                FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


UNITED STATES OF AMERICA,               No. 13-30077
                Plaintiff-Appellee,
                                           D.C. No.
                v.                      2:12-cr-00119-
                                            MJP-1
MICHAEL ALLAN DREYER,
            Defendant-Appellant.          OPINION


    Appeal from the United States District Court
       for the Western District of Washington
  Marsha J. Pechman, Chief District Judge, Presiding

            Argued and Submitted En Banc
       June 17, 2015— San Francisco, California

               Filed November 4, 2015

  Before: Sidney R. Thomas, Chief Judge, and Stephen
   Reinhardt, Barry G. Silverman, Marsha S. Berzon,
  Consuelo M. Callahan, Milan D. Smith, Jr., Mary H.
  Murguia, Morgan Christen, Paul J. Watford, John B.
   Owens and Michelle T. Friedland, Circuit Judges.

             Opinion by Judge Christen;
            Concurrence by Judge Berzon;
           Concurrence by Judge Reinhardt;
            Concurrence by Judge Owens;
           Concurrence by Judge Silverman
2                  UNITED STATES V. DREYER

                           SUMMARY*


                          Criminal Law

    On issues arising from the Posse Comitatus Act (PCA),
the en banc court affirmed the district court’s denial of a
suppression motion, and remanded to the three-judge panel
for consideration of remaining issues, in a case in which the
defendant was convicted of one count of distributing child
pornography and one count of possessing child pornography.

    A special agent of the Naval Criminal Investigative
Service (NCIS) conducted an investigation into computers in
Washington state sharing child pornography by utilizing a
software query that encompassed the entire state but did not
isolate or look for military service members.           The
investigation revealed that the defendant, a civilian, had
shared child pornography files, and the NCIS passed that
information along to the local police department.

    The en banc court reaffirmed the holding in United States
v. Chon, 210 F.3d 990 (9th Cir. 2000), that the NCIS and its
civilian agents are subject to PCA-like restrictions
proscribing direct assistance to civilian law enforcement.

    The en banc court held that the NCIS agent’s
investigation violated PCA-like restrictions, where the agent
set up the software to cast a net across the entire state of
Washington, knowing the sweep would include countless
devices that had no ties to the military and thus did not fall

  *
    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. DREYER                        3

within the jurisdiction of the Uniform Code of Military
Justice. The en banc court could not conclude that the
investigation had a legitimate independent military purpose
because the methodology employed so clearly violated
Department of Defense and naval policy, as well as the
boundary Congress imposed through the PCA and 10 U.S.C.
§ 375. The en banc court observed that the agent’s testimony
illustrates that the violations likely resulted from institutional
confusion about the scope and contours of the PCA and PCA-
like restrictions.

    The en banc court exercised its discretion to reach the
issue of suppression, and concluded that on this record and at
this juncture, the facts of the case do not demonstrate a need
to deter future violations by suppressing the results of the
investigation.

   Concurring, Judge Berzon, joined by Judge Reinhardt,
wrote separately to explain why she is comfortable with the
holding that suppression is not warranted, although the panel
opinion she authored held otherwise.

    Concurring, Judge Reinhardt wrote that he is in complete
agreement with both Judge Christen’s and Judge Berzon’s
views.

    Concurring in the judgment, Judge Owens, joined by
Judges Silverman and Callahan, wrote that he believes that
absent express congressional authorization, suppression is not
a remedy for PCA violations.

   Concurring in the judgment, Judge Silverman, joined by
Judge Callahan, wrote that the agent did not violate the PCA-
4               UNITED STATES V. DREYER

like regulations, both because his assistance of civilian law
enforcement was indirect and because his limited
involvement had an independent military purpose.


                        COUNSEL

Erik B. Levin (argued), Law Office of Erik B. Levin,
Berkeley, California, for Defendant-Appellant.

Helen J. Brunner (argued), Marci Ellsworth, Assistant United
States Attorneys; Scott A.C. Meisler, Criminal Division,
Appellate Section, U.S. Department of Justice; Jenny A.
Durkan, United States Attorney, and Annette L. Hayes,
Acting United States Attorney, Western District of
Washington, Seattle, Washington, for Plaintiff-Appellee.

Hanni Fakhoury and Jennifer Lynch, Electronic Frontier
Foundation, San Francisco, California; Nancy L. Talner, T.
Jared Friend, American Civil Liberties Union of Washington,
Seattle, Washington; Venkat Balasubramani, Focal PLLC,
Seattle, Washington; and David M. Porter, Co-Chair,
National Association of Criminal Defense Lawyers Amici
Curiae Committee, for amici curiae.
                    UNITED STATES V. DREYER                                5

                               OPINION

CHRISTEN, Circuit Judge:

    This case requires us to decide whether a Naval Criminal
Investigative Service agent’s involvement in civilian law
enforcement constitutes a violation of the Posse Comitatus
Act, and if so, whether that violation warrants excluding
evidence obtained as a result of the involvement. We have no
trouble concluding that the facts giving rise to the criminal
charges in this case present clear violations of a congressional
directive prohibiting the use of the military in civilian law
enforcement. We decline to compel suppression because the
facts of this case do not demonstrate that suppression is
needed to deter future violations. We affirm the district
court’s denial of Dreyer’s motion to suppress.1

                          BACKGROUND

    Steve Logan is a special agent of the Naval Criminal
Investigative Service (“NCIS”), “the investigative unit of the
Navy.” See United States v. Chon, 210 F.3d 990, 992 (9th
Cir. 2000). He is a civilian employee stationed in Brunswick,
Georgia. In 2010, Logan and two other NCIS agents initiated
a criminal investigation of the distribution of child
pornography on the Internet. They used RoundUp, a software

  1
     In this opinion, we reach only the issues pertaining to the Posse
Comitatus Act and the exclusionary rule. We remand the case to the
original three-judge panel for consideration of the remaining issues. See
Kyocera Corp. v. Prudential-Bache Trade Servs., Inc., 341 F.3d 987, 995
(9th Cir. 2003) (en banc) (“If the Court votes to hear or rehear a case en
banc, the en banc court may, in its discretion, choose to limit the issues it
considers.” (alteration omitted) (quoting Summerlin v. Stewart, 309 F.3d
1193, 1193 (9th Cir. 2002))).
6                UNITED STATES V. DREYER

investigative tool that monitors online distribution of known
child pornography files around the world.

