delivered the opinion of the Court.
In
Richards
v.
Wisconsin,
Alan Shelby was a prisoner serving concurrent state and federal sentences in the Oregon state prison system. On November 1,1994, the Tillamook County Sheriff’s Office took temporary custody of Shelby, expecting to transport him to the Tillamook County Courthouse, where he was scheduled to testify. On the way to the courthouse, Shelby slipped his handcuffs, knocked over a deputy sheriff, and escaped from custody.
It was not the first time Shelby had attempted escape. In 1991 he struck an officer, kicked out a jail door, assaulted a woman, stole her vehicle, and used it to ram a police vehicle. Another time he attempted escape by using a rope made from torn bedsheets. He was reported to have made threats to kill witnesses and police officers, to have tortured people with a hammer, and to have said that he would “ ‘not do federal time.’” App. to Pet. for Cert. 38a. It was also thought that Shelby had had access to large supplies of weapons.
Shortly after learning of Shelby’s escape, the authorities sent out a press release, seeking information that would lead to his recapture. On November 3, a reliable confidential informant told Bureau of Alcohol, Tobacco, and Firearms Agent George Kim that on the previous day he had seen a person he believed to be Shelby at respondent Hernán Ramirez’s home in Boring, Oregon. Kim and the informant then drove to an area near respondent’s home, from where Kim observed a man working outside who resembled Shelby.
Based on this information, a Deputy United States Marshal sought and received a “no-knock” warrant granting permission to enter and search Ramirez’s home. Around this time, the confidential informant also told authorities that respondent might have a stash of guns and drugs hidden in *69 his garage. In the early morning of November 5, approximately 45 officers gathered to execute the warrant. The officers set up a portable loudspeaker system and began announcing that they had a search warrant. Simultaneously, they broke a single window in the garage and pointed a gun through the opening, hoping thereby to dissuade any of the occupants from rushing to the weapons the officers believed might be in the garage.
Respondent and his family were asleep inside the house at the time this activity began. Awakened by the noise, respondent believed that they were being burglarized. He ran to his utility closet, grabbed a pistol, and fired it into the ceiling of his garage. The officers fired back and shouted “police.” At that point respondent realized that it was law enforcement officers who were trying to enter his home. He ran to the living room, threw his pistol away, and threw himself onto the floor. Shortly thereafter, he, his wife, and their child left the house and were taken into police custody. Respondent waived his Miranda rights, and then admitted that he had fired the weapon, that he owned both that gun and another gun that was inside the house, and that he was a convicted felon. Officers soon obtained another search warrant, which they used to return to the house and retrieve the two guns. Shelby was not found.
Respondent was subsequently indicted for being a felon in possession of firearms. 18 U. S. C. § 922(g)(1). The District Court granted his motion to suppress evidence regarding his possession of the weapons, ruling that the police officers had violated both the Fourth Amendment and 18 U. S. C. § 8109 because there were “insufficient exigent circumstances” to justify the police officers’ destruction of property in their execution of the warrant. App. to Pet. for Cert. 34a.
The Court of Appeals for the Ninth Circuit affirmed.
In two recent eases we have considered whether and to what extent “no-knock” entries implicate the protections of the Fourth Amendment. In
Wilson
v.
Arkansas,
In
Richards
v.
Wisconsin,
Neither of these cases explicitly addressed the question whether the lawfulness of a no-knock entry depends on whether property is damaged in the course of the entry. It *71 is obvious from their holdings, however, that it does not. Under Richards, a no-knoek entry is justified if police have a “reasonable suspicion” that knocking and announcing would be dangerous, futile, or destructive to the purposes of the investigation. Whether such a “reasonable suspicion” exists depends in no way on whether police must destroy property in order to enter.
This is not to say that the Fourth Amendment speaks not at all to the manner of executing a search warrant. The general touchstone of reasonableness which governs Fourth Amendment analysis, see
Pennsylvania
v.
Mimms,
Applying these principles to the facts at hand, we conclude that no Fourth Amendment violation occurred. A reliable confidential informant had notified the police that Alan Shelby might be inside respondent’s home, and an officer had confirmed this possibility. Shelby was a prison escapee with a violent past who reportedly had access to a large supply of weapons. He had vowed that he would “‘not do federal time.’” The police certainly had a “reasonable suspicion” that knocking and announcing their presence might be dangerous to themselves or to others. 2
As for the manner in which the entry was accomplished, the police here broke a single window in respondent’s garage. They did so because they wished to discourage Shelby, or any other occupant of the house, from rushing to the weapons that the informant had told them respondent might have *72 kept there. Their conduct was clearly reasonable and we conclude that there was no Fourth Amendment violation. 3
Respondent also argues, however, that suppression is appropriate because the officers executing the warrant violated 18 U. S. C. §3109. This statutory argument fares no better. Section 3109 provides:
"The officer may break open any outer or inner door or window of a house, or any part of a house, or anything therein, to execute a search warrant, if, after notice of his authority and purpose, he is refused admittance or when necessary to liberate himself or a person aiding him in the execution of the warrant.”
Respondent contends that the statute specifies the only circumstances under which an officer may damage property in executing a search warrant, and that it therefore forbids all other property-damaging entries.
But by its terms § 3109 prohibits nothing. It merely authorizes officers to damage property in certain instances. Even accepting,
arguendo,
that the statute implicitly forbids some of what it does not expressly permit, it is of no help to respondent. In
Miller
v.
United States,
In this case the question is squarely presented. We remove whatever doubt may remain on the subject and hold that §3109 codifies the exceptions to the common-law announcement requirement. If § 3109 codifies the common law in this area, and the common law in turn informs the Fourth Amendment, our decisions in
Wilson
and
Richards
serve as guideposts in construing the statute. In
Wilson
v.
Arkansas,
*74 We accordingly reverse the judgment of the Court of Appeals and remand this case for further proceedings consistent with this opinion.
It is so ordered.
Notes
It should be noted that our opinion in Richards came down after the Court of Appeals issued its opinion in this case.
It is of no consequence that Shelby was not found. “[I]n determining the lawfulness of entry and the existence of probable cause we may concern ourselves only with what the officers had reason to believe
at the time of their entry.” Ker
v.
California,
After concluding that the Fourth Amendment had been violated in this case, the Ninth Circuit farther concluded that the guns should be excluded from evidence. Because we conclude that there was no Fourth Amendment violation, we need not decide whether, for example, there was sufficient causal relationship between the breaking of the window and the discovery of the guns to warrant suppression of the evidence. Cf.
Nix
v.
Williams,
