UNITED STATES v. BANKS

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31 OCTOBER TERM, 2003
Syllabus
UNITED STATES v. BANKS
certiorari to the united states court of appeals for
the ninth circuit
No. 02–473. Argued October 15, 2003—Decided December 2, 2003
When federal and local law enforcement officers went to respondent
Banks’s apartment to execute a warrant to search for cocaine, they
called out “police search warrant” and rapped on the front door hard
enough to be heard by officers at the back door, waited for 15 to 20
seconds with no response, and then broke open the door. Banks was in
the shower and testified that he heard nothing until the crash of the
door. The District Court denied his motion to suppress the drugs and
weapons found during the search, rejecting his argument that the offi-
cers waited an unreasonably short time before forcing entry in violation
of both the Fourth Amendment and 18 U. S. C. § 3109. Banks pleaded
guilty, but reserved his right to challenge the search on appeal. In
reversing and ordering the evidence suppressed, the Ninth Circuit
found, using a four-part scheme for vetting knock-and-announce entries,
that the instant entry had no exigent circumstances, making forced
entry by destruction of property permissible only if there was an
explicit refusal of admittance or a time lapse greater than the one here.
Held:
1. The officers’ 15-to-20-second wait before forcible entry satisfied the
Fourth Amendment. Pp. 35–43.
(a) The standards bearing on whether officers can legitimately
enter after knocking are the same as those for requiring or dispensing
with knock and announce altogether. This Court has fleshed out the
notion of reasonable execution on a case-by-case basis, but has pointed
out factual considerations of unusual, albeit not dispositive, signifi-
cance. The obligation to knock and announce before entering gives way
when officers have reasonable grounds to expect futility or to suspect
that an exigency, such as evidence destruction, will arise instantly upon
knocking. Richards v. Wisconsin, 520 U. S. 385, 394. Since most peo-
ple keep their doors locked, a no-knock entry will normally do some
damage, a fact too common to require a heightened justification when a
reasonable suspicion of exigency already justifies an unwarned entry.
United States v. Ramirez, 523 U. S. 65, 70–71. Pp. 35–37.
(b) This case turns on the exigency revealed by the circumstances
known to the officers after they knocked and announced, which the Gov-
ernment contends was the risk of losing easily disposable evidence.

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32 UNITED STATES v. BANKS
Syllabus
After 15 to 20 seconds without a response, officers could fairly have
suspected that Banks would flush away the cocaine if they remained
reticent. Each of Banks’s counterarguments—that he was in the
shower and did not hear the officers, and that it might have taken him
longer than 20 seconds to reach the door—rests on a mistake about the
relevant enquiry. As to the first argument, the facts known to the po-
lice are what count in judging a reasonable waiting time, and there is
no indication that they knew that Banks was in the shower and thus
unaware of an impending search. As to the second, the crucial fact is
not the time it would take Banks to reach the door but the time it would
take him to destroy the cocaine. It is not unreasonable to think that
someone could get in a position to destroy the drugs within 15 to 20
seconds. Once the exigency had matured, the officers were not bound
to learn anything more or wait any longer before entering, even though
the entry entailed some harm to the building. Pp. 37–40.
(c) This Court’s emphasis on totality analysis leads it to reject
the Government’s position that the need to damage property should
not be part of the analysis of whether the entry itself was reasonable
and to disapprove of the Ninth Circuit’s four-part vetting scheme.
Pp. 41–42.
2. The entry here also satisfied 18 U. S. C. § 3109, which permits
entry by force “if, after notice of his authority and purpose, [an of-
ficer] is refused admittance.” Because § 3109 implicates the excep-
tions to the common law knock-and-announce requirement that inform
the Fourth Amendment itself, § 3109 is also subject to an exigent circum-
stances exception, which qualifies the requirement of refusal after no-
tice, just as it qualifies the obligation to announce in the first place.
Pp. 42–43.
282 F. 3d 699, reversed.
Souter, J., delivered the opinion for a unanimous Court.
David B. Salmons argued the cause pro hac vice for the
United States. With him on the brief were Solicitor Gen-
eral Olson, Assistant Attorney General Chertoff, Deputy
Solicitor General Dreeben, and John A. Drennan.
Randall J. Roske, by appointment of the Court, 538 U. S.
943, argued the cause and filed a brief for respondent.*
*Timothy A. Baughman filed a brief for Wayne County, Michigan, as
amicus curiae urging reversal.
A brief of amici curiae was filed for Americans for Effective Law En-
forcement, Inc., et al. by Richard Weintraub, Bernard J. Farber, Wayne
W. Schmidt, and James P. Manak.

