                   FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


UNITED STATES OF AMERICA,                 No. 11-50213
          Plaintiff-Appellant,
                                         D.C. No.
              v.                      2:10-cr-00863-
                                         SVW-8
JOHN MICHAEL UNDERWOOD,
         Defendant-Appellee.               OPINION



      Appeal from the United States District Court
          for the Central District of California
      Stephen V. Wilson, District Judge, Presiding

              Argued and Submitted
       December 6, 2012—Pasadena, California

                   Filed August 6, 2013

       Before: Harry Pregerson, John T. Noonan,
         and Richard A. Paez, Circuit Judges.

              Opinion by Judge Pregerson
2               UNITED STATES V. UNDERWOOD

                           SUMMARY*


                          Criminal Law

    Affirming the district court’s order suppressing drug-
trafficking evidence found during a search of the defendant’s
home, the panel held that the state warrant that authorized the
search was not supported by probable cause, and the good
faith exception to the exclusionary rule was not met.


                            COUNSEL

Mack E. Jenkins, Assistant United States Attorney, Los
Angeles, California, for Plaintiff-Appellant.

Donald M. Ré, Los Angeles, California, for Defendant-
Appellee.


                             OPINION

PREGERSON, Circuit Judge:

    Appellee John Underwood was charged with conspiracy
to possess and distribute controlled substances under
21 U.S.C. §§ 841 and 846, and possession with intent to
distribute cocaine and ecstasy under 21 U.S.C. § 841. In
district court Underwood moved to suppress drug trafficking


  *
    This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
              UNITED STATES V. UNDERWOOD                    3

evidence found during a search of his home, arguing that the
state warrant that authorized the search lacked probable cause
and the good faith exception to the exclusionary rule did not
apply. District Judge Stephen Wilson granted Underwood’s
motion to suppress. The United States appeals. We have
jurisdiction under 18 U.S.C. § 3731, and we affirm.

                    I. BACKGROUND

   A. Federal Warrants & Underwood’s Arrest

    Between January and July 2010, the Drug Enforcement
Administration (“DEA”) and the Beverly Hills Police
Department conducted a wiretap investigation into a
suspected drug trafficking organization headed by
Underwood’s co-defendant, Jimmy Luong. The investigation
revealed that Luong’s drug trafficking organization (“Luong
DTO”) was likely distributing hundreds of thousands of pills
of ecstasy per week.

    In April 2010, agents followed Luong and Tony Barrera,
another one of Underwood’s co-defendants, from Barrera’s
residence to a Home Depot parking lot. There, agents
observed Luong and Barrera meeting with Underwood and
transferring two large unmarked crates from Underwood’s
vehicle to their own. Agents used surveillance to track the
two crates to a Luong DTO stash house where the crates were
subsequently seized and found to contain thousands of
ecstasy pills.

    On July 22, 2010 federal agents, assisted by local law
enforcement including Los Angeles Police Department
Detective James Kaiser, simultaneously executed federal
arrest warrants for seventeen suspected co-conspirators of the
4            UNITED STATES V. UNDERWOOD

Luong DTO and federal search warrants for fifteen
residences, stash houses, and vehicles. DEA Agent Peter
Johnson prepared the 102-page affidavit in support of the
federal warrants. Underwood does not contest the affidavit
or the execution of the federal warrants.

    One of the federal search warrants was executed at a
house believed to be Underwood’s, on Cantrece Lane in
Cerritos, California. When the officers arrived, they found
only Underwood’s mother, who told them Underwood
actually lived on Mansa Drive in La Mirada, California. A
search of the Cantrece Lane house did not reveal any
evidence of drug trafficking.

    Later that day, at the Mansa Drive house, agents arrested
Underwood and conducted a protective sweep of the house.
During that sweep, agents observed a clear zip-lock bag
containing a personal-use amount of marijuana on a table in
the living room. Following Underwood’s refusal to consent
to a full search of the house, DEA Agent Johnson instructed
local officers to obtain a state search warrant for the Mansa
Drive house as soon as possible. LAPD Detective Kaiser was
assigned the task of securing the warrant. To assist Kaiser
with the task, Johnson emailed Kaiser a summary of the case
against Underwood based on the federal affidavit and an
explanation of why Johnson believed evidence would be
found at the Mansa Drive house.

