose[]." The manual also prohibited weapons of any kind and reserved shelter staff's "right to contact the Police should the situation warrant," but this reservation does not reserve the right to allow the police *267 to enter a resident's room to search for a firearm if accompanied by staff.^[12]

3. Having concluded that Brown did not have actual authority to consent to the search of the room by the police, we turn to whether she had the apparent authority to consent.

In Illinois v. Rodriguez, 497 U.S. 177, 179, 186 (1990) (Rodriguez), the United States Supreme Court held that the Fourth Amendment's proscription of "unreasonable searches and seizures" is not violated when a warrantless entry of a home is based on the consent of a third party who the police, at the time of entry, reasonably, but mistakenly, believed had common authority over the premises. The Court reasoned, "[T]o satisfy the `reasonableness' requirement of the Fourth Amendment, what is generally demanded of the many factual determinations that must regularly be made by agents of the government — whether the magistrate issuing a warrant, the police officer executing a warrant, or the police officer conducting a search or seizure under one of the exceptions to the warrant requirement — is not that they always be correct, but that they always be reasonable." Id. at 185-186. The Court concluded that "[t]he Constitution is no more violated when officers enter without a warrant because they reasonably (though erroneously) believe that the person who has consented to their entry is a resident of the premises, than it is violated when they enter without a warrant because they reasonably (though erroneously) believe they are in pursuit of a violent felon who is about to escape." Id. at 186. Apparent authority is "judged against an objective standard: would the facts available to the officer at the moment ... `warrant a man of reasonable caution in the belief' that the consenting party had authority over the premises?" Id. at 188, quoting Terry v. Ohio, 392 U.S. 1, 21-22 (1968).

Federal courts have universally limited apparent authority to reasonable mistakes of fact, not mistakes of law. See, e.g., United States v. Ruiz, 428 F.3d 877, 882 (9th Cir. 2005); United States v. Davis, 332 F.3d 1163, 1170 (9th Cir. 2003); United States v. Gutierrez-Hermosillo, 142 F.3d 1225, 1230 (10th Cir.), *268 cert. denied, 525 U.S. 900 (1998); United States v. Brazel, 102 F.3d 1120, 1148 (11th Cir.), cert. denied, 522 U.S. 822 (1997); United States v. Brown, 961 F.2d 1039, 1041 (2d Cir. 1992); United States v. Salinas-Cano, 959 F.2d 861, 865 (10th Cir. 1992); United States v. Whitfield, 939 F.2d 1071, 1073-1074 (D.C. Cir. 1991). The Rodriguez decision "thus applies to situations in which an officer would have had valid consent to search if the facts were as he reasonably believed them to be." United States v. Whitfield, supra at 1074. "An officer's mistaken belief as to the law, even if reasonable, cannot establish apparent authority." United States v. Davis, supra at 1170. See United States v. Elliott, 50 F.3d 180, 186 (2d Cir. 1995), cert. denied, 516 U.S. 1050 (1996) (Rodriguez "validates only searches that are based on a reasonable mistake as to the facts, not those based on an erroneous legal conclusion drawn from the known facts"). See generally 4 W.R. LaFave, Search and Seizure, supra at § 8.3(g), at 175 & n.126.

The police officers' mistake in this case was one of law, not of fact. Detective McLaughlin and the other officers took considerable care to ascertain whether Brown had the authority to consent to a search of the room. Prior to entering the room, Detective McLaughlin conferred with Brown and reviewed the portions of the manual pertaining to staff searches of the rooms. They accurately understood the relevant facts regarding Brown's authority to consent to the search. They erred not in their understanding of the facts or in the diligence of their inquiry into Brown's authority to consent to the search, but in their understanding of the law; they believed that these facts gave them valid consent to search the room when, as a matter of law, they did not.^[13] Because *269 Brown did not have actual or apparent authority to consent to the search, the warrantless search of the room was not reasonable under the Fourth Amendment or art. 14.