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Opinion of the Court
Justice Souter delivered the opinion of the Court.
Officers executing a warrant to search for cocaine in re-
spondent Banks’s apartment knocked and announced their
authority. The question is whether their 15-to-20-second
wait before a forcible entry satisfied the Fourth Amendment
and 18 U. S. C. § 3109. We hold that it did.
I
With information that Banks was selling cocaine at home,
North Las Vegas Police Department officers and Federal
Bureau of Investigation agents got a warrant to search his
two-bedroom apartment. As soon as they arrived there,
about 2 o’clock on a Wednesday afternoon, officers posted in
front called out “police search warrant” and rapped hard
enough on the door to be heard by officers at the back door.
Brief for United States 3 (internal quotation marks omitted).
There was no indication whether anyone was home, and after
waiting for 15 to 20 seconds with no answer, the officers
broke open the front door with a battering ram. Banks was
in the shower and testified that he heard nothing until the
crash of the door, which brought him out dripping to confront
the police. The search produced weapons, crack cocaine,
and other evidence of drug dealing.
In response to drug and firearms charges, Banks moved to
suppress evidence, arguing that the officers executing the
search warrant waited an unreasonably short time before
forcing entry, and so violated both the Fourth Amendment
and 18 U. S. C. § 3109. 1 The District Court denied the mo-
tion, and Banks pleaded guilty, reserving his right to chal-
lenge the search on appeal.
1 The statute 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.”

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Opinion of the Court
A divided panel of the Ninth Circuit reversed and ordered
suppression of the evidence found. 282 F. 3d 699 (2002). In
assessing the reasonableness of the execution of the warrant,
the panel majority set out a nonexhaustive list of “factors
that an officer reasonably should consider” in deciding when
to enter premises identified in a warrant, after knocking
and announcing their presence but receiving no express
acknowledgment:
“(a) size of the residence; (b) location of the residence;
(c) location of the officers in relation to the main living
or sleeping areas of the residence; (d) time of day;
(e) nature of the suspected offense; (f) evidence demon-
strating the suspect’s guilt; (g) suspect’s prior convic-
tions and, if any, the type of offense for which he was
convicted; and (h) any other observations triggering the
senses of the officers that reasonably would lead one
to believe that immediate entry was necessary.” Id.,
at 704.
The majority also defined four categories of intrusion after
knock and announcement, saying that the classification “aids
in the resolution of the essential question whether the entry
made herein was reasonable under the circumstances”:
“(1) entries in which exigent circumstances exist and
non-forcible entry is possible, permitting entry to be
made simultaneously with or shortly after announce-
ment; (2) entries in which exigent circumstances exist
and forced entry by destruction of property is required,
necessitating more specific inferences of exigency;
(3) entries in which no exigent circumstances exist and
non-forcible entry is possible, requiring an explicit re-
fusal of admittance or a lapse of a significant amount of
time; and (4) entries in which no exigent circumstances
exist and forced entry by destruction of property is re-
quired, mandating an explicit refusal of admittance or a

