The People appeal from the grant of defendant’s motion to suppress a gun, which he has been charged with possessing. Both the arresting officer and defendant testified at the suppression hearing.
Police Officer Stephanie Sheffler, a three-year member of the New York City Police Department, testified that on September 14, 1984, at approximately 4:30 a.m., she and her partner, who were on motor patrol, received a radio report of a possible burglary in progress at a roller disco at 155th Street and Eighth Avenue in Manhattan. The perpetrators were described as two black men, one dressed in dark clothing and the other wearing a red top. They were reported to be "up on the roof there, on a fire escape.” The tape of both the 911 call and the radio transmission was played at the hearing. Insofar as is relevant, the caller told the police operator:
"I would like to report a robbery going on at 155th Street & Macombs at . the Rooftop Roller Skating Disco * * *
"I see some people going up and down the fire escape— there’s two guys, they’re right in the front—it looks like they’re looking out, and the place is closed * * *
"It’s a ground level disco. It doesn’t have but one level. They’re going up the fire escape. It’s one of those fire escapes that teeter.”
Although she had never been inside the building in question, *636a one-story structure, Officer Sheffler knew that it contained a social club. She was also familiar with the high incidence of crime in the area.
The officers were at the scene within a matter of minutes. The building’s gates were down and it appeared to be closed. Defendant, a black man dressed in a denim jacket and dark blue jeans, was standing at the top of the fire escape. Officer Sheffler also observed a second black man, with a red shirt, standing in the doorway. Alighting from the patrol car with her gun drawn, as her partner headed toward the red-shirted man some 40 feet away, Officer Sheffler approached the fire escape, on which defendant stood 12 feet overhead, and ordered him down. When defendant asked if he could use the inside stairway, Officer Sheffler, unfamiliar with the building’s inner structure, repeated her order. Defendant complied. When he reached the ground, Officer Sheffler, without further inquiry, placed him against the wall and patted him down, in the course of which she recovered a bolstered, loaded .38 caliber revolver from his front waistband. Defendant was immediately arrested.
Defendant testified that he was employed at the social club, working primarily as a cleaner between midnight and 8:00 a.m. At the time of his arrest he was carrying a gun which, earlier that evening, one of the club’s workers, a man he knew only as Kurt, had asked him to hold. Several times that night he had gone to the roof for some air and to smoke a cigarette. On his last visit, as he sat near the fire escape, smoking, he heard whistling. Looking up at the adjoining viaduct overhead he saw two police officers, who, with guns drawn, ordered him not to move. On the street a female officer, with her gun also drawn, asked him what he was doing and ordered him down from the fire escape. When his request to come down through the building stairway was rejected, he descended the fire escape.
Once on the ground, defendant, his protests that he worked at the social club notwithstanding, was handcuffed by the female officer who, nervous and frightened, asked him to step against the wall and patted him down. Finding nothing, the officer pulled defendant away from the wall and patted him down again, at which time the gun was discovered and seized.
In granting the motion to suppress the court found neither probable cause for an arrest nor justification for a frisk. Despite its finding that Officer Sheffier’s observations at the *637scene confirmed the anonymous tip, it ruled that, as a matter of constitutional law, a lawful arrest could not be predicated upon the "mere confirmation” of such tip without affording defendant an opportunity to explain himself. Although conceding that Officer Sheffler had a reasonable basis "for temporarily detaining” defendant for questioning, the court found that she had no basis upon which to believe that he was armed. Moreover, since it accepted defendant’s testimony that Officer Sheffler handcuffed him before she placed him against the wall and frisked him, the court found that the officer was not in any danger. Thus, the frisk could not be justified. Since I believe that, given the circumstances confronting her, Officer Sheffler’s conduct in ordering defendant, at gunpoint, to come down from the fire escape and frisking him was eminently proper, I would reverse and deny the motion to suppress.