    B. State Affidavit & Search Warrant

    Underwood challenges the affidavit supporting the state
search warrant for the Mansa Drive house. In the state
affidavit, Kaiser first listed the evidence to be seized,
including: records of drug transactions, bank account
              UNITED STATES V. UNDERWOOD                       5

records, supplier lists, phones, drugs such as ecstasy, drug
paraphernalia, currency over $500, personal records such as
bills, photographs and videos involving drugs, and firearms.

     In a section titled “Statement of Probable Cause for
Search Warrant,” Kaiser listed his narcotics training and
experience. In the next section, titled “Narrative,” Kaiser
began by stating, “On 7-15-10, I, Detective Kaiser, learned
the following from US Drug Enforcement Agent Peter
Johnson of the LA Office, Group 4:.” The next four and a
half pages are in a different font, and are copied nearly
verbatim from the federal affidavit prepared by Johnson.
Personal experience and opinion statements in these four and
a half pages, such as “I believe,” “my surveillance
observations” and “based on my training, experience,” are all
initially made by Johnson in the federal affidavit. Kaiser
never stated that he was copying directly from Johnson’s
affidavit, so it is not clear from the affidavit whether Kaiser
meant to adopt these statements as his own or whether he
meant to quote Johnson. Kaiser declared later, however, that
the statements should be read as from Johnson’s perspective
and based upon Johnson’s personal knowledge. The narrative
begins:

        On July 15, 2010, United States Magistrate
        Judge Victor Kenton signed a federal arrest
        warrant for John Michael Underwood
        (“Underwood”) and a federal search warrant
        for Cantrece Lane, Cerritos, CA. Underwood
        is a courier for a multi-hundred thousand pill
        MDMA1 drug trafficking organization

  1
    MDMA is short for methylenedioxymethamphetamine, the chemical
name for ecstasy.
6             UNITED STATES V. UNDERWOOD

       (“Luong DTO”). On April 14, 2010, Drug
       Enforcement Administration (“DEA”) Special
       Agents and Beverly Hills Police Department
       (“BHPD”) Detectives observed Underwood
       deliver two wooden crates to known co-
       conspirators Jimmy Luong (“Luong”) and
       Tony Barrera (“Barrera”). Based on the other
       seizures in the investigation, I believe the
       crates contained approximately 260,000 pills
       of MDMA.

The affidavit does not include any factual details of “the other
seizures” to support Johnson’s belief that the crates contained
260,000 pills of ecstasy. The only factual support for the
conclusion that Underwood is a “courier” for the Luong DTO
is that agents observed Underwood deliver two wooden crates
to Luong and Barrera.

    The narrative goes on to provide Johnson’s opinions
about the general behavior of drug traffickers based on his
training and experience, including that: drug trafficking is a
“continuing criminal activity taking place over months, and
often years”; traffickers “commonly ‘front’ (provide . . . on
consignment) illegal controlled substances to their clients and
thus keep some types of records concerning monies owed and
payments made”; and traffickers often keep these records at
their residences. The affidavit notes that, based on
“intercepted conversations over TT #1–4, #6–7 and my
surveillance observations, I believe that most of the higher
level members of the LUONG DTO have been given
MDMA” through “fronting” arrangements. The affidavit
does not provide factual details about the “intercepted
conversations” or Johnson’s “surveillance observations,” or
explain what “TT #1–4, #6–7” means. Johnson’s affidavit
              UNITED STATES V. UNDERWOOD                      7

from which Kaiser apparently copied explains that “TT” is an
abbreviation for “Target Telephones” and lists the target
telephone numbers and the suspected co-conspirator who
used each number. This information, however, was omitted
from Kaiser’s affidavit.

    Finally, following the four and a half pages copied from
Johnson’s federal affidavit, Kaiser described his role in the
execution of the federal search warrant and Underwood’s
arrest at the Mansa Drive house. Regarding the finding of
marijuana, Kaiser stated: “During the [protective] sweep,
Detective Davis saw an amount of what appeared to be
marijuana in a zip loc baggie on a table in the living room.”

    Kaiser did not attach the federal affidavit to his affidavit
for the state search warrant for Mansa Drive. Kaiser claims
that, because the state warrant was “based on the same
underlying probable cause of the federal warrant” and
because he referenced the federal warrants in his affidavit, he
believed the probable cause stated by the federal affidavit
“carried over.”

