Around midday on December 7, 2004, three uniformed police officers entered the fenced-in backyard of a private home in a residential neighborhood of Portland. Guns drawn, but without a warrant, one scaled the fence and another kicked open a padlocked gate leading into the backyard. The only information the officers had at that time was (1) a call from a neighbor reporting that the owners were at work and that a white male wearing a black jacket, age unknown, had thrown a red backpack over the fence and climbed into the backyard; and (2) their visual confirmation that a red backpack was lying against a porch in the backyard and that the person they saw in the yard, who turned out to be the appellant, Rian Struckman, was a white male wearing a black jacket, which he allowed to fall to the ground after being confronted by the officers. The officers’ first statements to Struckman were to order him to get down on the ground. Struckman’s first statement to the officers was that he lived at the house. As it turned out, he did, but the officers only found that out after Struckman was arrested and after they had searched the backpack, finding an unloaded handgun. By that point, the officers had also learned that Struckman was a former felon, however, and arrested him as a felon in possession of a firearm in violation of 18 U.S.C. § 922(g)(1). He was ultimately found guilty in a jury trial of that crime and sentenced to 17 years in prison.
Struckman appeals the district court’s denial of his motions to suppress and his sentence. We conclude that the police officers’ warrantless actions violated Struck-man’s Fourth Amendment rights. We therefore reverse the district court’s order denying Struckman’s motion to suppress the handgun found in the backpack and, because the gun was critical to Struck-man’s conviction, vacate the resulting conviction.
*736 I. Background
On December 7, 2004, at approximately 11:45 a.m., Wendy Grimes called 911 and reported that she saw a white male wearing a black leather o'r vinyl jacket throw a red backpack over ■ her neighbors’ fence and then climb over the fence into their backyard. Ms. Grimes also stated that her neighbors were not at home and, although she indicated a suspicion the man was trying to break into her neighbors’ house, she also said she could not see what he was dоing through her neighbors’ fence.
The dispatcher sent three police officers to investigate the report, directing them to the home and telling them only that “[a] white male climbed the fence on the west side. White guy, black leather jacket, red backpack. Residents not there at this point.”
Officers Mudrick and Wilson arrived at the house first. Officer Mudrick approached a padlocked gate leading into the backyard on the east side of the house. Officer Wilson approached the west side of the house. The backyard was entirely enclosed by a six foot tall fence. Officer Mudrick climbed atop an object positioned next to the gate to get a better view while Officer Wilson peeked into the yard through a small hole in the fencе.
Officer Wilson saw Struckman, who fit the description of the person given by the 911 dispatcher — “[wjhite guy, black leather jacket” — walking inside the backyard. He also saw a red backpack lying next to a deck in the yard. At this same time, on the other side of the house, Officer Mudrick saw Struckman walk around the back of the house in his direction. He saw no signs of any forced entry into the house. As Struckman turned the corner, he noticed Officer Mudrick -staring at him from over the top of the fence. With a look of surprise, he stopped walking.
The following events took place over a span of roughly 25 seconds: Officer Mudrick testified that once Struckman saw him, he immediately “took off his jacket ... and let it fall to the ground.” Officer Wilson’s testimony was slightly different: Struckman “shook” his “leather jacket off his shoulders”; it “just sort of fell down his arms.” Officer Wilson also testified that Struckman’s hands remained “down by ... his thighs ... as [his] jacket dropped down.” Both officers testified that Struckman did not attempt to run and had nothing on him at that point other than his shirt and pants. In particular, he had no visible weapons or burglary tools.
Officer Mudrick drew his firearm and pointed it at Struckman straightaway, ordering him to get down on his knees. Struckman complied without hesitation. Officer Mudrick then reholstered his firearm and climbed over the fence into the backyard. During this time, Officer Wilson, who had also drawn his firearm, moved to the east side of the house. Officer Mudrick, who was now inside the yard, drew his firearm again, approached Struckman, and began to handcuff him. At this time, Officer Singh arrived at the house and immediately kicked open the padlocked gate leading into the backyard. Both he and Officer Wilson then entered the backyard to help Officer Mudrick finish handcuffing Struckman and search the area. 1
According to Officers Mudrick’s and Wilson’s testimony, 2 after Officer Mudrick *737 climbed into the backyard, Struckman began cursing sporadically and repeatedly stated that he lived at the house. 3 Struck-man also requested that Officer Mudrick use his cell phone to call his mother to confirm that he lived at the house. Officer Mudrick ignored Struckman’s request, however, and proceeded to conduct a pat down search. During this time, Struck-man’s behavior alternated between cooperative and aggressive; on one or two occasions Struckman tried to pull away from Officer Mudrick’s grip. 4 As a result, Officer Mudrick forced Struckman to the ground to complete the pat down search, at which time he felt a long, hard object in Struckman’s front right pants pocket. He opened the pocket and discovered an unloaded handgun magazine. Officer Mudrick then completed the search and asked Struckman whether there was a gun inside the red backpack, which was lying approximately 20 to 25 feet away at this time. Officer Mudrick testified, and the district court found, that Struckman replied, “I don’t know, it’s not mine.” Struckman, on the other hand, testified at trial that he also stated, “It’s my sister’s bag.”
