OPINION
¶ 1 After a bench trial, the trial court found appellant Tony Dewayne Smith guilty of possessmg a deadly weapon as a proMbited possessor in violation of A.R.S. § 13-3102 and sentenced him to a presumptive term of 4.5 years m prison. On appeal, Smith contends the trial court erred in denying his motion to suppress the handgun, assertmg that law enforcement officers unlawfully entered his home and conducted a search. We conclude the trial court failed to apply the correct standard in determinmg whether the officers had lawfully entered Smith’s residence, and we remand the case to permit a redetermination of the issue under the proper standard.
BACKGROUND
¶2 We view the evidence presented at the suppression hearing and the reasonable inferences therefrom m the light most favorable to upholdmg the ruhng.
State v. Rodriguez,
¶3 While Heath pursued Smith, Murphy handcuffed and interviewed three people who were standmg in the area of Smith’s trailer. 1 *22 Sergeant Murphy then joined the search for Smith. The officers pursued Smith on foot separately for about forty-five minutes, leaving their patrol cars at his trailer. Deputy Heath testified that he had followed footprints in a sandy wash that began in the same location where the drag marks ended. He followed the footprints for about one hundred fifty yards before losing them after the tracks circled back toward the area of the trailer. Unable to locate Smith in the desert, the officers returned to his trailer, knocked on the door, and announced their presence. When they received no response, they entered the trailer and found the prohibited weapon and other contraband.
¶ 4 According to Heath, the general direction of the last visible footprints, coupled with the fact that Murphy had not been watching the trailer the entire time, had caused the officers to enter the trailer to “make sure Smith had not re-entered” it. According to Murphy, the officers had entered the trailer because they had believed Smith “may have circled back” and, therefore, had “reason to believe he may have” returned to the trailer.
¶ 5 Smith moved to suppress the evidence, arguing that the officers could not lawfully enter his residence, even though they possessed an arrest warrant, without probable cause to believe he was within the trailer. Smith asserted they had lacked such cause. In a terse ruling, the trial judge denied Smith’s motion, stating: “The deputies had a valid arrest warrant for the Defendant and they believed he may have returned to his trailer home. Therefore, their entry was lawful.” The court did not provide any further factual findings or conclusions of law. Smith now challenges that ruling.
DISCUSSION
¶ 6 In reviewing the denial of a motion to suppress evidence, we defer to the trial court’s factual determinations, but the ultimate ruling is a conclusion of law we review
de novo. State v. Gonzalez-Gutierrez,
¶ 7 Here, the officers had a valid warrant to arrest Smith but not to search his home. However, “an arrest warrant founded on probable cause implicitly carries with it the limited authority to enter a dwelling in which the suspect lives
when there is reason to believe the suspect is within.” Payton v. New York,
*23 ¶ 8 The state counters that, once in possession of an arrest warrant, the officers needed only a reason to believe that Smith “might be hiding inside” to lawfully enter his trailer. (Emphasis added.) In so doing, the state endorses the trial court’s implied conclusion that the mere possibility of officers finding a suspect within his or her residence should be adequate to authorize the officers’ entry when they possess an arrest warrant. See The Oxford Dictionary and Thesaurus 946 (Am. ed.1996) (defining “might” or “may” as “expressing possibility”).
¶ 9 Although numerous state and federal appellate courts have addressed what level of cause officers must have to satisfy the reason-to-believe standard set forth in
Payton,
the United States Supreme Court has not amplified its analysis of the question.
See
3 Wayne R. LaFave,
Search and Seizure
§ 6.1(a), at 226 (3d ed. 1996) (“Just what [the reason-to-believe standard] means continues to be a matter of considerable uncertainty.”);
see also United States v. Magluta,
¶ 10 Thus, neither the United States Supreme Court nor any Arizona court has squarely addressed the primary question presented by the trial court’s order in this ease: whether officers possess a reason to believe that a suspect is within his or her residence when circumstances suggest that the suspect “may” be found there, or whether that belief must be based instead on circumstances that demonstrate that the suspect is “probably” within the premises. We conclude that the explicit commands of the United States and Arizona Constitutions, the language of the Payton standard, and the weight of relevant case authority all compel the conclusion that the reason-to-believe standard requires a level of reasonable belief similar to that required to support probable cause.
¶ 11 Preliminarily, we observe that the standard the trial court applied in evaluating the lawfulness of the search departs from the wording of the standard set forth in
Payton.
As noted,
Payton
authorizes officers who possess a valid arrest warrant to enter a residence in which the suspect lives “when there is reason to believe the suspect is within.”
¶ 12 Although the Court did not use the term “probable cause” in describing the condition precedent to entry of a suspect’s residence, and although it clarified that officers
*24
need not acquire a separate magisterial finding that a suspect is likely within the residence, its reason-to-believe standard bears a striking parallel to the Court’s own previous articulation of the probable-cause standard.
Payton,
¶ 13 Federal and state appellate courts that have addressed the reason-to-believe standard set forth in
Payton
have disagreed whether that standard should be explicitly characterized as equivalent to the probable-cause standard.
