Justice BENDER
delivered the Opinion of the Court.
I. Introduction
In this interlocutory appeal, we uphold the trial court’s historical findings of facts, substantiated by the record, which support its conclusions of law that the police in this case lacked probable cause to believe that a burglary was in progress and that the police lacked a reasonable basis to believe that there was a colorable claim of an emergency threatening the life or safety of another in the defendant’s home. Accordingly, we hold that the police’s warrantless entry into the defendant’s home was justified by neither the exigent circumstances exception nor the emergency aid exception and violated his constitutional right to be free from unreasonable searches. Thus, we affirm the trial court’s suppression order and remand the case for further proceedings consistent with this opinion.
II. Facts and Proceedings Below
Based on the testimony of Officers Good and Zortman, the only witnesses testifying at two suppression hearings, the pertinent facts are as follows.
Colorado Springs Officers Good and Zort-man responded to an early morning 911 call about a burglary in progress. The caller reported a “lot of racket” and could see possibly four suspects.
The officers went to the specified address and searched the area. After an extensive walk through, the officers found no evidence of a burglary. The officers were about to leave when they encountered two people in a car. The passengers in the car directed the officers to a group of nearby apartments, not the original burglary call address, where [1008]*1008they had heard someone shout “Let her go” and the sound of breaking glass. The first passenger saw two individuals running from the area while the other passenger saw four individuals running.
After speaking with the two people in the car and approximately twenty minutes after the initial dispatch call, Officer Good walked toward the apartments. Upon approaching the apartments, he saw a man walking towards him from the back of the apartment building. Although the man, whom the officers later identified as William Wonza, had blood on his head and face, Officer Good did not believe that Wonza had a serious injury or required immediate attention. Wonza was fully aware and cooperative with the officers. There was a brief exchange between Officer Good and Wonza, during which time Officer Zortman joined them.
At the two suppression hearings, the testimony of Officers Good and Zortman differed as to what Wonza said during the brief exchange. During the first hearing, Officer Good testified on direct that he asked Wonza where he had come from and Wonza indicated an apartment and said only that his friend “Ben was inside.” Consistent with this statement, Officer Good said that after speaking with all of the witnesses, including Wonza, he still did not have any idea about what was going on:
[Wle weren’t exactly sure what we had at that point. According to the witnesses, we weren’t even sure if they made entry into the apartment, whether we actually had a burglary. I mean, we didn’t know what we had, so everyone is a suspect until we find out otherwise, till we clear them all, and then we start figuring out exactly what’s going on.
But upon cross-examination, Officer Good modified his testimony and stated that Won-za told him that “Ben was injured inside” and thus Officer Good became concerned about Ben’s welfare after talking with Won-za. During the second hearing, Officer Good repeated that after speaking with Wonza, he still had “no clue what was going on, so we kind of wanted to gather everyone first, then start asking questions.”
In her testimony, Officer Zortman stated that she did not hear Wonza say a person was injured inside the apartment. Consequently, her official report of events fails to state that Wonza indicated that someone was injured inside the apartment.
During the exchange with Wonza, neither Officer Good nor Zortman asked him who resided in the apartment, whether they had permission to enter the apartment, about the extent of anyone’s injuries, if anyone required medical assistance, who or what had caused any of the injuries, whether the injuries had occurred in the apartment, or whether there was any illegal activity occurring in the apartment.
Despite lacking any understanding of what had happened, Officers Good and Zortman left Wonza with another officer without any further questions or assistance, and walked towards the apartment to investigate with two other officers who had arrived at the scene.
Upon arriving at the backyard deck of the apartment building, the officers noticed broken window glass. They saw no other signs of a disturbance or a burglary. The officers did not hear any noises coming from the building nor did they have any other indication of violence. Upon reaching the apartment door, however, the four officers drew their guns and without knocking or otherwise asking permission to enter, moved into the defendant’s home and down a stairwell toward the defendant’s living space.
The defendant, Benjamin Pate, was standing at the bottom of the stairs. He was injured and bleeding, but calm and cooperative. Officer Good pointed his gun at Pate and asked him to show him his hands and whether there were any other people in the apartment. Pate complied and said there were no other people in the apartment.