4. Having concluded that the officers' search of the room was unconstitutional under the Fourth Amendment and art. 14, we need not decide under art. 14 whether a warrantless search of a home may be justified by apparent authority. We choose to decide this issue because (1) the issue, at our request, has been fully briefed, (2) our earlier decisions have suggested, but not decided, that art. 14 adopts the doctrine of apparent authority, see infra, and (3) our trial courts are already obliged to apply this doctrine, because the Appeals Court has recently approved of a consent search based solely on apparent authority. See Commonwealth v. Dejarnette, 75 Mass. App. Ct. 88, 95-96 (2009).

Even before the United States Supreme Court decided Rodriguez, supra, we suggested that apparent authority may justify a warrantless search where the person giving consent lacks actual authority, but we have never approved a warrantless search exclusively on apparent authority. See Commonwealth v. Maloney, 399 Mass. 785, 787-788 (1987) (holding that live-in boy friend of defendant's sister could consent to police search because he "appeared to be a lawful occupant with authority to permit the police to enter," while simultaneously recognizing actual authority of sister, who was also present, to consent); Commonwealth v. Wahlstrom, 375 Mass. 115, 118 (1978) (holding that employee of store had "sufficient appearance of authority" to consent to police search but deciding case on basis of common, or actual, authority). See also Commonwealth v. Rogers, 444 Mass. 234, 248-249 (2005) (Greaney, J., dissenting) (officer's entry justified by apparent authority, in addition to actual authority); Commonwealth v. Lopez, 74 Mass. App. Ct. 815, 831 n.4 (Lenk, J., dissenting), further appellate review granted, 455 Mass. 1103 (2009) ("To date, no warrantless police entry has been upheld in Massachusetts solely on the basis of apparent authority to consent ..."). Consistent with these past decisions but for the first time today, we explicitly adopt under art. 14 the doctrine of apparent authority.

"The right of police officers to enter into a home, for whatever purpose, represents a serious governmental intrusion into one's privacy." Commonwealth v. Peters, 453 Mass. 818, 819 (2009), *270 quoting Commonwealth v. DeJesus, 439 Mass. 616, 619 (2003). In general, art. 14 allows the police to enter a home in four circumstances: (1) a judicial warrant supported by probable cause, Commonwealth v. Anderson, 406 Mass. 343, 346 (1989); (2) probable cause plus exigency, such as hot pursuit of a violent suspect trying to escape, Commonwealth v. Paniaqua, 413 Mass. 796, 798 (1992); (3) under the "emergency aid" doctrine, where the police have "an objectively reasonable basis to believe that there may be someone inside who is injured or in imminent danger of physical harm," Commonwealth v. Peters, supra at 819; and (4) the voluntary consent of a person with common authority over the home, supra at 264-265.

In each of the first three circumstances, art. 14 is not violated by reasonable mistakes of fact. We evaluate the reasonableness of a police officer's conduct based on the information available to him at the time, not on what we later learn to be true. Commonwealth v. Young, 382 Mass. 448, 456 (1981) ("whether the response of the police was reasonable and therefore lawful [is] to be evaluated in relation to the scene as it could appear to the officers at the time, not as it may seem to a scholar after the event with the benefit of leisured retrospective analysis"). If probable cause in a search warrant affidavit is based on information from a reliable source with personal knowledge, we do not conclude that there has been a violation of art. 14 if the information turns out to be inaccurate, provided the affiant did not know the information to be false or show reckless disregard for its truthfulness. Commonwealth v. Wilkerson, 436 Mass. 137, 140-142 (2002), quoting Commonwealth v. Storey, 378 Mass. 312, 321 (1979), cert. denied, 446 U.S. 955 (1980) ("existence of probable cause is determined `at the moment of arrest,' not in light of subsequent events"). If a police officer has probable cause to believe that a suspect has just committed a violent crime and reason to believe that he fled into an apartment, and if there is not time to obtain a warrant because of exigent circumstances, we do not conclude t