After Officer Mudrick discovered the unloaded magazine, Officer Wilson went to the red backpack and lifted a flap that was on the top of it. He saw the butt of a handgun and retrieved the gun from the backpack. There was no magazine in the gun.
Officer Mudrick eventually аsked Struckman his name. Struckman gave his true name and stated that he was currently on probation. Officer Mudrick then ran a criminal history check, revealing that Struckman was on probation and did in fact live at the house.
After he was indicted on one count of being a felon in possession of a firearm in violation of 18 U.S.C. § 922(g)(1), Struck-man moved to suppress the handgun found in the backpack, arguing that the officers’ warrantless arrest and entry, and their subsequent search of the backpack, violated his Fourth Amendment rights. 5 The district court held an evidentiary hearing on the suppression motion and denied it.
The government filed a Notice of Sentence Enhancement under the Armed Career Criminal Act, 18 U.S.C. § 924(e)(1). 6 Following a jury trial, Struckman was found guilty of being a felon in possession of a firearm, and sеntenced to 17 years in prison.
II. Discussion
The Fourth Amendment protects “[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and sei
*738
zures.... ” U.S. Const. amend. IV. “At [its] very core stands the right of a [person] to retreat into his own home and there be free from unreasonable governmental intrusion.”
Silverman v. United States,
This presumptive Fourth Amendment protection “is not irrebuttable.”
Hopkins v. Bonvicino,
The “emergency” exception stems from the police officers’ “community caretaking function” and allows them “to respond to emergency situations” that threaten life or limb; this exception does “not [derive from] police officers’ function as criminal investigators.” United States v. Cervantes,219 F.3d 882 , 889 (9th Cir.2000) (emphasis added). By contrast, the “exigency” exception does derive from the police officers’ investigatory function; it allows them to enter a home without a warrant if they have both probable сause to believe that a crime has been or is being committed and a reasonable belief that their entry is “necessary to prevent ... the destruction of relevant evidence, the escape of the suspect, or some other consequence improperly frustrating legitimate law enforcement efforts.” United States v. McConney,728 F.2d 1195 , 1199 (9th Cir. 1984) (en banc).
Hopkins,
Before evaluating whether there were exigent circumstances, we note that the district court upheld the officers’ warrantless search and seizure under
Terry v. Ohio,
As a result of its
Terry
approach, the district court did not decide whether Struckman’s backyard is curtilage subject to Fourth Amendment protection. That, however, is an issue we may decide de novo on the record before us.
United States v. Davis,
A.
The Fourth Amendment’s protections extend to those areas in which a person has a “reasonable” expectation of privacy,
Smith v. Maryland,
“[F]or most homes, the boundaries of the curtilage will be clearly marked; and the conception defining the curtilage — as the area around the home to which the activity of home life extends — is a familiar one easily understood from our daily experience.”
Oliver,
B.
The government asserts that probable cause alone justifies Struckman’s warrant-less arrest and the police officers’ subsequent entry into his backyard. That is plainly incorrect. “It is clearly established Federal law that the warrantless search of a dwelling must be supported by probable cause and the existence of exigent circumstances.”
Bailey v. Newland,
The government also asserts, alternatively, that exigent circumstances excused the officers’ warrantless arrest and entry. “[W]hen the government relies on the exigent circumstances exception [to the Fourth Amendment warrant requirement], it ... must satisfy two requirements: first, the government must prove that the officer had probable cause to search the house; and second, the government must prove that exigent circumstances justified the warrantless intrusion.”
United States v. Johnson,
1.
“There is probable cause for a warrantless arrest and a search incident to that arrest if, under the totality of the facts and circumstances known to the arresting officer, a prudent person would have concluded that there was a fair probability that the suspect had committed a crime.”
United States v. Gonzales,
Relying on the 911 report, the officers’ initial sighting of Struckman, and Struck-man’s reaction to seeing Officer Mudrick, the government asserts that thе officers had probable cause to arrest Struckman for either burglary in the first degree, attempted burglary in the first degree, or criminal trespass in the second degree. The government also relies on Officer Mudrick’s testimony that he believed, based on the 911 report, that he was investigating a burglary or attempted burglary.