    Based on Kaiser’s affidavit, a Los Angeles Superior Court
judge issued a search warrant for the Mansa Drive house on
July 22, 2010. The judge did not ask to review the federal
affidavit referenced in Kaiser’s state affidavit. The search
pursuant to the state warrant resulted in the seizure of thirty-
three kilograms of cocaine, $417,000 in cash, 104 ecstasy
pills, packaging material, a money counter, and a “pay/owe”
sheet.
8             UNITED STATES V. UNDERWOOD

    C. Procedural History

    Underwood was charged with conspiracy to possess and
distribute controlled substances in violation of 21 U.S.C.
§§ 841 and 846, and with possession with intent to distribute
cocaine and ecstasy in violation of 21 U.S.C. § 841.
Underwood filed a motion to suppress the evidence seized
from his Mansa Drive house. Underwood argued that the
affidavit supporting the state search warrant for Mansa Drive
lacked probable cause. Underwood also argued the good
faith exception to the exclusionary rule established in United
States v. Leon, 468 U.S. 897 (1984) did not apply because the
affidavit was a “bare bones” affidavit that lacked indicia of
probable cause.

    District Judge Stephen Wilson granted the motion to
suppress. In a lengthy, scholarly order, Judge Wilson
concluded that the affidavit supporting the state search
warrant lacked probable cause because the affidavit set forth
mostly conclusory allegations and only two facts—
Underwood’s delivery of undescribed crates to Luong three
months before the warrant application and an observation of
a personal-use amount of marijuana in Underwood’s home.
The district court further concluded that the good faith
exception did not apply because the affidavit did not make a
colorable showing of probable cause, and was thus a bare
bones affidavit. The United States timely filed a Notice of
Appeal.

              II. STANDARD OF REVIEW

    We review a district court’s rulings on motions to
suppress and the validity of search warrants de novo. United
States v. Crews, 502 F.3d 1130, 1135 (9th Cir. 2007); United
               UNITED STATES V. UNDERWOOD                       9

States v. Jones, 286 F.3d 1146, 1150 (9th Cir. 2002). We
give “great deference” to an issuing judge’s finding that
probable cause supports a warrant and review such findings
for clear error. United States v. Krupa, 658 F.3d 1174, 1177
(9th Cir. 2011). We review a district court’s application of
the good faith exception to the exclusionary rule de novo.
United States v. Luong, 470 F.3d 898, 902 (9th Cir. 2006).

                     III. DISCUSSION

    The government appeals the district court’s grant of
Underwood’s motion to suppress, arguing that (1) the warrant
was supported by probable cause; and (2) if the warrant was
not supported by probable cause, the good faith exception
applies. We are not persuaded by these arguments.

    A. Probable Cause

    A search warrant is supported by probable cause if the
issuing judge finds that, “given all the circumstances set forth
in the affidavit before him . . . there is a fair probability that
contraband or evidence of a crime will be found in a
particular place.” Illinois v. Gates, 462 U.S. 213, 238 (1983).
A reviewing court should find that probable cause is not met
when the issuing judge lacked a “‘substantial basis for . . .
conclud[ing]’ that probable cause existed.” Id. at 238–39
(quoting Jones v. United States, 362 U.S. 257, 271 (1960)).

     Conclusions of the affiant unsupported by underlying
facts cannot be used to establish probable cause. See United
States v. Cervantes, 703 F.3d 1135, 1139–40 (9th Cir. 2012)
(affording little if any weight to detective’s conclusory
statement that, based on his training and experience, the box
in defendant’s possession came from a suspected narcotics
10            UNITED STATES V. UNDERWOOD

stash house); see also Spinelli v. United States, 393 U.S. 410,
418 (1969); Gates, 462 U.S. at 241. An affidavit must recite
underlying facts so that the issuing judge can draw his or her
own reasonable inferences and conclusions; it is these facts
that form the central basis of the probable cause
determination. United States v. Ventresca, 380 U.S. 102,
108–09 (1965); Giordenello v. United States, 357 U.S. 485,
486 (1958) (“The Commissioner must judge for himself the
persuasiveness of the facts relied on by a complaining officer
to show probable cause. He should not accept without
question the complainant’s mere conclusion that the person
whose arrest is sought has committed a crime.”) (emphasis
added); United States v. Rubio, 727 F.2d 786, 795 (9th Cir.
1983) (“The magistrate must be provided with sufficient facts
from which he may draw the inferences and form the
conclusions necessary to a determination of probable cause.”)
(emphasis added); United States v. Dubrofsky, 581 F.2d 208,
212 (9th Cir. 1978) (“A search warrant may not rest upon
mere affirmance or belief without disclosure of supporting
facts or circumstances.”).