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Opinion of the Court
lapse of an even more substantial amount of time.”
Ibid.
The panel majority put the action of the officers here in the
last category, on the understanding that they destroyed the
door without hearing anything to suggest a refusal to admit
even though sound traveled easily through the small apart-
ment. The majority held the 15-to-20-second delay after
knocking and announcing to be “[in]sufficient . . . to satisfy
the constitutional safeguards.” Id., at 705.
Judge Fisher dissented, saying that the majority ought to
come out the other way based on the very grounds it
stressed: Banks’s small apartment, the loud knock and an-
nouncement, the suspected offense of dealing in cocaine, and
the time of the day. Judge Fisher thought the lapse of 15
to 20 seconds was enough to support a reasonable inference
that admittance had been constructively denied. Id., at 710.
We granted certiorari to consider how to go about apply-
ing the standard of reasonableness to the length of time
police with a warrant must wait before entering without per-
mission after knocking and announcing their intent in a fel-
ony case. 537 U. S. 1187 (2003). We now reverse.
II
There has never been a dispute that these officers were
obliged to knock and announce their intentions when execut-
ing the search warrant, an obligation they concededly hon-
ored. Despite this agreement, we start with a word about
standards for requiring or dispensing with a knock and an-
nouncement, since the same criteria bear on when the offi-
cers could legitimately enter after knocking.
The Fourth Amendment says nothing specific about for-
malities in exercising a warrant’s authorization, speaking to
the manner of searching as well as to the legitimacy of
searching at all simply in terms of the right to be “secure
. . . against unreasonable searches and seizures.” Although
the notion of reasonable execution must therefore be fleshed

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36 UNITED STATES v. BANKS
Opinion of the Court
out, we have done that case by case, largely avoiding catego-
ries and protocols for searches. Instead, we have treated
reasonableness as a function of the facts of cases so various
that no template is likely to produce sounder results than
examining the totality of circumstances in a given case; it
is too hard to invent categories without giving short shrift
to details that turn out to be important in a given instance,
and without inflating marginal ones. See, e. g., Ohio v. Rob-
inette, 519 U. S. 33, 39 (1996) (“[W]e have consistently
eschewed bright-line rules, instead emphasizing the fact-
specific nature of the reasonableness inquiry”); Ker v. Cali-
fornia, 374 U. S. 23, 33 (1963) (reasonableness not susceptible
to Procrustean application); Go-Bart Importing Co. v. United
States, 282 U. S. 344, 357 (1931) (no formula for determining
reasonableness; each case on its own facts and circum-
stances). We have, however, pointed out factual considera-
tions of unusual, albeit not dispositive, significance.
In Wilson v. Arkansas, 514 U. S. 927 (1995), we held that
the common law knock-and-announce principle is one focus
of the reasonableness enquiry; and we subsequently decided
that although the standard generally requires the police to
announce their intent to search before entering closed prem-
ises, the obligation gives way when officers “have a reason-
able suspicion that knocking and announcing their presence,
under the particular circumstances, would be dangerous or
futile, or . . . would inhibit the effective investigation of the
crime by, for example, allowing the destruction of evidence,”
Richards v. Wisconsin, 520 U. S. 385, 394 (1997). When a
warrant applicant gives reasonable grounds to expect futility
or to suspect that one or another such exigency already ex-
ists or will arise instantly upon knocking, a magistrate judge
is acting within the Constitution to authorize a “no-knock”
entry.2 And even when executing a warrant silent about
2 Some States give magistrate judges the authority to issue “no-knock”
warrants, and some do not. See, e. g., Richards v. Wisconsin, 520 U. S.
385, 396, n. 7 (1997) (collecting state statutes and cases).