Officer Mudrick’s subjective beliefs are immaterial to our inquiry: “Probable cause is an objective standard[,] and the officer’s subjective intention in exercising his discretion to arrest is immaterial in judging whether his actions were reasonable for Fourth Amendment purposes.”
John v. City of El Monte,
We have little difficulty concluding that the officers did not have probable cause to arrest Struckman for first-degree burglary or attempted burglary. Under Oregon law,
[a] person commits the crime of burglary in the first degree if the person violates 0[r.] R[ev.] S[tat.] [§ ] 164.215 and the building is a dwelling, or if in effecting entry or while in a building or in immediate flight therefrom the person: (a) Is armed with a burglary tool or theft device ... or a deadly weapon; (b) Causes or attempts to cause physical injury to any person; or (c) Uses or threatens to use a dangerous weapon.
Or.Rev.Stat. § 164.225(1). A person violates Or.Rev.Stat. § 164.215, Oregon’s second-degree burglary statute, “if the person enters or remains unlawfully in a building with intent to commit a crime therein.” In addition, a person is guilty of an attempt to commit a crime in Oregon if the person “intentionally engages in conduct which constitutes a substantial step toward commission of the crime.” Or.Rev.Stat. § 161.405(1).
Here, it is undisputed that upon arriving at the house, the officers knew only thаt a neighbor had reported seeing a white male wearing a black jacket throw a red backpack over a fence and climb over the fence into the backyard when the owners were reportedly not home. Officer Mudrick testified that there were no indications that Struckman had entered or attempted to enter the home, as there were no signs of forced entry or the presence of any tools consistent with a possible burglary. Additionally, Struckman’s presence in the backyard and his reaction to abruptly seeing Officer Mudrick, unannounced and peering over his six-foot tall fence — stopping, looking surprised, and shrugging off or allowing his jacket to fall to the ground' — have no bearing on whether Struckman was attempting a burglary at the homе. 7
*741
The conclusion that the officers certainly did not have probable cause to believe that Struckman was engaged in first-degree burglary or attempted burglary does not end our inquiry, however. “Because the probable cause standard is objective, probable cause supports an arrest so long as the arresting officers had probable cause to arrest the suspect for any criminal offense, regardless of their stated reason for the arrest.”
Edgerly v. City and County of San Francisco,
A person commits criminal trеspass in the second degree in Oregon if he “enters or remains unlawfully ... in or upon premises,” Or.Rev.Stat. § 164.245(1), where premises are defined as “including] any building and any real property, whether privately or publically owned,” Or.Rev. Stat. § 164.205(6). A person enters or remains unlawfully if he or she “enter[s] or remain[s] in or upon premises when the premises, at the time of such entry or remaining, are not open to the public or when the entrant is not otherwise licensed or privileged to do so[.]” Or.Rev.Stat. § 164.205(3)(a).
Here, the officers came to the house because of information obtained from the 911 call — namely, that a white male wearing a black jacket had thrown a red backpack over a fence and climbed into the backyard when the homeowners were reportedly not home. They then visually confirmed that a person who fit the description was in the backyard and that there was a red backpack lying against a deck inside the yard.
8
To that point, the officers were engaging in good police practice. Assuredly, “police officers ha[ve] a duty to conduct an investigation into the basis of [a] witness’ report.”
Fuller v. M.G. Jewelry,
*742 At the same time, Ms. Grimes’s report was very general; she did not say that she knew who all the occupants of the house were; and innocent reasons could have explained what she did see, including the actual explanation — a family member who lived at the house did not have his key. Indeed, many of us can recount tales about getting locked out of his or her own house, or the house of a relative where one is staying, and having to devise some creative way to get into the house.
To avoid such errors as occurred here, in seeking to establish probable cause, “officers may not solely rely on the claim of a citizen witness ..., but must independently investigate the basis of the witness’ knowledge or interview other witnesses.”
Arpin v. Santa Clara Valley Transp. Agency,
As in
Frunz
and
Hopkins,
“[t]here was, in fact, much else the officers could have done” to investigate the reported activity.
Frunz,
More importantly, the officers could have asked Struckman a few simple questions, such as “What’s your name?” “Do you live here?” “What are you doing in the backyard?” Instead, immediately after first making eye contact with Struck-man, Officer Mudrick drew his firearm and ordered Struckman to get on the ground, and the officers surged into the backyard, with one officer chmbing over the fence and another kicking open the padlocked gate. The officers then ignored Struekman’s repeated protestations that he lived at the house and his request that the officers call his mother to confirm his statement, even though they could have learned that he did in fact live there by checking his identification against records easily available to them. 11
*743
The officers did have reasonable suspicion — a “reasonable, articulable suspicion that criminal activity is afoot,”
Illinois v. Wardlow,
Nonetheless, no amount of probable cause can justify a warrantless arrest or entry absent an exception to the warrant requirement.