    RoundUp was developed for the Internet Crimes Against
Children Task Force. The task force comprises federal, state,
and local law enforcement officers investigating internet
crimes against children, including distribution of child
pornography. RoundUp software is not commercially
available because it was designed to be used almost
exclusively by task force members. It uses a database of
known child pornography files compiled by the National
Center for Missing and Exploited Children. To ascertain the
presence of such files, RoundUp relies on unique file
identifiers called SHA-1 hash values, which are essentially
“digital fingerprint[s]” associated with electronic media.
SHA-1 hash values remain unchanged as long as the file itself
is not altered. RoundUp searches for these identifiers on
peer-to-peer file-sharing networks, where individuals upload
documents and media to share with others. Uploaded images
are publicly available to all users of the file-sharing network.

    In 2011, NCIS agents in Washington state asked Logan to
investigate computers in Washington sharing child
pornography. Logan agreed and used RoundUp to search
Gnutella, a peer-to-peer file-sharing network. The RoundUp
query encompassed the entire state of Washington. Logan
later testified that RoundUp cannot “isolate and look for
military service members” because it has only geographic
parameters. The software detected a computer at Internet
Protocol (“IP”) address 67.160.77.21 that had shared several
files identified as child pornography. Logan downloaded two
images and a video from the IP address and verified that they
depicted child pornography.
                    UNITED STATES V. DREYER                               7

    Logan contacted NCIS’s representative at the National
Center for Missing and Exploited Children and requested an
administrative subpoena for the name and physical address
associated with the IP address. The form required a “Reason
for Subpoena,” where Logan wrote: “Suspect IP was
identified in area of large [Department of Defense] and [U.S.
Navy] saturation indicating likelihood of USN/DOD
suspect.” The Center forwarded the request to the FBI, and
the FBI sent an administrative subpoena to Comcast.
Comcast identified Michael Dreyer of Algona, Washington,
as the person associated with the subject IP address.

    When Logan learned through a background check that
Dreyer had no present military affiliation, he prepared a
report of his investigation and sent all relevant materials to an
NCIS agent in Washington.2 That agent passed the
information along to the Algona Police Department in May
2011, and the police department obtained a search warrant
from a state court.

    On July 6, 2011, local police officers executed the
warrant on Dreyer’s residence, where an examination of
Dreyer’s computer revealed several images and videos of
child pornography. The officers arrested Dreyer and seized
his computer and several other digital devices. Dreyer was
charged with six counts of possessing depictions of minors
engaged in sexually explicit conduct in violation of Revised
Code of Washington 9.68A.070.



 2
     Although one of the concurrences states that Logan promptly ended
military involvement when he discovered that Dreyer was a civilian, the
record is clear that he turned his investigative results over to NCIS agents
in Washington, not civilian authorities.
8                UNITED STATES V. DREYER

    In December 2011, a special agent of the United States
Department of Homeland Security obtained a federal warrant
to search Dreyer’s computer and other devices. A subsequent
search of the computer yielded 21 videos and over 1,300
images of child pornography. Dreyer was charged with one
count of distributing child pornography in violation of 18
U.S.C. § 2252(a) and (b)(1), and one count of possessing
child pornography in violation of 18 U.S.C. § 2252(a)(4)(B)
and (b)(2).

    In the federal case, Dreyer moved to suppress the
evidence seized pursuant to both the state and federal
warrants. Among other claims, Dreyer argued that Logan’s
search violated the Posse Comitatus Act, which generally
prohibits use of the military to conduct civilian law
enforcement activities. See 18 U.S.C. § 1385. The district
court ruled it was not “unusual or inappropriate for NCIS to
make a referral to [its] counterparts” and denied Dreyer’s
motion.

    Dreyer was convicted of both federal charges after a four-
day jury trial. He was sentenced to 216 months’ incarceration
and lifetime supervised release. After Dreyer timely
appealed, a divided three-judge panel of this court reversed
and remanded. United States v. Dreyer, 767 F.3d 826, 837
(9th Cir. 2014).

    The panel held that Logan’s actions violated restrictions
imposed pursuant to the Posse Comitatus Act (“PCA”), id. at
829–35, 838–39, and that the district court erred by failing to
suppress the evidence seized as a result of NCIS’s
investigation, id. at 837. The dissent argued that the
exclusionary rule is an extraordinary remedy that is
                 UNITED STATES V. DREYER                     9

unwarranted in this case. Id. at 838–42 (O’Scannlain, J.,
dissenting).

    A majority of the active judges of our court voted to
rehear this case en banc to reconsider the important issues it
presents. United States v. Dreyer, 782 F.3d 416, 417 (9th Cir.
2015). We have jurisdiction pursuant to 28 U.S.C. § 1291.

                STANDARD OF REVIEW

    “A district court’s grant or denial of a motion to suppress
is reviewed de novo.” United States v. Maddox, 614 F.3d
1046, 1048 (9th Cir. 2010). We also review de novo the
question whether the PCA was violated because it is a mixed
question of fact and law that is primarily legal. United States
v. Hitchcock, 286 F.3d 1064, 1069 (9th Cir.), as amended by
298 F.3d 1021 (9th Cir. 2002).

                       DISCUSSION

I. PCA-like restrictions apply to NCIS and its civilian
   agents.

    “Posse comitatus (literally ‘power of the country’) was
defined at common law as all those over the age of 15 upon
whom a sheriff could call for assistance in preventing any
type of civil disorder.” See H.R. Rep. No. 97-71, pt. 2, at 4
(1981) (citing 1 William Blackstone, Commentaries 343–44).
In 1878, Congress codified a prohibition on the use of the
military in civilian law enforcement activities by enacting the
PCA. See Act of June 18, 1878, ch. 263, 20 Stat. 152 (1878)
(current version at 18 U.S.C. § 1385). The current version of
the Act provides:
10               UNITED STATES V. DREYER

        Whoever, except in cases and under
        circumstances expressly authorized by the
        Constitution or Act of Congress, willfully
        uses any part of the Army or the Air Force as
        a posse comitatus or otherwise to execute the
        laws shall be fined under this title or
        imprisoned not more than two years, or both.

18 U.S.C. § 1385. The statute “eliminate[s] the direct active
use of Federal troops by civil law authorities,” United States
v. Banks, 539 F.2d 14, 16 (9th Cir. 1976), and “prohibits
Army and Air Force military personnel from participating in
civilian law enforcement activities,” Chon, 210 F.3d at 993.
Writing on behalf of the Supreme Court, Chief Justice Burger
considered Army surveillance of civilian affairs and
described “a traditional and strong resistance of Americans to
any military intrusion into civilian affairs” that “has deep
roots in our history and found early expression, for example,
in the Third Amendment’s explicit prohibition against
quartering soldiers in private homes without consent and in
the constitutional provisions for civilian control of the
military.” Laird v. Tatum, 408 U.S. 1, 15 (1972). As in
Laird, “[t]hose prohibitions are not directly presented by this
case, but their philosophical underpinnings explain our
traditional insistence on limitations on military operations in
peacetime” and our historical concern that “unlawful
activities of the military [c]ould go unnoticed or
unremedied.” Id. at 15–16.