    Expert opinion may also be considered in the totality of
the circumstances analysis for probable cause. See, e.g,
United States v. Gil, 58 F.3d 1414, 1418 (9th Cir. 1995). As
we held in United States v. Weber, however, “if the
government presents expert opinion about the behavior of a
particular class of persons, for the opinion to have any
relevance, the affidavit must lay a foundation which shows
that the person subject to the search is a member of the class.”
923 F.2d 1338, 1345 (9th Cir. 1990).

    In Weber, we concluded that an affidavit supporting a
search warrant of the defendant’s house lacked probable
cause where it contained only the following information: (1)
              UNITED STATES V. UNDERWOOD                     11

an allegation that two years previously, the defendant had
received advertising material that was “apparently” child
pornography; (2) an allegation that the defendant recently
ordered materials in response to a child pornography
advertisement created by the government; and (3) expert
opinion about the habits of “child molesters,” “pedophiles,”
and “child pornography collectors.” Id. at 1344–46. The
affidavit neither defined child molester, pedophile, or child
pornography collector. Id. at 1341. We found that the
ordering of child pornography materials from the government
advertisement did not make the defendant a child
pornography collector when the affidavit failed to define the
term. Id. at 1345–46. Moreover, the affidavit failed to assert
let alone set forth facts to prove that the defendant was a
member of any of the three groups. Id. For this reason, we
concluded that the opinion about child molesters, pedophiles,
and child pornography collectors was “foundationless.” Id.
at 1345. Therefore, the expert opinion could not be used to
support probable cause. Id. at 1345–46. Finally, we found
that the affidavit did not support a conclusion that child
pornography materials would be found at the defendant’s
house. Id. We reasoned that reaching such a conclusion from
the factual allegations in the affidavit required that we draw
too many inferences: “[e]ach of these inferences standing
alone may be reasonable. But with each succeeding
inference, the last reached is less and less likely to be true.”
Id. at 1345.

    When viewed in the totality of the circumstances, the
affidavit here fails to provide a sufficient basis for probable
cause. Like the affidavit in Weber, the affidavit in
Underwood’s case includes only two facts, foundationless
expert opinion, and conclusory allegations.
12            UNITED STATES V. UNDERWOOD

    First, the affidavit describes Detective Davis’s
observation of a baggie of a personal-use amount of
marijuana at Underwood’s Mansa Drive home during the
protective sweep. Although this description is a sufficiently
detailed factual allegation, it lacks a nexus with ecstasy
trafficking and therefore does not support the conclusion that
Underwood is a ecstasy trafficker. Both the amount and the
type of drug observed are important. As Kaiser’s affidavit
explained, drug traffickers often keep evidence of their
trafficking activities—such as their inventory of drugs, cash
from sales, and records from sales—at their homes. Thus, if
police had observed a large amount of drugs in Underwood’s
home, especially in combination with a large amount of cash
or apparent drug business records, this would support the
conclusion that Underwood is a drug trafficker. But all that
police observed was a personal-use amount of marijuana in
Underwood’s home, which supports only the inference that
Underwood is a marijuana user. This evidence does not
indicate that Underwood uses ecstasy, a drug entirely
different from marijuana, and it certainly does not indicate
that he is an ecstasy trafficker. See United States v. Vizcarra-
Martinez, 66 F.3d 1006, 1016 n.8 (9th Cir. 1995) (holding
that “evidence of drug use or mere possession cannot be used
to prove that the defendant possessed a different type of drug
with intent to distribute” because the relationship between the
two are so attenuated). Thus, the personal-use amount of
marijuana observed in Underwood’s home fails to support the
conclusion that Underwood is a courier for an ecstasy
trafficking organization or that evidence of such trafficking
would be found at Underwood’s home.