See Horton v. California,
2.
As previously mentioned, the government relies on the exigency exception, as opposed to the emergency exception, to justify the officers’ warrantless actions here. The exigent circumstances exception is premised on “few in number and carefully delineated” circumstances,
United States v. United States District Court,
The government suggests that this case involved the exigent circumstances of hot pursuit, escape, and the prevention of harm to the officers or other persons. 12 *744 None of these circumstances actually existed when Struckman was arrested in the backyard.
First, “ ‘hot pursuit’ means some sort of a chase.”
Santana,
Likewise, contrary to the government’s suggestion that the general public was in danger, the record contains no evidence that anyone other than the officers and Struckman was near the fully enclosed backyard, let alone put in danger by the occurrences therein. Nor was the police officers’ entry into the backyard necessary to prevent harm to themselves. The government points to Struckman’s reaction upon seeing the officers as suggesting some element of danger — he looked surprised and took off his jacket. Again, anyone, residents included, would be surprised at seeing a uniformed police officer peering at them inside their private, enclosed backyard from over the top of a six-foot fence. Surprise does not suggest a threat.
Even if Struckman intentionally took off his jacket after seeing Officer Mudrick — a point on which the record is murky — that conduct, peculiar as it may have seemed to the officers at that time, does not support an objectively reasonable basis for believing that the police officers’ reaction — immediately drawing their firearms and entering the enclosed backyard — was necessary to prevent imminent physical harm to themselves while they remained outside the yard. In fact, Officer Mudrick testified that after Struck-man’s jacket fell to the ground, he was able to see Struckman’s body clearly and saw no visible weapons on him. Additionally, Officer Wilson testified that Struck-man’s arms remained down at his sides after he shed his jacket.
In support of its contention that the exigency exception is applicable here, the government relies heavily on Officer Mudrick’s testimony that once Struckman shed his jacket, he
believed
that Struck-man
intended
to flee or fight the officers free of an encumbrance. As previously discussed, however, an officer’s subjective motivation for his actions is irrelevant in determining whether his actions are reasonable under the Fourth Amendment.
See, e.g., Brigham City,
Moreover, Officer Mudrick’s belief that Struckman’s shedding of his jacket meant that he was preparing to fight the officers
*745
assumes an intent to enter Struckman’s yard, but does not explain or justify it. And there is an additional consideration here that strongly supports the conclusion that there was no exigenсy: Although “[a] warrantless arrest of an individual in a
public
place for ... a misdemeanor committed in the officer’s presence[ ] is consistent with the Fourth Amendment if the arrest is supported by probable cause,”
Maryland v. Pringle,
Here, even if the police officers had probable cause to believe that Struck-man was committing criminal trespass in the second degree in violation of Or.Rev. Stat. § 164.245, the offense is a Class C misdemeanor,
see id.,
carrying with it a maximum of 30 days imprisonment, Or. Rev.Stat. § 161.615. And, while we recognize that “the exigency analysis must turn on ‘the
gravity
of the underlying offense,’ ... not its status as ‘jailale’ or ‘nonjailable,’ ”
Hopkins,
In addition, while the commission of a misdemeanor offense is not to be taken lightly, it militates against a finding of exigent circumstances where the offense, like the criminal trespass at issue here, is not inherently dangerous. We have held, for example, that police officers violate tenants’ Fourth Amendment rights if they enter the tenants’ аpartment without a warrant based solely on the landlord’s report that the tenants were trespassing.
See King v. Massarweh,
In a case closely analogous to this one, the Sixth Circuit concluded that “[t]here is simply no legal support for holding that an ongoing criminal trespass, on its own, constitutes an exigency that overrides the warrant requirement.”
United States v. Washington,
Finally, there is the consideration here that even if the officers had probable cause to believe that Struckman was trespassing when they first saw him — which, as we said, we doubt but are willing to assume for present purposes — -that probable cause could easily have been dissipated by minimal inquiry at the outset, before the officers entered the backyard and searched and questioned Struckman.
Cf. Radvansky v. City of Olmsted Falls,
For all these reasons, “[i]f we were to permit a warrantless ... [arrest and] entry under these circumstances, which were not urgent or life threatening, the effect would certainly undercut making ‘the presumption of unreasonableness ... diffiсult to rebut,’ ”
Washington,
C.
