Robert Combs appeals his conviction, following a bench trial, for maintaining a place for the manufacture of controlled substances, attempting to manufacture methamphetamine, being a felon in possession of a firearm, and criminal forfeiture. Combs asserts the district court erred in denying his motion to suppress evidence resulting from a search of his residence because the police did not physically knock on his door and therefore failed to adequately “knock and announce” before executing the search warrant. Whether the Fourth Amendment requires an actual “knock” on the door of a suspect’s home before a search can be conducted is an issue of first impression in our circuit. We hold that under the totality of the circumstances presented in this case, the police acted reasonably in executing the warrant without first physically “knocking” on the front door of Combs’s residence. Because there was no Fourth Amendment violation, we affirm the district court.
I.
Background
After receiving an anonymous tip, Anchorage Police began investigating possible methamphetamine production and drug trafficking at the home of Robert Combs. A search warrant issued, based upon information obtained from the investigation, to search Combs’s home at any time of the day or night for evidence of misconduct involving controlled substances.
On the morning of September 12, 2002, the search warrant was executed with the assistance of a Crisis Intervention Response Team (“CIRT”), a tactical police unit, trained and equipped to handle high risk raids on suspected methamphetamine labs, which may involve exposure to various flammable, explosive, and toxic chemicals. The CIRT officers wore protective gear consisting, of flash fire resistant Nome?: balaclavas, gas maskg, one-piece No-mex flight suits and Kevlar vests with police insignia.
Anchorage Police Lieutenant Steven Smith was in command. He had spent nearly seventeen years with the Anchorage Police Department, ten' of which were with the CIRT. During those ten years, Lieutenant Smith participated in somewhere between thirty to forty warrant services. In addition to Lieutenant Smith, approximately ten to twelve CIRT officers were involved in the entry of Combs’s house. Six officers were to make the actual entry at the door at the back of the house, while four to six additional officers were to provide cover.
When Lieutenant Smith arrived at the scene, he noticed smoke coming from the chimney and an acrid smell in the air. He also noticed what appeared to be an open flame at a window in the northeast corner of the house. Because the smoke and flame indicated that the occupants might be involved in the dangerous process of cooking methamphetamine, he became concerned for- the CIRT unit’s safety. There were- flood lights and two surveillance cameras attached to the house and the windows to the garage were papered over. The officers knew the house was occupied because a woman was seen enter *742 ing the house just before the warrant was executed.
Service of the warrant commenced when Lieutenant Smith parked his marked police car, with the overhead lights flashing, in front of the house and began making announcements regarding the warrant service over the public address system in the front grill of the vehicle. Lieutenant Smith repeatedly publicly announced, for a period of thirty seconds to a minute, “Anchorage Police with a warrant for 1502 West 32nd Avenue.”
Although Lieutenant Smith could not see the approach of the CIRT from the south of the building, he heard the entry team officers around the location announcing, “Anchorage Police with a warrant.” Sergeant Soto, a member of the CIRT, was part of the group approaching the back door to make entry. Soto’s role during the search was to be the “breaeher.” He carried a metal battering ram and halogen tools for this purpose. When the team members finished assembling at the door, they waited while Lieutenant Smith continued to announce the police presence with a search warrant. At some point, Soto’s team leader told him to breach. Soto hit the door on the doorknob side with the battering ram four or five times without success. His team leader instructed him to hit the hinged side of the door. After two hits, the door broke open and the officers entered the house. Soto estimated that he spent a total of ten to twelve seconds pounding on the door with the battering ram.
The subsequent search of the house resulted in the seizure of, among other things, evidence of an active methamphetamine lab, firearms, and currency from drug trafficking. Officers also obtained a statement from Combs after he was placed under arrest and advised of his rights. Combs moved for suppression of all of this evidence, arguing in part that the manner of execution of the search warrant was unreasonable because the police failed to properly “knock and announce” before breaching the door. 1
II.
Discussion
The common-law principle that law enforcement officers should “knock and announce” their presence and authority before entering a dwelling is part of the reasonableness inquiry under the United States Constitution’s Fourth Amendment guarantee against unreasonable searches and seizures.
Wilson v. Arkansas,
A. The “Knock and Announce” Rule
That the government must announce its presence before entering a private home is a longstanding principle. In
Wilson,
the Supreme Court traced its origins to English common law.