    Second, the fact that agents observed Underwood deliver
two wooden crates to Luong and Barrera on one occasion
three months before the warrant application hardly supports
              UNITED STATES V. UNDERWOOD                    13

the conclusion that Underwood is a drug courier working for
Luong. The affidavit does not make any other factual
assertions indicating that Underwood made other deliveries
to Luong or Barrera or even had contact with Luong or
Barrera at any other time. Moreover, the affidavit neither
includes a description of the crates, nor any other facts that
would indicate that the crates contained ecstasy. We afford
little to no weight to the statement, “Based on other seizures
in this investigation, I believe the crates contained
approximately 260,000 pills of MDMA.” This statement
adds the general fact that the investigation resulted in
seizures. Unlike in the federal affidavit, however, the
statement is not accompanied by an explanation of the nature
of the seizures—for example, what was seized and where the
seizures took place. This statement is thus a bare conclusion
because it provides no underlying facts about the seizures
from which the issuing judge could draw his or her own
conclusion about how, if at all, the seizures indicate that the
two crates contained ecstasy.

    Third, the affidavit contained Johnson’s beliefs about
drug traffickers’ general habits based on Johnson’s
experience and training, including that drug traffickers often
keep records from drug transactions at their residences. In
Weber, even where the affidavit alleged that the defendant
had ordered child pornography in the recent past, we found
this fact did not support the conclusion that defendant was a
“child pornography collector” because the affidavit failed to
define the term. 923 F.2d at 1345–46. Here, the affidavit not
only fails to define “drug trafficker” but it also provides no
facts to support the conclusion that Underwood is in the
business of buying and selling ecstasy. Moreover, the
affidavit does not even assert that Underwood is a drug
trafficker. Instead, the affidavit describes Underwood as a
14            UNITED STATES V. UNDERWOOD

“courier.” As District Judge Stephen Wilson explained, the
two terms have different meanings: while a trafficker is
someone who is in the business of buying and selling items,
a courier is “one who merely delivers items (in this context,
contraband) but does not typically trade, buy, or sell the items
being delivered.” Thus, Kaiser’s conclusions about drug
traffickers—which were based exclusively on Johnson’s
opinions—are foundationless as to Underwood. Hence, they
cannot be used to support a finding of fair probability that
drug trafficking evidence would be found at Underwood’s
home.

    Detective Kaiser’s statement that a federal warrant had
previously issued in the case for a different residence does not
add any indicia of probable cause to the state affidavit. First,
neither the federal warrant nor the 102-page federal affidavit
were attached to the state affidavit. In this situation, the mere
assertion of the prior issuance of the federal warrant for a
different property should not be treated as a “supporting fact
or circumstance” for probable cause purposes. The Supreme
Court stated in Leon that in issuing a warrant, a judge must
“perform his neutral and detached function and not serve
merely as a rubber stamp for the police.” 468 U.S. at 914; see
also Ventresca, 380 U.S. at 108–09 (“Recital of some of the
underlying circumstances in the affidavit is essential if the
magistrate is to perform his detached function and not serve
merely as a rubber stamp for the police.”). If we allow judges
to rely on the mere assertion that another judge previously
issued a warrant in the case without also relying on that other
judge’s analysis or supporting facts, we would encourage
judges to rubber-stamp the conclusions of law enforcement
and of each other. Second, and more importantly, this case
concerns two different affidavits. The unattached federal
affidavit that supported the previously issued federal warrant
              UNITED STATES V. UNDERWOOD                     15

is entirely different from the state affidavit at issue here.
While the federal affidavit detailed the federal investigation
of Underwood and his co-defendants in 102 pages, the
affidavit in this case was specific to Underwood and, as
explained above, contained mostly conclusory allegations and
only two facts, one of which—the personal-use amount of
marijuana—was entirely distinct from the federal warrant.
Thus, the prior issuance of a federal warrant based on
different and more complete information adds no indicia of
probable cause to the state affidavit.

    Finally, the rest of the affidavit is made up of conclusory
allegations. These allegations are either entirely unsupported
by facts or are explained as based on “other seizures,”
“intercepted conversations over TT #1–4, #6–7” or “my
surveillance observations,” meaning Johnson’s surveillance
observations. As explained above, these vague explanations
add little if any support because they do not include
underlying facts that the issuing judge may use to evaluate the
affiant’s reasoning or to draw his or her own inferences. For
example, the affidavit does not explain who was being
surveilled, what was observed, whom the intercepted
conversations were apparently between, or what was said
during those conversations. From the allegations as written,
the issuing judge would have to trust Kaiser and DEA Agent
Johnson that the information from the intercepted
conversations and surveillance supports their conclusions.
Thus, we see these allegations as essentially conclusory
statements, and afford them little if any weight in the
probable cause analysis.