We emphasize that “Fourth Amendment rights are personal rights which, like some other constitutional rights, may not be vicariously asserted.”
Alderman v. United States,
III. Conclusion
The police officers’ warrantless seizure of Struekman within his backyard and their entry into the yard to perfect his arrest, violated the Fourth Amendment. 14 We therefore reverse the district court’s denial of the suppression motion. As the introduction of the evidence obtained as a result of the officers’ warrantless actions was critical to Struckman’s conviction, and the government does not contend that any error in failing to suppress it was harmless, we also vacate the judgment of the conviction.
REVERSED and VACATED.
Notes
. At some point, one of the officers informed the dispatch: "Got a gun on that guy. Burglar.”
. Neither Struckman nor Officer Singh testified at the suppression hearing.
. The district court found that Struckman stated that he lived at the house before Officer Mudrick climbed over the fence. That finding is not supported by the record, however, as both Officers Mudrick and Wilson testified that Struckman did not state that he lived at the house until after Officer Mudrick was inside the backyard.
. Struckman testified at trial that he was high on methamphetamine at this time.
. Struckman subsequently moved to suppress the statement he made in the backyard concerning the backpack, arguing that the police officers failed to issue Miranda warnings. Because we conclude that the officers’ warrantless arrest and entry violated Struckman's Fourth Amendment rights, we do not reach the Miranda issue.
. 18 U.S.C. § 924(e)(1) provides, in pertinent part, that "[i]n the case of a person who violates section 922(g) of this title and has three previous convictions by any court referred to in section 922(g)(1) of this title for a violent felony or a serious drug offense, or both, committed on occasions different from one another, such person shall be fined under this title and imprisoned not less than fifteen years....”
. It is unclear why Struckman shrugged off his jacket. He may have done so because his jacket pockets contained methamphetamine, a "digital gram scale/' and a second unloaded gun magazine. Or, as Officer Mudrick testified, Struckman may have shrugged off his jacket in order to fight or flеe, free of an encumbrance. Or, as Struckman testified at trial, he may have simply "slipped his arm out of [his jacket]'' because "with the way that
*741
[his] jacket was [hanging off one arm at the time], when [he] went to go put up [his] arms, [he] thought it might create an obstruction.” In any event, Struckman’s intention does not matter. Our inquiry is limited to determining whether the objective facts and circumstances before the officer are sufficient to warrant a person of reasonable caution to believe that there was a fair probability that the suspect had committed a crime.
Gonzales,
. Once again, the government brings up Struckman’s surprised expression upon seeing Officer Mudrick peering at him from over the top of his six-foot tall fence, arguing that it supports probable cause that Struсkman was trespassing in the backyard. That fact, regardless whether one views it as innocuous or suspicious with regard to possible exigency, has little to do with whether Struckman ’’enter[ed] or[was] remaining] unlawfully” on someone else's property in violation of Or. Rev.Stat. § 164.245. Indeed, one would think almost any resident of a house would be quite surprised to see a policeman peering at him over his fence while he was in his backyard. Likewise, as to Struckman’s shrugging off or discarding his jacket, whether or not it is pertinent to the exigency issue, see infra, it in no way supports the conclusion that Struck-man had no legal right to be where he was.
. We note that in Oregon a person may be criminally liable for knowingly initiating and transmitting a false report to the police. See Or.Rev.Stat. § 162.375.
. The 911 transcript indicates that Ms. Grimes initially reported the wrong address and pointed out the correct one to at least one of the officers after he had arrived in the area.
. Officer Mudrick testified at the suppression hearing that the officers on the scene had computers in their patrol cars and radios attached to their uniforms that they could have used to call dispatch to determine whether Struckman lived at the house.
. The government does not defend the district court’s determination that the 911 call alone created exigent circumstances because the police officers were responding to a potential burglary in progress. As previously discussed, the officers, were not responding to a report of a potential burglary in progress, only a repоrt that a white male wearing a black jacket and carrying a red backpack had climbed over a fence into the backyard of a home while the homeowners were not there. Although Ms. Grimes told the 911 dispatcher that she suspected that the person was going to commit a burglary, she could not see into the yard to confirm that suspicion, and the *744 dispatcher did not relay that speculative presumption to the officers.
. By contrast, where there is probable cause to suspect a burglary, police officers "have no idea who might be inside [the home] and may reasonably assume that the suspects will, if confronted, flee or offer armed resistance."
Frunz,
. Because we conclude that the police officers' warrantless arrest and entry violated Struckman’s Fourth Amendment rights, we need not reach the other issues raised on appeal.