As the 911 tape makes clear, an anonymous caller, an obvious eyewitness to the events he was describing, reported what he believed to be a burglary in progress. He identified the building and described the perpetrators, who were reported "going up and down the fire escape.” This information was then relayed to Officer Sheffler and her partner who, within minutes, responded to the scene. There, at 4:30 in the morning, in a high crime area, Officer Sheffler saw defendant on the fire escape and another man in the doorway of a commercial building which in all respects appeared closed. These observations alone were enough to compel the conclusion that a crime was being committed. The reasonableness of this conclusion was only heightened by the validation of the anonymous caller’s information. Not only did the two men match the description of the perpetrators but one of them, defendant, was still on the fire escape, as the caller had reported. Thus, Officer Sheffler knew that these were the same two men who, minutes earlier, had been on the roof or fire escape, and whose activities had aroused the suspicions of the anonymous caller. The reliability of the anonymous caller and the basis of his knowledge are established simultaneously by the officer’s own observations (People v Elwell, 50 NY2d 231, 237; see, People v Rodriguez, 52 NY2d 483, 489-490, 493-494). These observations and the content of the radio transmission provided probable cause. "Probable cause requires, not proof beyond a reasonable doubt or evidence sufficient to warrant a conviction * * * but merely information which would lead a reasonable person who possesses the same expertise as the officer to conclude, under the circumstances, that a crime is *638being or was committed”. (People v McRay, 51 NY2d 594, 602.) Having probable cause to believe that defendant was engaged in the commission of a crime, Officer Sheffler could lawfully arrest him and search him as an incident thereto. (People v Stokes, 57 AD2d 797.) Thus, the gun was lawfully recovered as an incident to an arrest.
The suppression court believed, however," that the mere confirmation of the anonymous caller’s information was insufficient and that, as a matter of constitutional law, Officer Sheffler was obliged to afford defendant the opportunity to explain his actions before any formal arrest could take place. The requirements of probable cause, however, do not impose any such duty. Confronted with a situation fraught with danger, and in receipt of information which leads him to believe that he is witnessing a crime, a police officer should not be powerless to act until he has engaged a suspected criminal in conversation. In any event, probable cause is not vitiated by a suspect’s mere assertion of an innocent explanation for his conduct. Nor did the circumstances confronting Officer Sheffler impose a duty to inquire.
Moreover, even if Officer Sheffler did not have probable cause to arrest defendant based on her observations, her actions were nevertheless reasonable under the circumstances. She knew that two men had been observed on the roof or the fire escape of a closed building. Upon arriving at the scene, she was able to confirm the information provided in the radio transmission. The building was located in a high crime area. These factors, taken together, certainly formed the basis, at the very least, of a reasonable suspicion that defendant was committing or had committed a burglary. At that point Officer Sheffler had the right to stop defendant and inquire about his activities as well as the concomitant right to frisk him to neutralize any danger to herself. When an officer "confronts an individual whom he reasonably suspects has committed, is committing or is about to commit such a serious and violent crime as * * * burglary * * * that suspicion not only justifies the detention but also the frisk, thus making it unnecessary to particularize an independent source for the belief of danger.” (People v Mack, 26 NY2d 311, 317.)
The suppression court, however, found that defendant was handcuffed before he was frisked and that therefore he posed no danger to her. Thus, the court held, Officer Sheffler’s conduct could only be justified by a finding of probable cause. Such a factual finding was unjustified and unreasonable and *639does not bind this court. Officer Sheffler’s testimony that defendant was frisked before he was arrested was straightforward and clear:
"Q. Did the defendant eventually come down off the fire escape?
"A. Yes, he did.
"Q. When he got to the ground, what did you do?
"A. I placed him against the wall and frisked him.
"Q. When you say frisked, what exactly did you do?
"A. Pat down his outer clothing.
"Q. And in the course of that pat down, what did you do?
"A. I felt a bulge in front of the—I reached in. He had a gun concealed in the waistband in a holster.
"Q. What type of gun was it?
"A. Loaded .38—
"Q. What did you do after that?
"A. I placed the defendant under arrest * * *
"Q. But he was coming down carefully and you had him under your observation from the time he first saw him until the time he hit the ground?
"A. Yes.
"Q. And you saw nothing on him then?
"A. Not that I can remember.
"Q. And then you asked him to place his hand up or you ordered him to place his hands on the wall and you proceeded to search him?
"A. Yes.”
Given defendant’s obvious motive to lie about the incident, there was no reasonable basis for disregarding such testimony and crediting instead defendant’s uncorroborated and self-serving testimony to the contrary.
Accordingly, the order appealed from should be reversed, the motion to suppress denied and the matter remanded for further proceedings.
Ellerin, J., concurs with Fein, J; Kassal, J., concurs in a separate opinion; Kupferman, J. P., and Sullivan, J., dissent in an opinion by Sullivan, J.
Order, Supreme Court, New York County, entered on February 14, 1985, affirmed.