     In 1981, Congress enacted a separate statute directing:

        The Secretary of Defense shall prescribe such
        regulations as may be necessary to ensure that
        any activity (including the provision of any
                    UNITED STATES V. DREYER                             11

         equipment or facility or the assignment or
         detail of any personnel) . . . does not include
         or permit direct participation by a member of
         the Army, Navy, Air Force, or Marine Corps
         in a search, seizure, arrest, or other similar
         activity unless participation in such activity
         by such member is otherwise authorized by
         law.

10 U.S.C. § 375.3 In consideration of this provision, we have
held that “[a]lthough the PCA does not directly reference the
Navy or Marine Corps,” Congress prohibits “Navy
involvement in enforcing civilian laws.” Chon, 210 F.3d at
993. Pursuant to § 375, the Secretary of Defense issued
regulations in 1982 that provided, in part:

         [T]he prohibition on use of military personnel
         “as a posse comitatus or otherwise to execute
         the laws” prohibits the following forms of
         direct assistance:

              (i) Interdiction of a vehicle, vessel,
              aircraft or other similar activity.

              (ii) A search or seizure.

              (iii) An arrest, stop and frisk, or similar
              activity.

              (iv) Use of military personnel for
              surveillance or pursuit of individuals, or

  3
    There are certain exceptions to § 375, but they are not at issue in this
case. See 10 U.S.C. §§ 372–374, 379–382.
12              UNITED STATES V. DREYER

           as informants, undercover          agents,
           investigators, or interrogators.

32 C.F.R. § 213.10(a)(3) (1982). In 1986, the Department of
Defense (“DoD”) issued a policy containing substantially
identical content and stating that “guidance on the Posse
Comitatus Act . . . is applicable to the Department of the
Navy and the Marine Corps as a matter of DoD policy.” DoD
Directive (“DoDD”) 5525.5 § E4.3 (Jan. 15, 1986). “[T]he
Secretary of the Navy, using nearly identical language, has
adopted this policy.” Chon, 210 F.3d at 993 (citing former
Secretary of the Navy Instructions (SECNAVINST) 5820.7B
(Mar. 28, 1998)); see also SECNAVINST 5820.7C (Jan. 26,
2006) (current policy containing similar content).

    In 1993, the Secretary of Defense removed 32 C.F.R. part
213, stating that the regulations had “served the purpose for
which they were intended and are no longer valid.” Removal
of Parts, 58 Fed. Reg. 25,776-01 (Apr. 28, 1993). Though the
congressional directive in 10 U.S.C. § 375 is unambiguous,
no regulations were in place for some 20 years. In April
2013, regulations under § 375 were reissued with content
substantively similar to the regulations that had previously
been in place. See 32 C.F.R. § 182.6 (2013). Compare 32
C.F.R. § 213.10(a)(3) (1982) (“Restrictions on direct
assistance.”), with 32 C.F.R. § 182.6(a)(1)(iii) (2013)
(“Restrictions on Direct Assistance.”).

    In United States v. Chon, our court considered a PCA
challenge to NCIS’s involvement in the investigation of theft
of military property. 210 F.3d at 991–93. We held that the
“PCA-like restrictions” adopted pursuant to § 375 apply to
the Navy and NCIS, but we concluded that the investigation
in Chon was permissible because “it was undertaken for the
                   UNITED STATES V. DREYER                           13

independent military purpose of recovering military
equipment.” Id. at 993–94. As here, the investigation in
Chon took place when there was no enabling regulation
specifically prohibiting direct participation by a member of
the Navy in civilian law enforcement. Id. at 992–93.
Nevertheless, § 375 and the DoD and naval policies were
intact at all relevant times, and Chon relied on these
provisions when it held that PCA-like restrictions apply to
NCIS and its civilian agents. Id. at 993–94. We reached the
same conclusion in United States v. Hitchcock, where we held
that the Navy and NCIS are bound by the PCA-like
restrictions mandated by § 375. 286 F.3d at 1069–70.4

    The Government argues that PCA-like restrictions do not
apply to NCIS or its agents because NCIS is a civilian law
enforcement agency with no direct reporting relationship to
a military officer. Chon rejected these arguments, holding
that “NCIS is bound by the limitations of § 375.” 210 F.3d at
994. Chon explained that DoD and naval policies:

         exempt four categories of people from PCA-
         like restrictions: (1) members of reserve
         components when not on active duty; (2)
         members of the National Guard when not in
         the Federal Service; (3) civilian employees of
         DoD unless under the direct command and
         control of a military officer; and (4) military


 4
     Hitchcock explained that 32 C.F.R. § 213.10 (1982) was merely “a
prior version of DoD Directive 5525.5,” and observed that PCA-like
restrictions “remain controlling” despite the absence of regulations.
Hitchcock, 286 F.3d at 1069–70 & n.8; see also United States v. Khan, 35
F.3d 426, 431 (9th Cir. 1994) (“[T]he Posse Comitatus Act applies to the
Navy through [10 U.S.C. §] 375 and 32 C.F.R. § 213.10 [(1982)].”).
14              UNITED STATES V. DREYER

       service members when off duty and in a
       private capacity.

Id. at 993. We interpreted “these exemptions to mean that the
PCA and PCA-like restrictions function to proscribe use of
the strength and authority of the military rather than use of
the private force of the individuals who make up the
institution.” Id. We specifically held that PCA-like
restrictions do apply to “civilian NCIS agents [who]
represent[] and further[] the interests of the Navy,” and whom
civilians are unable to distinguish from military agents. Id.
We reached this result relying on § 375 and DoD and naval
policy. Id. at 993–94. We see no need to depart from Chon’s
analysis in Dreyer’s case.          See 10 U.S.C. § 375;
SECNAVINST 5820.7C(8)(e)(1)–(4); DoDD 5525.5 § E4.2.