The three officers detained Pate while Officer Good conducted a quick search. Finding no one else, Officer Good returned to Pate and asked him if he was carrying any drugs or weapons. Pate said yes, stating that he had ketamine and marijuana in his possession. Officer Good patted him down and discovered thirty-six bags of ketamine, a [1009]*1009Schedule III controlled substance, and less than an ounce of marijuana in Pate’s pockets. While in the apartment, Officer Good did not ask about Pate’s injuries, whether he required medical assistance, whether he had been the victim of a crime or whether any crime had occurred in the apartment.
The officers removed Pate from the apartment and took him outside to question him further. For the first time, the officers asked both Pate and Wonza what had happened. They told the officers that they were victims of assault and robbery. Both Pate and Wonza required medical attention and were taken to the hospital.
Upon the conclusion of the officers’ testimony during the first suppression hearing, the trial court ruled that there was no justification whatsoever for the police officers’ war-rantless entry into Pate’s residence. The trial court found that there was no evidence that the police knocked, that they did not get a response, or that they needed to make a warrantless entry to determine Pate’s well-being. The trial court found that the only evidence available to the police that was reliable was the statement from Wonza that his friend was still in the apartment. The trial court concluded that not only did the police lack probable cause to enter Pate’s apartment, there was not even a reasonable and articulable suspicion that criminal activity had occurred in Pate’s apartment that would justify their intrusion. Thus, the trial court suppressed all evidence and statements secured by the police during their illegal search of Pate’s residence.
On its own motion, the court held a second suppression hearing with additional testimony from the two officers but similarly concluded that the police entered Pate’s apartment in violation of his constitutional rights.
First, the trial court found that the officers did not have probable cause to support any of the traditional exigent circumstances exceptions that would justify a warrantless entry. The police were not involved in hot pursuit and they did not have probable cause to believe that a crime had occurred in the apartment or that evidence would be lost if they did not take immediate action. The trial court found that all of the officers testified repeatedly that they had no idea what was going on and were simply trying to conduct an investigation to make a determination. The trial court concluded that any of the warrantless exceptions based upon probable cause clearly failed for the absence of any probable cause whatsoever.
Second, the trial court ruled that there was no evidence that the officers had a reasonable basis to believe that there was an immediate crisis or emergency in the apartment with respect to Pate’s well-being that required police assistance to justify their illegal intrusion. The trial court found that the officers had an opportunity to question Won-za, who had just come from Pate’s apartment, about whose apartment it was, who was in the apartment, and the extent of the injuries allegedly suffered by Pate. The officers failed to ask any such questions.
The court further found that the first time Officer Good testified, he made no mention of his primary reason in going into the apartment to check on the well-being of Pate. Except when prompted by counsel, at no time did Officer Good state that the officers’ primary purpose was to ascertain the well-being of Pate.
The trial court found that the officers might have been able to determine Pate’s well-being if they had knocked on his door first and questioned Pate before entering his home. Indeed, the trial court determined that the officers’ conduct — entering the apartment guns drawn and without knocking first — was exceedingly dangerous for the officers and Pate.
The trial court further found that the officers’ conduct once they were inside the apartment likewise showed a lack of primary concern for Pate’s well-being. There was no testimony that the police officers asked Pate if he was injured, whether they needed to provide medical assistance to him, whether he was, in fact, a victim of a crime, or whether he had been assaulted during the commission of a crime. Instead, Pate was treated as a suspect throughout the entire encounter. The court concluded that there was no evidence presented that would indicate that the police entered the apartment to provide as[1010]*1010sistance to Pate. Thus, the trial court affirmed its earlier order and suppressed all evidence obtained during the illegal search.
Pursuant to C.A.R. 4.1 and section 16-12-102(2), 6 C.R.S. (2002), the People filed this interlocutory appeal of the trial court’s suppression order.