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that, if circumstances support a reasonable suspicion of exi-
gency when the officers arrive at the door, they may go
straight in. Id., at 394, 396, n. 7.
Since most people keep their doors locked, entering with-
out knocking will normally do some damage, a circumstance
too common to require a heightened justification when a rea-
sonable suspicion of exigency already justifies an unwarned
entry. We have accordingly held that police in exigent cir-
cumstances may damage premises so far as necessary for a
no-knock entrance without demonstrating the suspected risk
in any more detail than the law demands for an unannounced
intrusion simply by lifting the latch. United States v. Ra-
mirez, 523 U. S. 65, 70–71 (1998). Either way, it is enough
that the officers had a reasonable suspicion of exigent
circumstances.3
III
Like Ramirez, this case turns on the significance of exi-
gency revealed by circumstances known to the officers, for
the only substantive difference between the two situations
goes to the time at which the officers reasonably anticipated
some danger calling for action without delay.4 Whereas the
3 The standard for a no-knock entry stated in Richards applies on rea-
sonable suspicion of exigency or futility. Because the facts here go to
exigency, not futility, we speak of that alone.
4 Ramirez and Richards v. Wisconsin, 520 U. S. 385 (1997), our cases
addressing the role of exigency in assessing the reasonableness of a no-
knock entry, involved searches by warrant for evidence of a felony, as does
this case. In a different context governed by the Fourth Amendment, we
have held that the risk of losing evidence of a minor offense is insufficient
to make it reasonable to enter a dwelling to make a warrantless arrest.
See Welsh v. Wisconsin, 466 U. S. 740 (1984). Courts of Appeals have
applied Welsh to warrantless entries simply to search for evidence, consid-
ering the gravity of the offense in determining whether exigent circum-
stances exist. See, e. g., United States v. Aquino, 836 F. 2d 1268, 1271–
1273 (CA10 1988); United States v. Clement, 854 F. 2d 1116, 1120 (CA8
1988) (per curiam). We intimate nothing here about such warrantless
entry cases. Nor do we express a view on the significance of the exist-
ence of a warrant in evaluating whether exigency justifies action in

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Opinion of the Court
Ramirez Magistrate Judge found in advance that the custom-
ary warning would raise an immediate risk that a wanted
felon would elude capture or pose a threat to the officers, see
id., at 68, here the Government claims that a risk of losing
evidence arose shortly after knocking and announcing. Al-
though the police concededly arrived at Banks’s door without
reasonable suspicion of facts justifying a no-knock entry,
they argue that announcing their presence started the clock
running toward the moment of apprehension that Banks
would flush away the easily disposable cocaine, prompted by
knowing the police would soon be coming in. While it was
held reasonable for the police in Ramirez to enter forcibly
upon arrival, the Government argues it was equally reason-
able for the officers to go in with force here as soon as the
danger of disposal had ripened.
Banks does not, of course, deny that exigency may develop
in the period beginning when officers with a warrant knock
to be admitted, and the issue comes down to whether it was
reasonable to suspect imminent loss of evidence after the 15
to 20 seconds the officers waited prior to forcing their way.
Though we agree with Judge Fisher’s dissenting opinion that
this call is a close one, 282 F. 3d, at 707, we think that after
15 or 20 seconds without a response, police could fairly sus-
pect that cocaine would be gone if they were reticent any
longer. Courts of Appeals have, indeed, routinely held simi-
lar wait times to be reasonable in drug cases with similar
facts including easily disposable evidence (and some courts
have found even shorter ones to be reasonable enough).5
knock-and-announce cases when the reason for the search is a minor
offense.
5 Several Courts of Appeals have explicitly taken into account the risk
of disposal of drug evidence as a factor in evaluating the reasonableness
of waiting time. See, e. g., United States v. Goodson, 165 F. 3d 610, 612,
614 (CA8 1999) (holding a 20-second wait after a loud announcement at a
one-story ranch reasonable); United States v. Spikes, 158 F. 3d 913, 925–
927 (CA6 1998) (holding a 15-to-30-second wait in midmorning after a loud
announcement reasonable); United States v. Spriggs, 996 F. 2d 320, 322–