    The Government correctly points out that the reporting
relationship between NCIS and the Navy has changed since
Chon was decided, but that change does not affect the
outcome of Dreyer’s case because NCIS continues to
“report[] directly” to the Navy. See SECNAVINST
5430.107(5)(a) (Dec. 28, 2005). The Navy’s current policies
also require that a Board of Directors oversee NCIS strategy
and operations and facilitate the Navy’s “corporate
governance” of NCIS. See SECNAVINST 5430.107(5)(c).
The Board includes military officers such as the Vice Chief
of Naval Operations and the Assistant Commandant of the
Marine Corps. Id. This structure leaves no doubt about the
existence of a reporting relationship between NCIS and
military officers. In short, nothing in the current policies
undermines Chon’s rejection of the same argument the
Government asserts here.
                  UNITED STATES V. DREYER                       15

    New DoD regulations comport with the conclusion that
PCA-like restrictions apply to NCIS. Although these
regulations were issued after NCIS conducted the subject
investigation, they are notable because they are an agency
interpretation of a statutory provision that has remained
unchanged. Cf. Pipefitters Local Union No. 562 v. United
States, 407 U.S. 385, 411–12 (1972) (considering later
legislation in interpretation of earlier enactment). The
regulations define “DoD personnel” as “Federal military
officers and enlisted personnel and civilian employees of the
Department of Defense.” 32 C.F.R. § 182.3 (emphasis
added). They state that “DoD personnel are prohibited from
providing [specified] forms of direct civilian law enforcement
assistance,” including “search or seizure”; “[e]vidence
collection”; “[s]urveillance . . . of individuals [or] items, . . .
or acting as undercover agents, informants, [or]
investigators”; and “[f]orensic investigations or other testing
of evidence obtained from a suspect for use in a civilian law
enforcement investigation in the United States unless there is
a DoD nexus.” 32 C.F.R. § 182.6(a)(1)(iii)(A). The new
regulations expressly “[a]ppl[y] to civilian employees of the
DoD Components,” and “to all actions of DoD personnel
worldwide.” 32 C.F.R. §§ 182.2(e), 182.4(c). The Secretary
of Defense instituted these regulations under express
congressional delegation, see 10 U.S.C. § 375, and they
unambiguously interpret PCA-like restrictions to apply to
civilian employees of DoD.

    We reaffirm Chon’s holding that NCIS and its civilian
agents are subject to PCA-like restrictions proscribing direct
assistance to civilian law enforcement. See Chon, 210 F.3d
at 994. Congress did not make voluntary its requirement that
the Secretary of Defense establish regulations prohibiting
military involvement in civilian law enforcement, and NCIS
16               UNITED STATES V. DREYER

was subject to these restrictions when it undertook its
investigation of Dreyer.

II. The violations in this case were systemic, but likely the
    result of institutional confusion that existed at the
    time.

     A. Logan’s investigation           violated    PCA-like
        restrictions.

    PCA-like restrictions prohibit direct military involvement
in civilian law enforcement activities, but they permit some
indirect assistance, such as involvement that arises “during
the normal course of military operations or other actions that
‘do not subject civilians to the use of military power that is
regulatory, prescriptive, or compulsory.’” Hitchcock, 286
F.3d at 1069 (alterations omitted) (quoting DoDD 5525.5
§ E4.1.7.2). Permissible indirect assistance “must not
‘constitute the exercise of regulatory, proscriptive, or
compulsory military power,’ must not ‘amount to direct
active involvement in the execution of the laws,’ and must
not ‘pervade the activities of civilian authorities.’” United
States v. Khan, 35 F.3d 426, 431 (9th Cir. 1994) (quoting
United States v. Yunis, 924 F.2d 1086, 1094 (D.C. Cir.
1991)). “If any one of these tests is met, the assistance is not
indirect.” Id.

    The Government argues that NCIS’s involvement in the
Washington investigation constituted permissible indirect
assistance because NCIS merely transferred information to
civilian law enforcement. Not so. In contrast to cases where
military personnel offered only subsidiary support, Logan’s
investigation in this case pervaded the actions of civilian law
enforcement. Cf. United States v. Klimavicius-Viloria, 144
                 UNITED STATES V. DREYER                     17

F.3d 1249, 1259 (9th Cir. 1998) (no violation where the Navy
merely supplied equipment, logistical support, and backup
security); Khan, 35 F.3d at 431–32 (same). Logan testified
that he and two other NCIS agents initiated an operation to
search for individuals sharing child pornography online. His
report on the Washington investigation formed the basis of
the state warrant to search Dreyer’s home, and execution of
that warrant yielded the evidence that led to the charges
against Dreyer. Logan testified that he was not engaged in
“surveillance,” which he described as “watching.” He
explained that he was instead conducting an “investigation,”
an activity he described as “active.” This conduct is
expressly prohibited as direct assistance. See DoDD 5525.5
§ E4.1.3.4 (identifying under “[r]estrictions on [d]irect
[a]ssistance” the “[u]se of military personnel for surveillance
or pursuit of individuals, or as undercover agents, informants,
investigators, or interrogators”); see also United States v. Red
Feather, 392 F. Supp. 916, 925 (D.S.D. 1975) (“Activities
which constitute an active role in direct law enforcement
[include] investigation of a crime . . . .”).

    We have recognized that PCA-like restrictions allow “an
exception to the general prohibition on direct involvement
where the military participation is undertaken ‘for the
primary purpose of furthering a military or foreign affairs
function of the United States, regardless of incidental benefits
to civilian authorities.’” Hitchcock, 286 F.3d at 1069
(quoting DoDD 5525.5 § E4.1.2.1). This exception includes,
for example, “investigations and other actions related to
enforcement of the Uniform Code of Military Justice.” Id. at
1070 (alteration omitted) (quoting DoDD 5525.5
§ E4.1.2.1.1). Courts have regularly construed that code to
prohibit members of the armed forces from possessing child
pornography. See, e.g., United States v. Stoltz, 720 F.3d
18               UNITED STATES V. DREYER

1127, 1130 (9th Cir. 2013); United States v. Brown, 529 F.3d
1260, 1262 (10th Cir. 2008); United States v. Allen, 53 M.J.
402, 407 (C.A.A.F. 2000). Properly executed, investigations
of possession or distribution of child pornography by military
personnel could be excepted from PCA-like restrictions.