III. Exceptions to Otherwise Unreasonable and Unconstitutional Warrant-less Searches: Exigent Circumstances and Emergency Aid
When ruling on a motion to suppress, a trial court must engage both in fact-finding — a specific inquiry into the historical phenomena of the case — and law application, which involves the application of the controlling legal standard to the facts established by the evidence. People v. King, 16 P.3d 807, 812 (Colo.2001)(internal citations omitted). The trial court’s findings of historical facts are entitled to deference and will not be overturned if supported by competent evidence in the record. See People v. Rivas, 13 P.3d 315, 320 (Colo.2000).
The role of the appellate court, however, is to determine whether the trial court’s legal conclusions are supported by sufficient evidence and whether the trial court applied the correct legal standards. When no controlling facts are in dispute, the appellate court may review the issue de novo because the legal effect of undisputed controlling facts is a question of law. Id. Because we find that no controlling facts are in dispute here, we turn to a discussion of the legal standards.
Both the United States and Colorado Constitutions bar unreasonable searches and seizures. See U.S. Const. amend. IV; Colo. Const. art. II, § 7. We have held that a warrantless search and seizure is presumptively unreasonable unless justified by one of the well-established exceptions to the Warrant Clause of the Fourth Amendment. See People v. Hebert, 46 P.3d 473, 478 (Colo.2002). The burden is on the prosecution to prove one of these exceptions. See People v. Amato, 193 Colo. 57, 60, 562 P.2d 422, 423 (1977). To determine whether the prosecution has met its burden, courts must examine the totality of the circumstances as they would have appeared to “a prudent and trained police officer” at the time the decision to conduct a warrantless entry was made. Hebert, 46 P.3d at 480; People v. Grazier, 992 P.2d 1149, 1154 (Colo.2000).
One such exception to the Warrant Clause applies when exigent circumstances exist that necessitate immediate police action. People v. Kluhsman, 980 P.2d 529, 534 (Colo.1999). Under the exigent circumstances exception, the prosecution must prove (1) the presence of probable cause and (2) an exigent circumstance that justifies a warrantless entry. Id. We have held that three situations qualify as “exigent circumstances” that would justify such an unauthorized entry: (1) when police are engaged in “hot pursuit” of a fleeing suspect; (2) there is a risk of immediate destruction of evidence; or (3) there is a colorable claim of an emergency situation threatening the life or safety of another. Id.
The emergency situation has been invoked in burglary cases when police officers make a warrantless entry into a residence to secure the premises and search for suspects and victims. See, e.g., People v. Unruh, 713 P.2d 370, 379 (Colo.1986). However, to justify a warrantless entry, police must have probable cause to believe that a burglary recently occurred or may be in progress. Grazier, 992 P.2d at 1154.
In Grazier, for example, we upheld the trial court’s suppression order in a burglary case because the police lacked probable cause to enter a residence without a warrant under the exigent circumstances exception. Id. at 1156. In that case, the police received a 911 call about a possible burglary in progress. The caller reported observing men enter an apartment through a window, open the door to let another man into the apartment, and then close the curtains. The caller, a neighbor to the apartment, did not think that any of the men lived at the apartment. Id. at 1151.
When the police investigated the apartment, however, they did not observe any signs of a burglary in progress. There was no forced entry. They did not hear any noises or see any other suspicious movement. Through the window they saw a man inside [1011]*1011but he was not armed and posed no apparent threat. The officers knocked on the door and the man answered. Without questioning him about whether he lived there or his identify or the reason for his presence, the officers handcuffed him and entered the apartment. Id. at 1152,1155.
On such facts, we held that the trial court correctly ruled that the police officers’ observations did not establish probable cause to believe that there was a burglary in progress. Id. at 1155-56. Suspicion alone does not rise to the level of probable cause. Id. at 1154. The police officers failed to act reasonably under the circumstances and thus could not invoke the exigent circumstances exception to justify their unconstitutional entry.