Compare United States v. Gorman,
¶ 14 But the dispute has been more anchored in semantics than substance. Those courts that have distinguished reasonable belief from probable cause have done so not because those standards require differing levels of certainty necessary to justify a police action. Rather, they have done so because “probable cause” has become a term of art and has traditionally engendered a need for an additional magisterial finding to authorize police action.
E.g., Route, 104
F.3d at 62;
Magluta,
¶ 15 Thus, the ease authority does not uniformly equate the reason-to-believe standard with the probable-cause standard. But the weight of that authority supports the crux of Smith’s contention — that officers must have an objectively reasonable belief that a suspect is probably home before they may enter it to execute an arrest warrant. The state has cited no case that authorizes entry into a home to execute an arrest warrant based on the mere suspicion or mere possibility that a suspect “might” be present.
¶ 16 As Smith points out, the distinction is far from academic. The state’s interpretation of the reason-to-believe standard, with its use of conditional language, parallels the reasonable-suspicion standard of
Terry v. Ohio,
*25 where a police officer observes unusual conduct which leads him reasonably to conclude in light of his experience that criminal activity may be afoot and that the persons with whom he is dealing may be armed and presently dangerous, where in the course of investigating this behavior he identifies himself as a policeman and makes reasonable inquiries, and where nothing in the initial stages of the encounter serves to dispel his reasonable fear for his own or others’ safety, he is entitled for the protection of himself and others in the area to conduct a carefully limited search of the outer clothing of such persons in an attempt to discover weapons which might be used to assault him.
Id.
at 30-31,
¶ 17 By contrast, the reason-to-believe standard set forth in
Payton
guards against unwarranted intrusions into a suspect’s home. As the Court observed in that case, “the ‘physical entry of the home is the chief evil against which the wording of the Fourth Amendment is directed.’ ”
Payton,
The Fourth Amendment protects the individual’s privacy in a variety of settings. In none is the zone of privacy more clearly defined than when bounded by the unambiguous physical dimensions of an individual’s home — a zone that finds its roots in clear and specific constitutional terms: “The right of the people to be secure in their ... houses ... shall not be violated.” That language unequivocally establishes the proposition that “[a]t the very core [of the Fourth Amendment] stands the right of a man to retreat into his own home and there be free from unreasonable governmental intrusion.”
Id.
at 589-90,
¶ 18 Thus, when we apply the protections of the Fourth Amendment as interpreted by the United States Supreme Court and the protections of our state constitution, we cannot equate the officers’ intrusion into the sanctity of Smith’s residence to the limited investigative intrusions authorized by Terry and its progeny. Therefore, we reject the state’s suggestion that we interpret the reason-to-believe standard set forth in Payton as authorizing entry into Smith’s home based merely on the officers’ reasonable suspicion that he “might” be found within.
¶ 19 For all the above reasons, we conclude that the trial court erred when it found the officers’ entry into Smith’s trailer lawful merely because the officers believed he might have returned there. A mere possibility is not enough.
Cf. State v. Piller,
¶20 Given our conclusion that the trial court applied an inappropriate standard in determining the lawfulness of the officers’ entry into Smith’s home, we need not address whether the court’s terse ruling inappropriately anchored its factual conclusions on the subjective beliefs of the officers. The trial court found that the officers had “believed” Smith might be in the trailer. In so doing, the court neglected to state whether it had found those beliefs to be objectively reasonable based on the totality of the circumstances. On remand, it should do so.
See Valdez,
¶21 Because Smith challenged the credibility of the officers’ testimony based on their behavior once they entered the trailer, because it is not our function to evaluate the demeanor of witnesses, and because the record before us does not contain pertinent facts bearing on whether the officers had a reasonable belief that Smith was within the trailer, we remand the case to the trial court for a hearing to evaluate the evidence under the appropriate standards.
See State v. Barber,
Notes
. The officers disagreed whether those people were released before or after Sergeant Murphy joined Heath’s chase of Smith. According to Deputy Heath, they were still in handcuffs when he returned to the trailer after pursuing Smith. Sergeant Murphy testified, however, that he had released them before he had joined Heath in the unsuccessful pursuit of Smith.
. In
Steagald,
. Smith was on probation at the time the officers entered his home. Moreover, the arrest warrant the officers sought to execute hy entering Smith’s home apparently arose from his alleged violations of probation and was issued at the request of his probation officer. We note that probationary status may reduce a defendant's expectation of privacy and freedom from police searches.
See United States v. Knights,
. See former A.R.S. § 13-1411, now A.R.S. § 13-3891. 1977 Ariz. Sess. Laws, ch. 142, § 134. The statute, of course, must comply and be interpreted consistently with federal and state constitutional principles.
. During oral argument, the state retreated from this position and conceded that the trial court’s use of the conditional tense does not track the language of the Payton standard. The state argued, however, that the evidence presented at the suppression hearing would have justified the officers’ entry even if the court had used the standard required by Payton.