    Logan did not undertake such an investigation. Instead,
he used RoundUp to conduct a statewide audit of all
computers engaged in file sharing. Logan represented to the
FBI that he sought an administrative subpoena “in [an] area
of large DOD and USN saturation indicating likelihood of
USN/DOD suspect” (emphasis added), but the computer
query employed in this case was in no way limited to
members of the military. See 10 U.S.C. § 802 (identifying
persons subject to the UCMJ). To the contrary, Logan later
testified that he had been “monitoring any computer IP
address within a specific geographic location . . . not specific
to US military only, or US government computers,” and that
it was his “standard practice[] to monitor all computers in a
geographic area.” Here, Logan set RoundUp to cast a net
across the entire state of Washington, knowing the sweep
would include countless devices that had no ties to the
military and thus did not fall under the jurisdiction of the
Uniform Code of Military Justice. The investigation in this
case was not reasonably tied to military bases, military
facilities, military personnel, or military equipment. Cf.
Hitchcock, 286 F.3d at 1070 (applying exception where NCIS
agent investigated the use and distribution of LSD on a
military base); Chon, 210 F.3d at 994 (applying exception
where NCIS agents investigated theft of military equipment
from a naval facility).

   Logan and the NCIS agents who worked with him
spearheaded a law enforcement investigation that would
                 UNITED STATES V. DREYER                    19

inevitably encompass mostly civilian-owned computers. We
cannot conclude that the investigation had a legitimate
independent military purpose because the methodology NCIS
employed so clearly violated DoD and naval policy, as well
as the boundary Congress imposed through the PCA and
§ 375.

   B. The violations in this case likely resulted from
      institutional error.

     Logan’s testimony illustrates that the violations in this
case likely resulted from institutional confusion about the
scope and contours of the PCA and PCA-like restrictions. On
the incomplete record available, we cannot tell whether
Logan’s practices were as widespread as Dreyer argues they
were, but it is certain that the NCIS activity in this case was
not an isolated incident. Logan and two other NCIS agents
initiated their child pornography investigative operation in
2010. The operation involved at least three agents and had
been underway for 19 months at the time of the trial in this
case. Logan testified in another federal proceeding that “th[e]
operation was cleared all the way through NCIS headquarters
back in 2010.” See Transcript of Supplemental Motion to
Suppress Evidence (Transcript) at 75, United States v.
Gentles, No. 1:12-cr-120 (E.D. Mo. Oct. 16, 2014), ECF No.
112; see also Rosales-Martinez v. Palmer, 753 F.3d 890, 894
(9th Cir. 2014) (“It is well established that we may take
judicial notice of judicial proceedings in other courts.”).

    Logan also testified that his duties as an NCIS agent were
“[t]o investigate any federal, U.S. federal crimes, or crimes
against the Uniform Code of Military Justice.” He also
claimed he had authority to investigate “[p]ossession and
distribution of child pornography across the [I]nternet”
20                UNITED STATES V. DREYER

because it is “a federal crime” and NCIS agents “are
credentialed U.S. federal agents.” Notably, at one point
Logan specifically disavowed that his investigative authority
was limited:

        Q. . . . [Y]ou are limited in the areas that you
        can investigate, wouldn’t that be correct?

        A. No, sir, that would not be correct.

Contrary to the suggestion in one of the concurrences, Logan
at no point testified that he limited his investigations to
military personnel, and the foregoing testimony indicates that
he did not believe his authority to be limited to military
personnel.

    Indeed, Logan explained that he had a standard practice
of “monitor[ing] all computers in a [certain] geographic area”
without regard to military status. Yet RoundUp’s geographic
accuracy is limited to “a 25- to 30-mile radius.” We
recognize that because some military bases are in remote
areas, it might be possible to fashion a targeted RoundUp
inquiry that would encompass only an insignificant number
of civilian-owned computers. The record does not tell us
whether the scope of the other NCIS investigations Logan
described went beyond geographic areas that legitimately
could be expected to include high concentrations of military
personnel. What is clear is that the investigation in Dreyer’s
case resulted from an investigative technique that NCIS did
not consider to be out of bounds. To the contrary, Logan
testified that after the three-judge panel of this court issued its
opinion unanimously finding that his conduct violated PCA-
like restrictions, NCIS put “[a]bsolutely no[]” restrictions on
him. See Transcript at 75, Gentles, No. 1:12-cr-120 (E.D.
                  UNITED STATES V. DREYER                      21

Mo. Oct. 16, 2014), ECF No. 112. NCIS’s misunderstanding
about the contours of the PCA and PCA-like restrictions is
further evident in the Government’s emphatic assertion
before the district court and the three-judge panel that
Logan’s actions were permissible.

    At best, the record demonstrates a poor understanding of
the restrictions imposed on NCIS’s involvement in civilian
law enforcement. Authorization of the program described in
Logan’s testimony was apparently based on an entirely
incorrect understanding of the PCA-like restrictions that
apply to NCIS.

III.      Although this case presents troubling violations,
          we do not order suppression.

       A. We exercise our discretion to reach the issue of
          suppression.

    The Government argues in its supplemental brief that
suppression is never warranted for PCA violations that do not
implicate constitutional violations. Dreyer strenuously
counters that the Government waived this argument by failing
to raise it before filing its petition for panel rehearing. Dreyer
is correct that the Government did not raise this argument in
the district court, or even when the case was originally
briefed and argued on appeal. The three-judge panel that
originally heard this case unanimously held that PCA-like
restrictions apply to NCIS and that the conduct in this case
violated those restrictions. Dreyer, 767 F.3d at 829–35,
838–39. One member of the panel concluded exclusion was
not warranted. Id. at 838–42 (O’Scannlain, J., dissenting).
22                 UNITED STATES V. DREYER

    Generally, an appellee waives any argument it fails to
raise in its answering brief. See Clem v. Lomeli, 566 F.3d
1177, 1182 (9th Cir. 2009). But “the rule of waiver is a
discretionary one,” Ruiz v. Affinity Logistics Corp., 667 F.3d
1318, 1322 (9th Cir. 2012) (quoting Ackerman v. W. Elec.
Co., 860 F.2d 1514, 1517 (9th Cir. 1988)), and we can “make
an exception to waiver . . . in the exceptional case in which
review is necessary to prevent a miscarriage of justice or to
preserve the integrity of the judicial process,” id. (quoting
Bolker v. C.I.R., 760 F.2d 1039, 1042 (9th Cir. 1985)). Here,
we exercise our discretion to consider whether suppression is
warranted because, under the unique facts of this case, doing
so best serves the integrity of the judicial process.5 Our
decision to do so is informed in part by our conclusion that
the important issues in this case will reoccur until they are
addressed by the court.