While the definition of “reasonableness” was left for another day, the
Wilson
opinion does provide guidance in determining what is reasonable. The Court set forth a non-exhaustive list of occasions when “the presumption in favor of announcement necessarily ... give[s] way to contrary considerations.”
Id.
at 935,
Since
Wilson,
the Court has reiterated that the knock and announce principle is a part of the reasonableness inquiry rather than a prerequisite for constitutional entry.
See U.S. v. Banks,
B. The “Knock”
With this guidance from the Supreme Court, we cannot accept Combs’s assertion that without a literal knock, the entry into his home was per se unreasonable under the Fourth Amendment. Nor can we accept the government’s position that a knock is never necessary under the Fourth Amendment. Neither of these strict categorical approaches is consistent with the reasonableness inquiry laid out by the Supreme Court.
See Banks,
The general practice of physically knocking on the door, announcing law enforcement’s presence and purpose, and receiving an actual refusal or waiting a sufficient amount of time to infer refusal is the preferred method of entry. See
Banks,
Although “knock and announce” is the preferred method of entry, given the totality of the circumstances in a particular case, it is not invariably required by the Fourth Amendment. In some circumstances, it may be necessary to dispense with the knock and announcement entirely.
See, e.g., U.S. v. Peterson,
To determine whether an entry is reasonable, we must consider all the circumstances surrounding the entry, including, but not limited to, officer safety,
Wilson,
In
U.S. v. Spikes,
the Sixth Circuit adopted this view in a case involving the “knock” component of knock and announce. In
Spikes,
the police announced their presence while running up the stairs to the front porch.
Spikes,
C. Application of the Reasonableness Test
We conclude that the entry was reasonable in this case, even though a literal knock was not made. First, there was reason for the officers to be concerned for their safety. The house was equipped with security cameras and flood lights. Windows were papered over, suggesting that the occupants of the home were concerned with protecting their illegal methamphetamine laboratory.
See U.S. v. Cline,
Second, the officers announced their presence to the extent possible given their legitimate safety concerns. They parked in front of the house in a marked police car with the overhead lights flashing. Lieutenant Smith repeatedly announced over a loudspeaker, “Anchorage Police with a warrant for 1502 West 32nd Avenue.” Given the small size of the house, the time of day, the officer’s knowledge that there was at least one occupant awake in the house, and that officers on the other side of the house heard the announcement, the district court’s finding that “the residents of Combs’ small home heard the police *746 announce their presence and demand entry and disregarded that request” was not clearly erroneous. Moreover the occupants of the home could have had no doubt that the police had arrived to search their residence as the announcements repeatedly gave the street address of their home.
Given these circumstances, we find that law enforcement’s actions were reasonable and the warrant’s execution complied with the requirements of the Fourth Amendment. We do not suggest that the absence of any of these factors would compel a contrary conclusion. The factors we have listed are simply part of our “case by case” examination. Just as it is not permissible to “turn[ ] the notion of a reasonable time under all the circumstances into a set of sub-rules,” likewise it is not appropriate to turn the knock and announce requirement “into a set of sub-rules.”
Banks,
III.
Conclusion
Because the state police acted reasonably under the Fourth Amendment, the judgment of the district court is
AFFIRMED.
Notes
. Combs mistakenly frames the issue as whether the state police complied with 18 U.S.C. § 3109 in the course of serving the search warrant on his house. However, 18 U.S.C. § 3109 governs the conduct of federal officers, not state officers such as those involved here.
United States v. Valenzuela,
. Two types of factual patterns emerge in knock and announce cases: cases where there is no knock or announcement prior to entry, a so called “no-knock” entry,
see, e.g., Wilson v. Arkansas,
. We have jurisdiction pursuant to 28 U.S.C. § 1291. We review the district court’s conclusions of law de novo and factual findings for clear error.
United States v. Hammett,
. See Methamphetamine Laboratory Identification and Hazards, United States Department of Justice, National Drug Intelligence Center, available at http://www.us-doj.gov/ndic/pubs7/7341/# hazards (brochure describing hazards involved in producing methamphetamine).
. We take care to note that “[t]he officers' concerns were not based on generalizations or stereotypes of drug dealers or narcotics investigations, but rather on particularized, articulable, and reliable information.”
U.S. v. Bynum,