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Opinion of the Court
A look at Banks’s counterarguments shows why these
courts reached sensible results, for each of his reasons for
saying that 15 to 20 seconds was too brief rests on a mistake
about the relevant enquiry: the fact that he was actually in
the shower and did not hear the officers is not to the point,
and the same is true of the claim that it might have taken
him longer than 20 seconds if he had heard the knock and
headed straight for the door. As for the shower, it is enough
to say that the facts known to the police are what count in
judging reasonable waiting time, cf., e. g., Graham v. Connor,
490 U. S. 386, 396 (1989) (“The ‘reasonableness’ of a particu-
lar use of force must be judged from the perspective of a
reasonable officer on the scene, rather than with the 20/20
vision of hindsight”), and there is no indication that the po-
lice knew that Banks was in the shower and thus unaware
of an impending search that he would otherwise have tried
to frustrate.
And the argument that 15 to 20 seconds was too short for
Banks to have come to the door ignores the very risk that
justified prompt entry. True, if the officers were to justify
their timing here by claiming that Banks’s failure to admit
them fairly suggested a refusal to let them in, Banks could
at least argue that no such suspicion can arise until an occu-
323 (CADC 1993) (holding a 15-second wait after a reasonably audible
announcement at 7:45 a.m. on a weekday reasonable); United States v.
Garcia, 983 F. 2d 1160, 1168 (CA1 1993) (holding a 10-second wait after a
loud announcement reasonable); United States v. Jones, 133 F. 3d 358, 361–
362 (CA5 1998) (per curiam) (relying specifically on the concept of exi-
gency, holding a 15-to-20-second wait reasonable). See also United States
v. Chavez-Miranda, 306 F. 3d 973, 981–982, n. 7 (CA9 2002) (“Banks ap-
pears to be a departure from our prior decisions. . . . [W]e have found a
10 to 20 second wait to be reasonable in similar circumstances, albeit when
the police heard sounds after the knock and announcement”); United
States v. Jenkins, 175 F. 3d 1208, 1215 (CA10 1999) (holding a 14-to-20-
second wait at 10 a.m. reasonable); United States v. Markling, 7 F. 3d
1309, 1318–1319 (CA7 1993) (holding a 7-second wait at a small motel room
reasonable when officers acted on a specific tip that the suspect was likely
to dispose of the drugs).

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Opinion of the Court
pant has had time to get to the door,6 a time that will vary
with the size of the establishment, perhaps five seconds to
open a motel room door, or several minutes to move through
a townhouse. In this case, however, the police claim exigent
need to enter, and the crucial fact in examining their actions
is not time to reach the door but the particular exigency
claimed. On the record here, what matters is the opportu-
nity to get rid of cocaine, which a prudent dealer will keep
near a commode or kitchen sink. The significant circum-
stances include the arrival of the police during the day, when
anyone inside would probably have been up and around, and
the sufficiency of 15 to 20 seconds for getting to the bathroom
or the kitchen to start flushing cocaine down the drain.
That is, when circumstances are exigent because a pusher
may be near the point of putting his drugs beyond reach, it
is imminent disposal, not travel time to the entrance, that
governs when the police may reasonably enter; since the
bathroom and kitchen are usually in the interior of a dwell-
ing, not the front hall, there is no reason generally to peg
the travel time to the location of the door, and no reliable
basis for giving the proprietor of a mansion a longer wait
than the resident of a bungalow, or an apartment like
Banks’s. And 15 to 20 seconds does not seem an unrealistic
guess about the time someone would need to get in a position
to rid his quarters of cocaine.
Once the exigency had matured, of course, the officers
were not bound to learn anything more or wait any longer
before going in, even though their entry entailed some harm
to the building. Ramirez held that the exigent need of law
enforcement trumps a resident’s interest in avoiding all
property damage, see 523 U. S., at 70–71, and there is no
reason to treat a post-knock exigency differently from the
no-knock counterpart in Ramirez itself.
6 It is probably unrealistic even on its own terms. The apartment was
“small,” 282 F. 3d 699, 704 (CA9 2002), and a man may walk the length of
today’s small apartment in 15 seconds.