    When viewed in the totality of the circumstances, the
affidavit fails to establish probable cause. The affidavit does
not give a reasonable judge sufficient basis to find that it was
16            UNITED STATES V. UNDERWOOD

fairly probable that Underwood was an ecstasy courier or that
evidence of ecstasy trafficking would be found at
Underwood’s house. To conclude from the affidavit that
Underwood is a courier for the Luong DTO requires either
blind trust in Johnson’s conclusory statements or the drawing
of too many inferences. One would have to infer from the
crate delivery—the only factual allegation with a nexus to the
crime charged—that: (1) Luong and Barrera are conspirators
in a drug trafficking organization, (2) the crate contained
ecstasy, and (3) Underwood knew or had reason to know the
crates contained ecstasy. Further, the affidavit lacks any
basis from which to conclude that any of the evidence listed
in the affidavit would be found at Mansa Drive, given that
expert opinion on drug traffickers keeping such evidence at
their homes was foundationless. For these reasons, the
resulting search warrant for Mansa Drive is defective under
the Fourth Amendment.

     B. Good Faith Exception

    If a warrant lacks probable cause, evidence obtained
during its execution should generally be suppressed under the
exclusionary rule. Mapp v. Ohio, 367 U.S. 643, 655 (1961);
Weeks v. United States, 232 U.S. 383, 393 (1914). While the
Supreme Court has articulated various rationales for the
exclusionary rule, the rule’s primary purpose has been to
deter law enforcement from carrying out unconstitutional
searches and seizures. Although the exclusionary rule is
often framed as a nuisance to law enforcement, we view it as
a promoter of police professionalism and education. See
Herring v. United States, 555 U.S. 135, 156 n.6 (2009)
(Ginsburg, J., dissenting) (noting that “professionalism is a
sign of the exclusionary rule’s efficacy . . . .”). The
exclusionary rule has helped police more effectively secure
              UNITED STATES V. UNDERWOOD                   17

good evidence without violating the law and the rights of
American citizens.        See, e.g., Myron Orfield, The
Exclusionary Rule and Deterrence: An Empirical Study of
Chicago Narcotics Officers, 54 U. Chi. L. Rev. 1016,
1036–40 (Summer 1987); Stephen H. Sachs, The
Exclusionary Rule: A Prosecutor’s Defense, 1 Crim. Just.
Ethics 28, 31–32 (1982). The rule has also improved the
quality of police training, education, and case reporting. See
Wayne LaFave, Search and Seizure: A Treatise on the Fourth
Amendment § 1.2(b) at 33 (4th ed. 2004); Yale Kamisar,
Public Safety v. Individual Liberties: Some “Facts” and
“Theories”, 53 J. Crim. L. Criminology & Police Sci. 171,
179–81 (1962); Orfield, supra, at 1028, 1040; Sachs, supra,
at 31–32.

    Despite the benefits of the exclusionary rule, significant
exceptions to the rule have developed. Under these
exceptions, evidence seized pursuant to a defective warrant
will not be suppressed. One such exception is the “good
faith” exception established by Leon, which is satisfied if an
officer acts “in objectively reasonable reliance” on the
warrant. 468 U.S. at 922. To determine whether the officer
acted in objectively reasonable reliance, “all of the
circumstances—including whether the warrant application
had previously been rejected by a different magistrate—may
be considered.” Id. at 922 n.23; see also Messerschmidt v.
Millender, 132 S. Ct. 1235, 1249–50 (2012) (where the
Supreme Court considered whether an officer had a superior
review the challenged affidavit to determine if the officer
acted in reasonable reliance, thus clarifying that courts can
look beyond the four corners of the affidavit to consider
extrinsic factors in the good faith analysis). The burden of
demonstrating good faith rests with the government. United
States v. Kow, 58 F.3d 423, 428 (9th Cir. 1995).
18            UNITED STATES V. UNDERWOOD

     The Court in Leon identified four situations that per se
fail to satisfy the good faith exception. In these situations,
“the officer will have no reasonable grounds for believing
that the warrant was properly issued.” 468 U.S. at 922–23.
The four situations are: (1) where the affiant recklessly or
knowingly placed false information in the affidavit that
misled the issuing judge; (2) where the judge “wholly
abandon[s] his [or her] judicial role”; (3) where the affidavit
is “so lacking in indicia of probable cause as to render official
belief in its existence entirely unreasonable”; and (4) where
the warrant is “so facially deficient—i.e., in failing to
particularize the place to be searched or the things to be
seized—that the executing officers cannot reasonably
presume it to be valid.” Id. (internal quotations omitted). If
any of these four situations apply, as we explained in United
States v. Luong, we “need not inquire further” and can
conclude that the good faith exception to the exclusionary
rule does not apply. 479 F.3d at 905. The third situation,
which we also refer to as a “bare bones” affidavit, applies in
this case.