     B. The facts of this case do not demonstrate that
        suppression is needed to deter future violations.

    “Suppression of evidence . . . has always been our last
resort, not our first impulse.” Hudson v. Michigan, 547 U.S.
586, 591 (2006). Courts do not invoke the exclusionary rule
absent compelling circumstances:

        The exclusionary rule generates substantial
        social costs, which sometimes include setting
        the guilty free and the dangerous at large. We
        have therefore been cautious against


 5
     Dreyer had the opportunity to present his arguments on the
suppression issue in supplemental briefing. See Alcaraz v. I.N.S., 384
F.3d 1150, 1161 (9th Cir. 2004) (no prejudice where party presents
relevant arguments in supplemental briefing).
                   UNITED STATES V. DREYER                            23

         expanding it, and have repeatedly emphasized
         that the rule’s costly toll upon truth-seeking
         and law enforcement objectives presents a
         high obstacle for those urging its application.

Id. (alterations and citations omitted); see also Sanchez-
Llamas v. Oregon, 548 U.S. 331, 347 (2006) (“[T]he
exclusionary rule is not a remedy we apply lightly.”). One of
the concurrences cites Davis v. United States, 131 S. Ct.
2419, 2427 (2011), in support of its suggestion that the
Supreme Court has, in recent years, made more stringent the
test for invoking the exclusionary rule. But Davis is entirely
consistent with Hudson and Sanchez-Llamas, and we
recognize that all three cases reflect the Supreme Court’s
recent direction that the rule is a remedy of last resort that is
warranted only when “the deterrence benefits . . . outweigh
[the] heavy costs.” Id. at 2427.

    In its recent decisions, the Supreme Court has not held
that suppression is never available for certain violations;
rather, it explained that the exclusionary rule is applied
“primarily to deter constitutional violations” and violations
of statutes that enforce constitutional norms. Sanchez-
Llamas, 548 U.S. at 348 (emphasis added); see also United
States v. Harrington, 681 F.2d 612, 615 (9th Cir. 1982)
(“There must be an exceptional reason, typically the
protection of a constitutional right, to invoke the exclusionary
rule.”). Notably, Dreyer does not argue that NCIS violated
his Fourth Amendment rights.6


 6
     Dreyer voluntarily placed pornographic images on a peer-to-peer file-
sharing network, granting members of the public free access to them.
Under our Fourth Amendment jurisprudence, accessing files made
available through file-sharing software does not constitute a search.
24                  UNITED STATES V. DREYER

      The exclusionary rule is certainly available for violations
of constitutional rights, but the Supreme Court has approved
of using the rule to remedy statutory violations only in rare
circumstances. See Miller v. United States, 357 U.S. 301,
313–14 (1958) (requiring suppression of evidence uncovered
in search incident to unlawful arrest); McNabb v. United
States, 318 U.S. 332, 344–45 (1943) (invoking suppression
for violation of statutory right intended to ward against “all
the evil implications of secret interrogation,” a concern rooted
in the Fifth Amendment). Apart from the Fourth and Fifth
Amendment concerns regarding unlawful searches and
interrogations, the Supreme Court has not specifically
identified “statutory violations that enforce constitutional
norms,” nor has it described the degree of constitutional
nexus required to invoke suppression for a statutory violation.
See, e.g., Sanchez-Llamas, 548 U.S. at 348 (“The few cases
in which we have suppressed evidence for statutory violations
. . . arose directly out of statutory violations that implicated
important Fourth and Fifth Amendment interests.”). The
PCA does have constitutional underpinnings,7 however, and


United States v. Ganoe, 538 F.3d 1117, 1127 (9th Cir. 2008) (no
objectively reasonable expectation of privacy in files shared through file-
sharing software). We have said that when an individual uses a file-
sharing software, he “open[s] his computer to anyone else with the same
freely available program,” thereby “open[ing] up his download folder to
the world.” Id.
  7
     The Supreme Court has recognized that “concerns [about] Army
surveillance activities . . . reflect a traditional and strong resistance of
Americans to any military intrusion into civilian affairs[,] [which] found
early expression . . . in the Third Amendment[].” Laird, 408 U.S. at 15;
see also United States v. Walden, 490 F.2d 372, 375 (4th Cir. 1974)
(“[T]he [PCA] was no more than an expression of constitutional
limitations on the use of the military to enforce civil laws.”); 7 Cong. Rec.
4247 (1878) (remarks of Sen. Benjamin Hill) (use of military power to
                    UNITED STATES V. DREYER                             25

we know of no controlling precedent precluding application
of the exclusionary rule for a violation of the PCA or § 375
in a case in which exclusion is otherwise warranted. See, e.g.,
United States v. Roberts, 779 F.2d 565, 568 (9th Cir. 1986),
superseded by statute on other grounds as recognized in
Khan, 35 F.3d at 432 n.7.

    Chon squarely held that PCA-like restrictions adopted
pursuant to § 375 apply to NCIS, but we have not addressed
whether the exclusionary rule is the appropriate remedy for
this type of violation since our decision in Roberts. Roberts
concerned a joint effort between the Navy and the Coast
Guard to enforce drug smuggling laws. 779 F.2d at 566.
Coast Guard personnel aboard a Navy frigate noticed a
sailboat, announced their intention to board it, and dispatched
a Coast Guard team on a Navy boarding boat with a Navy
crew. Id. Once aboard the sailboat, the Coast Guard
discovered bales of marijuana. Id. The sailboat crew
members argued that the marijuana should be suppressed
because the Navy’s involvement in the operation violated the
PCA. Id. at 566–67.

    We concluded that the Navy violated 10 U.S.C. § 374,
which “generally requires that [Navy] equipment be used
only ‘for monitoring and communicating the movement of air
and sea traffic,’” id. at 567 (quoting 10 U.S.C. § 374(b)), and
that the Navy violated the “general policy” against “direct
assistance to the Coast Guard” under the PCA, id. at 567–68.
We declined to compel suppression in Roberts because “the
Navy’s violation [of PCA-like restrictions] was unintentional
and in good faith[,] . . . the clear costs of applying an


discharge duties of civil officers supplants “a government for liberty . . .
founded in the consent of the people” with “a government of force”).
26               UNITED STATES V. DREYER

exclusionary rule [we]re not countervailed by any discernible
benefits,” and invoking the rule was inappropriate until there
was a showing of “widespread and repeated violations” and
a need for the remedy. Id. at 568 (quoting United States v.
Wolffs, 594 F.2d 77, 85 (5th Cir. 1979)). Roberts is entirely
consistent with the Supreme Court’s instruction that the
exclusionary rule should be applied “only where its remedial
objectives are thought most efficaciously served—that is,
where its deterrence benefits outweigh its substantial social
costs.” See Hudson, 547 U.S. at 591 (citations omitted). We
affirm our holding in Roberts that “an exclusionary rule
should not be applied to violations of 10 U.S.C. §§ 371–378
until a need to deter future violations is demonstrated.” 779
F.2d at 568.