A second established exception to the Warrant Clause is the emergency aid exception. The emergency aid exception also requires a “colorable claim of an emergency threatening the life or safety of another.” Hebert, 46 P.3d at 479. However, unlike the exigent circumstances exception, the emergency aid exception requires the prosecution to prove the existence of “an immediate crisis and the probability that [police] assistance will be helpful.” Amato, 193 Colo. at 60, 562 P.2d at 424. Also, the emergency aid doctrine does not require probable cause. Id.; see also Kluhsman, 980 P.2d at 535 n. 7.
The factual contexts in which we have applied the emergency aid exception explain the absence of the usual probable cause requirement for warrantless searches. For example, when police respond to a fire or other similar emergency, it is easy to understand why they are not required to have probable cause. See Hebert, 46 P.3d at 478.
The more difficult situation arises when police officers are originally investigating a scene but then make a warrantless entry to aid an individual in need of emergency assistance. Id. If the officer’s purpose in entering a place without a warrant is to render emergency assistance, then police need not have probable cause to believe that contraband or other evidence of criminal activity is located at a particular place. Id.
Although no usual probable cause is required under the emergency aid exception, police must have a reasonable basis approximating probable cause to associate the emergency with the area or place to be searched. Id. at 479. As we have explained in the past, the “reasonable basis” allows police to make warrantless entries only when there are facts to support the conclusion that someone’s life or safety is seriously threatened:
[T]he emergency aid exception does not give police officers carte blanche to make a warrantless entry whenever there is a theoretical possibility that another’s life or safety is in danger; rather, there must be a colorable claim that another’s life or safety is in danger.
Id. We applied the reasonable basis test in People v. Thompson, 770 P.2d 1282 (Colo.1989), where we upheld the police officers’ warrantless entry because there was a color-able claim that someone’s life or safety was in danger.
In Thompson, the police responded to a 911 domestic violence call. 770 P.2d at 1284-85. When they arrived at the scene, the officers observed several spent bullet casings on the driveway, blood on the front porch, the front door, and on the side of the house next to the front door, a front door ajar several inches, and shattered glass. Observing these signs of violence, the police knocked on the door. A woman answered who had blood covering her face and clothes and was holding an ice pack to her head. Id. We concluded that the police’s subsequent entry into the residence, without a warrant and without the woman’s permission, was necessary and authorized under the emergency aid exception given the signs that suggested the woman’s safety was in danger. Id. at 1286.
Having discussed two exceptions that would justify a warrantless entry into a person’s home, we turn to an application of these exceptions to the facts of this case as found by the trial court.
IY. The Police Officers’ Warrantless Entry into Pate’s Home Was Not Justified By Either the Exigent Circumstances Exception or the Emergency Aid Exception to the Warrant Clauses to the U.S. and Colorado Constitutions
The People argue that both the exigent circumstances and the emergency aid excep[1012]*1012tions exist here to justify the police officers’ warrantless entry into Pate’s home.
First, the People argue that they have shown that there was probable cause for the officers to believe that a burglary had just taken place or was currently taking place in Pate’s apartment so as to invoke the exigent circumstances exception. In support of their argument, the People state that the officers received a 911 call about a burglary in progress and witnesses on the scene reported hearing suspicious noises (a loud commotion and a woman screaming) and seeing men run from the area. In addition, the police talked with an injured man who said his friend remained inside an apartment, possibly injured, and saw broken glass at the entrance to the same apartment.
Second, the People argue that even if the officers did not have probable cause to invoke the exigent circumstances exception, the police officers’ testimony proves that the warrantless entry into Pate’s residence was justified under the emergency aid exception because the police had a reasonable basis to believe that an immediate crisis existed and there was a probability that their assistance would be useful. The witnesses told the police that they heard shouting, a woman screaming, the sound of breaking glass, and saw two or four men running from the scene. The officers encountered an injured man who said that his friend was inside, also possibly injured, and observed a broken apartment window. The People conclude that the officers’ testimony clearly shows that the officers entered the apartment to render emergency aid.
We disagree. We must defer to the factual findings of the trial court and thus conclude that based on those facts, neither exception applies. Under the totality of the circumstances as they would have appeared to a prudent and trained police officer at the time, we agree with the trial court that the police officers’ warrantless entry into Pate’s home violated his constitutional right to be free from an unreasonable search and seizure.