    An affidavit is so lacking in indicia of probable cause, or
bare bones, when it fails to provide a colorable argument for
probable cause. United States v. Hove, 848 F.2d 137, 139–40
(9th Cir. 1988). A colorable argument is made when
“thoughtful and competent judges” could disagree that
probable cause does not exist. Id. at 139 (internal quotations
omitted). Here, we agree with Underwood that the affidavit
submitted by Kaiser in support of the state search warrant for
Underwood’s Mansa Drive house was so deficient as to
render official belief in its existence entirely unreasonable.
Reasonable judges could not disagree that probable cause to
search for drug trafficking evidence at Mansa Drive did not
exist.
              UNITED STATES V. UNDERWOOD                    19

    As discussed in part A, the affidavit fails to set forth a
sufficient factual basis for the conclusion that Underwood is
a courier for an ecstasy trafficking organization. The only
fact with any degree of support for this conclusion is the
observation that, three months before the warrant application
for Mansa Drive, Underwood delivered two wooden crates to
Luong and Barrera in a Home Depot parking lot. There are
no accompanying facts in the affidavit to support the
inferences that the crates contained ecstasy or that
Underwood knew or should have known the crates contained
ecstasy. Kaiser advanced DEA Agent Johnson’s belief that
the crates contained ecstasy, but did not provide underlying
facts that could be used to judge the reasonableness of
Johnson’s belief.

    Moreover, the affidavit provides no factual basis for the
conclusion that drug trafficking evidence would be found at
Underwood’s home. As explained in part A, the expert
opinion about drug traffickers keeping evidence of their
crimes at their homes is foundationless because the affidavit
did not assert that Underwood was a drug trafficker, and thus
cannot be used to support probable cause. Further, even if we
make the unreasonable inferences that the crates contained
drugs and that Underwood knew the crates contained drugs,
Underwood delivered those crates to Luong and Barrera, who
took them away from him. We thus cannot conclude that any
drugs contained in those crates were in Underwood’s
possession, let alone at Underwood’s house in particular. The
affidavit does not assert that any other deliveries by
Underwood to anyone else ever took place. Thus, it would
also be unreasonable to conclude that Underwood ever
possessed any other crates, let alone that such crates would be
at Underwood’s house.
20              UNITED STATES V. UNDERWOOD

    Ultimately, the affidavit reasonably supports only the
following innocent conclusions: Underwood knows Luong
and Barrera; he helped Luong and Barrera move two crates
on one occasion2; and Underwood possibly uses marijuana.
Reasonable judges would agree that probable cause did not
exist to search Underwood’s Mansa Drive house because the
affidavit provides only the most attenuated support for the
conclusion that Underwood is a drug courier and no support
for the conclusion that drug trafficking evidence would be
found at Mansa Drive. Thus, the affidavit was a bare bones
affidavit, and the good faith exception to the exclusionary
rule is per se not met.

    The government cites Messerschmidt for the proposition
that extrinsic evidence should be considered in determining
whether the affidavit was a bare bones affidavit. In
Messerschmidt, the Supreme Court found that the good faith
exception to the exclusionary rule applied, and thus any
potential overbreadth as to the scope of the search would not
result in the exclusion of any evidence seized as a result of
the search. 132 S. Ct. at 1250. In determining that the
officer’s reliance was reasonable, the Court gave weight to
the fact that the officer sought and obtained approval of the
warrant application from both a superior officer and a deputy
district attorney. Id. at 1249. In so doing, the Court
demonstrated that evidence extrinsic to the affidavit can be
considered in a good faith determination. But Messerschmidt
did not change the law regarding Leon’s four per se situations
that fail to satisfy good faith, including the situation that
applies here.