    RoundUp, file sharing, and related search technology did
not exist when Roberts was decided. Although precedent
from several of our sister circuits mirrors the Roberts rule that
suppression may be appropriate for “widespread and repeated
violations” of PCA-like restrictions, those courts either have
not considered the use of similar search technology in the
context of the PCA, or they have not encountered violations
that are so “widespread and repeated” that they demonstrate
the need for deterrence. See, e.g., United States v. Johnson,
410 F.3d 137, 149 (4th Cir. 2005); Hayes v. Hawes, 921 F.2d
100, 104 (7th Cir. 1990); United States v. Bacon, 851 F.2d
1312, 1313–14 (11th Cir. 1988) (per curiam); Wolffs, 594
F.2d at 85; United States v. Walden, 490 F.2d 372, 377 (4th
Cir. 1974).

    The facts of this case are troubling and unprecedented in
our case law, but they also point to institutional confusion and
show that NCIS misunderstood the scope of its authority.
Logan testified there were no limitations on his authority, but
                 UNITED STATES V. DREYER                       27

he also testified that NCIS agents “are charged with and
mandated to conduct any criminal investigations as it relates
to the Department of the Navy or its assets, its facilities or its
personnel, to include areas in close proximity to the
Department of Navy facilities.” (Emphasis added.)

    Further, contrary to Logan’s testimony that his
investigative operation was approved by “NCIS
headquarters” and that his supervisors took no actions to curb
his activities after a three-judge panel of our court issued its
decision, the Government represented at oral argument that
the military is already in the process of changing its practices
and limiting its participation in civilian law enforcement to
conform to PCA-like restrictions. In its supplemental
briefing and at oral argument, the Government strenuously
argued that “th[is] [c]ourt’s finding of a violation is more
than sufficient to deter NCIS agents from engaging in any
future investigative efforts of this type.” Moreover, after
Logan’s investigation of Dreyer, DoD adopted new
regulations that acknowledge the applicability of PCA-like
restrictions to the Navy and to NCIS. See 32 C.F.R. pt. 182.

    NCIS must conform its investigatory practices to the law,
but we are persuaded that the Government should have the
opportunity to self-correct before we resort to the
exclusionary rule, particularly because it has already
acknowledged the need to do so. Unlike cases in which
courts compel suppression to correct violations committed by
law enforcement agencies, see, e.g., United States v. Sears,
411 F.3d 1124, 1125 (9th Cir. 2005) (affirming suppression
of evidence seized by local law enforcement agents pursuant
to unreviewed portions of search warrant), this case arises
from violations that took place under the purview of the
military, which is unique in its command structure and its
28               UNITED STATES V. DREYER

relationship to the other branches of government. Invoking
the exclusionary rule in this case would do little to redress an
ongoing investigative operation that appears to be the product
of institutional error somewhere in the military’s command
structure, rather than intentional disregard of a statutory
constraint. See Hudson, 547 U.S. at 593 (noting exclusion
may not be justified when “the interest protected by the
constitutional guarantee that has been violated would not be
served by suppression of the evidence obtained”); United
States v. Payner, 447 U.S. 727, 733 n.5 (1980) (“We cannot
assume that similar lawless conduct, if brought to the
attention of responsible officials, would not be dealt with
appropriately.”).

     To be clear, we do not suggest that the exclusionary rule
might be inapplicable for a constitutional violation merely
because government actors who committed the violation do
not understand the legal prohibition. In the more common
Fourth or Fifth Amendment context, institutional confusion
or ignorance is not a ground for refusing to exclude evidence.
See, e.g., United States v. Negrete-Gonzales, 966 F.2d 1277,
1283 (9th Cir. 1992) (“Fundamental errors . . . that result in
clear constitutional violations . . . require suppression, unless
the officers can show objective good faith reliance . . . .”
(citing Fed. R. Crim. P. 41; United States v. Freitas, 856 F.2d
1425, 1433 (9th Cir. 1988); United States v. Luk, 859 F.2d
667, 671 (9th Cir. 1988)). As explained, the scenario
presented by this case is both extreme and unusual.

    The military is best suited to correct this systemic
violation, and it has initiated steps to do so. Therefore, on
this record and at this juncture, we conclude that the facts of
this case do not demonstrate “a need to deter future
violations” by suppressing the results of Logan’s
                 UNITED STATES V. DREYER                     29

investigation. See Roberts, 779 F.2d at 568. We affirm the
district court’s order denying Dreyer’s motion to suppress.

                      CONCLUSION

    On the issues arising from the Posse Comitatus Act, we
affirm the district court’s denial of Dreyer’s motion to
suppress.

   AFFIRMED IN PART, REMANDED IN PART.



BERZON, Circuit Judge, joined by REINHARDT, Circuit
Judge, concurring:

    I join fully in the majority opinion. I write separately to
explain why I am comfortable with the holding that
suppression is not warranted, although the panel opinion I
authored held otherwise. See United States v. Dreyer, 767
F.3d 826, 835–37 (9th Cir. 2014).

    As a preliminary matter, when the case was before our
three-judge panel, the United States never contested that the
exclusionary rule could apply to widespread and repeated
violations of the PCA. The United States did not make this
argument for good reason. Roberts held to the contrary,
stating that the exclusionary rule can be “applied to violations
of 10 U.S.C. §§ 371–78 [if] a need to deter future violations
is demonstrated,” but should not be applied where there is no
such showing. 779 F.2d at 568; see also United States v.
Johnson, 410 F.3d 137, 149 (4th Cir. 2005); Hayes v. Hawes,
921 F.2d 100, 104 (7th Cir. 1990); United States v. Wolffs,
594 F.2d 77, 85 (5th Cir. 1979).
30              UNITED STATES V. DREYER

    Addressing, now, the availability of suppression as a
remedy for violations of the PCA (and PCA-like restrictions),
I emphasize that the PCA is deeply grounded in constitutional
principles. The United States’ interest in checking military
encroachments into civilian affairs finds expression in the
earliest founding documents. See Charles Doyle, Cong.
Research Serv., 95-964 S, The Posse Comitatus Act and
Related Matters: The Use of the Military to Execute Civilian
Law 1–6 (2000). When the colonists set out to win
independence from King George, their resentment of the
Crown’s use of troops to enforce customs laws and
maintenance of standing armies became a rallying cry. See
H.R. Rep. No. 97-71, pt. 2, at 1799 (1981) (statement of Rep.
Conyers); Laird, 408 U.S. at 19 (Douglas, J., dissenting).
The Declaration of Independence denounces the King for
having “kept among us, in times of peace, Standing Armies
without the Consent of our legislatures”; for “affect[ing] to
render the Military independent of and superior to the Civil
power”; and for “[q]uartering large bodies of armed troops
among us.” The Declaration of Independence paras. 11, 12,
14 (U.S. 1776); see 7 Cong. Rec. 3583–86 (1878) (remarks of
Rep. Kimmel).