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Opinion of the Court
IV
Our emphasis on totality analysis necessarily rejects posi-
tions taken on each side of this case. Ramirez, for example,
cannot be read with the breadth the Government espouses,
as “reflect[ing] a general principle that the need to damage
property in order to effectuate an entry to execute a search
warrant should not be part of the analysis of whether the
entry itself was reasonable.” Brief for United States 18;
Reply Brief for United States 4. At common law, the
knock-and-announce rule was traditionally “justified in part
by the belief that announcement generally would avoid ‘the
destruction or breaking of any house . . . by which great
damage and inconvenience might ensue.’ ” Wilson, 514
U. S., at 935–936 (quoting Semayne’s Case, 5 Co. Rep. 91a,
91b, 77 Eng. Rep. 194, 196 (K. B. 1603)). One point in mak-
ing an officer knock and announce, then, is to give a person
inside the chance to save his door. That is why, in the case
with no reason to suspect an immediate risk of frustration
or futility in waiting at all, the reasonable wait time may
well be longer when police make a forced entry, since they
ought to be more certain the occupant has had time to an-
swer the door. It is hard to be more definite than that, with-
out turning the notion of a reasonable time under all the
circumstances into a set of sub-rules as the Ninth Circuit has
been inclined to do. Suffice it to say that the need to dam-
age property in the course of getting in is a good reason to
require more patience than it would be reasonable to expect
if the door were open. Police seeking a stolen piano may
be able to spend more time to make sure they really need
the battering ram.
On the other side, we disapprove of the Court of Appeals’s
four-part scheme for vetting knock-and-announce entries.
To begin with, the demand for enhanced evidence of exigency
before a door can reasonably be damaged by a warranted
no-knock intrusion was already bad law before the Court of
Appeals decided this case. In Ramirez (a case from the

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Ninth Circuit), we rejected an attempt to subdivide felony
cases by accepting “mild exigency” for entry without prop-
erty damage, but requiring “more specific inferences of exi-
gency” before damage would be reasonable. 523 U. S., at
69–71 (internal quotation marks omitted). The Court of Ap-
peals did not cite Ramirez.
Nor did the appeals court cite United States v. Arvizu, 534
U. S. 266 (2002) (again, from the Ninth Circuit). There, we
recently disapproved a framework for making reasonable
suspicion determinations that attempted to reduce what the
Circuit described as “troubling . . . uncertainty” in reason-
ableness analysis, by “describ[ing] and clearly delimit[ing]”
an officer’s consideration of certain factors. Id., at 272, 275
(internal quotation marks omitted). Here, as in Arvizu, the
Court of Appeals’s overlay of a categorical scheme on the
general reasonableness analysis threatens to distort the “to-
tality of the circumstances” principle, by replacing a stress
on revealing facts with resort to pigeonholes. Id., at 274
(internal quotation marks omitted). Attention to cocaine
rocks and pianos tells a lot about the chances of their respec-
tive disposal and its bearing on reasonable time. Instruc-
tions couched in terms like “significant amount of time,” and
“an even more substantial amount of time,” 282 F. 3d, at 704,
tell very little.
V
Last, there is Banks’s claim that the entry violated 18
U. S. C. § 3109. Ramirez held that the result should be the
same under the Fourth Amendment and § 3109, permitting
an officer to enter by force “if, after notice of his authority
and purpose, he is refused admittance.” We explained the
statute’s “ ‘requirement of prior notice . . . before forcing
entry . . . [as] codif[ying] a tradition embedded in Anglo-
American law,’ ” 523 U. S., at 72 (quoting Miller v. United
States, 357 U. S. 301, 313 (1958)); see also Sabbath v. United
States, 391 U. S. 585, 591, n. 8 (1968), and we held that § 3109
implicates the exceptions to the common law knock-and-

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Opinion of the Court
announce requirement that inform the Fourth Amendment
itself, 523 U. S., at 73. The upshot is that § 3109 is subject
to an exigent circumstances exception, ibid., which qualifies
the requirement of refusal after notice, just as it qualifies the
obligation to announce in the first place. Absent exigency,
the police must knock and receive an actual refusal or wait
out the time necessary to infer one. But in a case like this,
where the officers knocked and announced their presence,
and forcibly entered after a reasonable suspicion of exigency
had ripened, their entry satisfied § 3109 as well as the Fourth
Amendment, even without refusal of admittance.
The judgment of the Court of Appeals is reversed.
So ordered.