  2
    The circumstances are certainly suspicious, but not clear enough to
warrant a conclusion.
              UNITED STATES V. UNDERWOOD                     21

    The language of Leon makes clear that we need not
consider extrinsic factors in making the bare bones affidavit
determination. Before describing the four situations that per
se fail to establish good faith, the Leon Court stated, “it is
clear that in some circumstances the officer will have no
reasonable grounds for believing that the warrant was
properly issued.” 469 U.S. at 922–23. Thus, in these four
circumstances, including the circumstance of a bare bones
affidavit, the officer can never have a reasonable ground for
believing the warrant had probable cause.

     Moreover, in explaining the bare bones affidavit situation
in particular, the Court in Leon stated, “[n]or would an officer
manifest objective good faith in relying on a warrant based on
an affidavit so lacking in indicia of probable cause as to
render official belief in its existence entirely unreasonable.”
468 U.S. at 923 (1984) (emphasis added) (internal quotation
marks omitted). This language makes clear that when the
affidavit itself lacks indicia of probable cause, simply looking
at the affidavit would be sufficient to alert any reasonable
officer that probable cause does not exist. Accordingly, when
we have determined that the affidavit is a bare bones
affidavit, as we have here, even if the extrinsic factors point
to reasonableness, they would not change the result. Reliance
upon a bare bones affidavit is never reasonable.

     Thus, once we determine that the affidavit is a bare bones
affidavit, we can conclude the good faith exception is not
met, and end the inquiry without looking to extrinsic factors.
See Luong, 470 F.3d at 905 (“Given that the facts of this case
fall squarely within the situation explicitly identified in Leon
as one in which the good faith exception does not apply, we
need not inquire further.”).
22            UNITED STATES V. UNDERWOOD

    We briefly note, however, that even assuming arguendo
the affidavit was not a bare bones affidavit, the good faith
exception is not met in this case.

     First, at the time the affidavit was prepared, the law was
clear that an affidavit must have sufficient factual information
and that the issuing magistrate is not permitted to consider
evidence extrinsic to the affidavit in his or her determination
of probable cause. See, e.g., Ventresca, 380 U.S. at 108–09;
United States v. Anderson, 453 F.2d 174, 175 (9th Cir. 1971).
In light of this established law, Kaiser’s claim that he thought
the probable cause of the unattached federal affidavit carried
over to his state affidavit was unreasonable. The claim is
especially unreasonable in a case such as this where the
previously issued warrant was based on an entirely different,
and much more thorough, affidavit.

    Second, even if Kaiser was under time pressure to
complete the affidavit, this pressure would not weigh in favor
of reasonableness in this case. As we explained in Weber,
time pressure is invalidated as a factor when the government
controlled the search’s timing because “[u]nder these
circumstances, there [is] no need for the hurried judgment
upon which law enforcement decisions must often be based.”
923 F.2d at 1346 (internal quotation marks omitted). Like in
Weber, the search in this case need not have been conducted
imminently. Officers had taken Underwood into custody and
had done a protective sweep of the Mansa Drive house before
they applied for the search warrant for Mansa Drive. Thus,
any time pressure Kaiser experienced is irrelevant to a good
faith determination.

   Finally, unlike the situation in Messerschmidt, Kaiser did
not have a supervisor or anyone else review, let alone
              UNITED STATES V. UNDERWOOD                     23

approve, his affidavit. Messerschmidt established that
whether “the officer[] sought [or] obtained approval of the
warrant application from a superior [or] . . . district attorney
before submitting it to the magistrate provides further support
that an officer could have reasonably believed [the warrant
had probable cause].” 132 S. Ct. at 1249. Kaiser’s cutting
and pasting of the portions of the affidavit sent by Johnson,
without attribution, is not the same thing as the review and
approval by a superior or even peer officer. Such a shortcut
provides no basis for any reasonable belief that the warrant
for the Mansa Drive residence was supported by probable
cause.

    An analysis of the totality of the circumstances, including
extrinsic factors, establishes that reliance on the search
warrant for Mansa Drive was objectively unreasonable.
Thus, even assuming the affidavit was not entirely lacking in
indicia of probable cause, the good faith exception is not met
in this case.

                    IV. CONCLUSION

   For the foregoing reasons, we conclude that the evidence
against Underwood was obtained without a warrant based on
probable cause, and the good faith exception to the
exclusionary rule is not met. Accordingly, the district court’s
order granting the motion to suppress evidence is
AFFIRMED.