A. Exigent Circumstances
The People failed to prove that the police officers had probable cause to believe that an exigent circumstance existed that would justify their warrantless search. Unquestionably, as found by the trial court, exigent circumstances such as the “hot pursuit” of a fleeing suspect or the risk of immediate destruction of evidence were not present here. Thus, the People must show that the police officers had probable cause to believe that there was an emergency situation — such as a burglary in progress — that would justify a warrantless search to secure the premises and search for suspects and victims.
The People have failed to prove such an emergency situation. Although the officers might have been suspicious that a burglary had occurred, such suspicion did not rise to the level of probable cause. Grazier, 992 P.2d at 1154. On the contrary, the officers’ own testimony regarding their observations of Pate’s apartment and their encounter with the key witness, Wonza, show not only that they did not have probable cause to believe a burglary occurred, but they did not have probable cause to believe that any illegal activity had occurred in Pate’s apartment.
At the apartment, the officers testified that, with the exception of the broken window glass, there was no other indication of a burglary in progress or any other disturbance. They did not hear any noises. They did not see any other signs of a forced entry. They did not see any other signs of violence or suspicious movement. Id. at 1152, 1155; cf. People v. Berow, 688 P.2d 1123, 1125-26 (Colo.1984)(holding that officers could have reasonably believed that a burglary was in progress based on evidence showing that the apartment owner was out of town, the locks of the apartment door had been forcibly removed, and a witness saw suspicious movement inside the apartment).
Despite the lack of observable evidence that a burglary had occurred at Pate’s apartment, the police failed to question the key witness who might have provided them with probable cause to enter the apartment without a warrant to secure the premises and search for victims and suspects. The police [1013]*1013did not ask Wonza any questions critical to a burglary investigation. They did not ask him who lived in the apartment, whether a burglary had occurred, if Wonza’s or Pate’s injuries were related to a burglary or other criminal activity, whether Wonza or Pate were victims or perpetrators of a burglary, or whether any other victims or perpetrators were still inside. Cf. Kluhsman, 980 P.2d at 535 (holding that exigent circumstances justified officers’ warrantless entry into defendant’s home after defendant told them that he had just killed someone and people remained inside his home).
Indeed, the police testified repeatedly that after speaking with Wonza, they did not know what type of situation they faced. They did not know whether there had been an entry into Pate’s apartment or whether it had been burglarized. The stated purpose of the officers’ warrantless entry was not to secure the home because they believed a burglary might be in progress but rather to “gather everyone first and then figure out what had happened.” Thus, the police entered the apartment guns drawn, without knocking and without inquiring first from the people outside or inside what might have happened.
On such facts, we hold that the trial court correctly ruled that the police officers’ observations in this ease did not establish probable cause to believe that there was a burglary in progress in Pate’s home. Grazier, 992 P.2d at 1155-56. Thus, the police officers failed to act reasonably under the totality of the circumstances and cannot invoke the exigent circumstances exception to justify their unconstitutional entry.
B. Emergency Aid
We also conclude, as did the trial court, that the People failed to prove that an immediate crisis existed and that the probability that police assistance would be helpful, either of which would be sufficient to invoke the emergency aid exception. Although the police are not required to have probable cause under this exception, they must have a “reasonable basis approximating probable cause” to associate the emergency with the area or place to be searched. Hebert, 46 P.3d at 479. No such reasonable basis existed here.
First, there was no evidence of an “immediate crisis” in Pate’s home. The police responded to a call about a burglary in progress at an address that was not Pate’s address. The call did not include any report of violence or any other situation that might suggest an armed or dangerous perpetrator. Cf. Thompson, 770 P.2d at 1284 (domestic violence call); People v. Mascarenas, 972 P.2d 717, 719 (Colo.App.1998)(same). After responding to the area, the police found no observable evidence of a burglary or any other criminal activity at the original address. It was not until twenty minutes after the dispatch call that they encountered the injured Wonza coming from a different apartment. See Hebert, 46 P.3d at 480 (holding that “significant lag time” indicates that there was no immediate crisis justifying warrantless entry).
When the police encountered Wonza, the trial court found that the only reliable information they had was that Wonza was bleeding and that he had come from the nearby apartment where someone named “Ben” remained inside. The officers testified that they did not know anything about what had occurred to Wonza or the person who remained in the apartment. Before entering the apartment, the officers did not ask about the extent of anyone’s injuries, whether anyone required medical attention, or whether the injuries actually occurred in the apartment. The officers also did not seek or receive any information that any illegal activity was ongoing or that any suspects, dangerous or otherwise, remained in the apartment. The officers here had no reliable or credible evidence that connected an immediate crisis or an emergency threatening someone’s life or safety with Pate’s specific apartment. Cf. Thompson, 770 P.2d at 1284, 1286 (holding that the police could invoke the emergency aid exception to enter a house without a warrant when the officers observed several spent bullet casings in the driveway; blood all over the outside of the house; the front door ajar several inches; shattered glass in the front door; and the woman answering the door after the police knocked had blood [1014]*1014on her face and held an ice pack to her head). Although it remained in the “realm of possibilities” that an injured victim was in Pate’s residence, this claim, as found by the trial court, was unsubstantiated by any reliable facts. See Hebert, 46 P.3d at 481. Thus, the officers in this case had no reasonable basis approximating probable cause to believe that an immediate crisis or emergency existed to justify their entry into Pate’s home without a warrant or without seeking his permission to do so.
Even if we were to hold that the officers had a reasonable basis to believe that someone’s life or safety was in danger in Pate’s home, there exists no evidence to show that the officers entered the home to provide emergency assistance consistent with that belief. The officers made no attempt to knock on the door to obtain permission to enter and determine if anyone actually needed emergency assistance.
As the trial court found under the circumstances of this case, the officers’ entry into the apartment — guns drawn, without knocking first, and without any information about Pate’s well-being or what was occurring inside — was exceedingly dangerous to all involved. Indeed, had the officers knocked first and questioned Pate before entering his apartment, they may have obtained his consent to enter or information to provide them with a reasonable basis to believe an emergency situation existed that would allow them to enter his residence to provide assistance without such consent or a warrant. See, e.g., Thompson, 770 P.2d at 1284; Mascarenas, 972 P.2d at 720.
Instead, without any information as to Pate’s well-being or what was occurring inside, the officers went into the apartment and pointed guns at the injured and bleeding Pate who had just been assaulted and robbed. At no time inside the apartment did the officers inquire about Pate’s injuries, whether he required medical assistance, or whether he had been the victim of a crime. After searching the apartment, the first question that the officers asked Pate was not whether he required their assistance, but whether he had drugs or weapons.
Indeed, as supported by the officers’ testimony and found by the trial court, the purpose of the officers’ warrantless entry into Pate’s home was not to provide emergency assistance, but rather to investigate. During his direct examination, Officer Good never stated that the officers entered the apartment with the intent to render medical aid to the injured occupant. Officer Good only mentioned the topic of emergency assistance during cross-examination. Instead, Officer Good testified repeatedly that they were “trying to figure out what was going on,” a task that is more consistent with the officers’ duties as investigators. Because the trial court found as a fact that the officers entered Pate’s home to investigate, and not because they reasonably believed that someone’s life or safety was in danger, they were not authorized to enter without a warrant under the emergency aid exception. Hebert, 46 P.3d at 479.
In sum, the trial court’s findings of historical fact in this case are amply supported by the record and thus must be given deference. Under our de novo review, we conclude that such facts support the trial court’s legal conclusion that neither the exigent circumstances exception nor the emergency aid exception authorized the police officers to enter Pate’s home without a warrant. Thus, we hold that the police officers’ conduct in this case violated Pate’s constitutional right to be free from unreasonable searches and any evidence obtained as a result of such a search must be suppressed.
V. Conclusion
For the reasons stated above, we affirm the trial court’s suppression order and remand this case back to that court for further proceedings consistent with this opinion.
Justice COATS dissents, and Justice KOURLIS and Justice RICE join in the dissent.