    These grievances were at the forefront of deliberations at
the Constitutional Convention, as the founders were reluctant
to ratify a constitution that failed to guard against military
dominance. Laird, 408 U.S. at 22–23 (Douglas, J.,
dissenting); Major Clarence I. Meeks III, Illegal Law
Enforcement: Aiding Civil Authorities in Violation of the
Posse Comitatus Act, 70 Mil. L. Rev. 83, 87 (1975). The
Constitution that emerged incorporates their concerns through
the separation of Congress’s power to raise and support the
Army and to provide and maintain a Navy, in Article I,
Section 8, from the President’s power as the Commander-in-
                 UNITED STATES V. DREYER                    31

Chief, in Article II, Section 2. The Domestic Violence
Clause, Article IV, Section Four, provides for military
defense of the states upon invasion and, “on Application of
the Legislature, or of the Executive (when the Legislature
cannot be convened) against domestic Violence”; the military
can restore law in the states in the face of domestic
disruption, but only upon a determination by Congress (or, in
an emergency, the Executive) that military involvement is
necessary. See 7 Cong. Rec. 4240 (remarks of Sen. Kernan).

    The Bill of Rights also incorporates the principle of
separating military force from civilian law. The Second
Amendment provides for a civilian militia; the Third
Amendment prohibits the mandatory quartering of troops;
and the Fourth Amendment prohibits unreasonable
government intrusion in the form of searches and seizures.
See Laird, 408 U.S. at 15–18, 22–23 (Douglas, J. dissenting);
Doyle, supra, at 12; cf. Bissonette v. Haig, 800 F.2d 812,
814–15 (8th Cir. 1986) (en banc), aff’d on other grounds by
485 U.S. 264 (1988), abrogated on other grounds as
recognized in Engleman v. Deputy Murray, 546 F.3d 944, 948
& n.3 (8th Cir. 2008) (holding that plaintiffs who alleged that
they were seized by the Army in violation of the PCA had
stated a Fourth Amendment claim). Indeed, “it is not
unreasonable to believe that our Founders’ determination to
guarantee the preeminence of civil over military power was
an important element that prompted adoption of the
Constitutional Amendments we call the Bill of Rights.”
Laird, 408 U.S. at 23 (Douglas, J., dissenting) (quoting Earl
Warren, The Bill of Rights and the Military, 37 N.Y.U. L.
Rev. 181, 185 (1962)).

  In 1878, when Congress was considering enacting the
PCA, its members repeatedly referred to these constitutional
32               UNITED STATES V. DREYER

concerns. See 7 Cong. Rec. 3583 (remarks of Rep. Kimmel)
(“In every page of the history of the earlier period, long
before, at the time of, and long after the adoption of the
Constitution, the warnings against the dangers of standing
armies are loud, distinct, and constant.”); id. at 4240 (remarks
of Sen. Kernan) (“I suppose no one claims that you can use
the Army as a posse comitatus unless that use is authorized
by the Constitution, which it clearly is not, or by act of
Congress”); id. at 4243 (remarks of Sen. Merrimon) (“The
Army, under the Constitution, is not to be used for the
purpose of executing the law in the ordinary sense of
executing the law. It can only be called into active service for
the purpose of suppressing insurrection . . . .”). As these
comments evince, when Congress enacted the PCA, it
understood that the Act implemented a principle already
embedded in the Constitution. See United States v. Walden,
490 F.2d 372, 375 (4th Cir. 1974).

    Moreover, while it is true that courts generally have in the
past applied the exclusionary rule only to statutory violations
directly implicating the Fourth or Fifth Amendments,
Sanchez-Llamas v. Oregon, 548 U.S. 331, 348–49 (2006);
see, e.g., Miller v. United States, 357 U.S. 301, 313–14
(1958); McNabb v. United States, 318 U.S. 332, 344–45
(1943), as Roberts and other PCA cases reflect, there is no
reason why the rule should not be applied to the violation of
a statute with such a substantial constitutional foundation.
Because of the PCA’s constitutional roots, I continue to agree
that were an “extraordinary” violation shown, suppression
would be warranted. See Roberts, 779 F.2d at 568.

    I also continue to believe the violation here was extreme
in scope, in that, without connection to a military purpose, the
investigation reached all computers in the state of
                UNITED STATES V. DREYER                   33

Washington running the Gnutella file-sharing network, and
similar investigations have occurred in other parts of the
United States. Dreyer, 767 F.3d at 827–28, 833–35, 836 &
n.14. But because the same variety of case has not arisen
before and the Navy assured us at oral argument that its
policy has changed, it is not clear that suppression is
necessary on the facts of this case. That is, although the
violations were widespread, repeated violations have not
been shown, cf. Walden, 490 F.2d at 373 (“[B]ecause this
case presents the first instance of which we are aware in
which illegal use of military personnel in this manner has
been drawn into question, we decline to impose the
extraordinary remedy of an exclusionary rule at this time
. . . .”), and therefore it is not clear that suppression is
necessary to deter future violations. Roberts, 779 F.2d at
568. If, however, the same or closely similar violations were
to occur, suppression would be the appropriate remedy.



REINHARDT, Circuit Judge, concurring:

   I concur in Judge Christen’s majority opinion. I also
concur in Judge Berzon’s concurring opinion. I am in
complete agreement with both Judge Christen’s and Judge
Berzon’s views.
34               UNITED STATES V. DREYER

OWENS, Circuit Judge, joined by SILVERMAN and
CALLAHAN, Circuit Judges, concurring in the judgment:

    The majority correctly affirms the district court’s denial
of Dreyer’s motion to suppress, and recognizes that “[c]ourts
do not invoke the exclusionary rule absent compelling
circumstances.” Majority at 22–25 (citing Hudson v.
Michigan, 547 U.S. 586, 591 (2006), and Sanchez-Llamas v.
Oregon, 548 U.S. 331, 347–48 (2006)). But it says that
future violations of the Posse Comitatus Act (PCA) could
lead to suppression. Majority at 26–27 (citing United States
v. Roberts, 779 F.2d 565 (9th Cir. 1986)). I write separately
because I believe that absent express congressional
authorization, suppression is not a remedy for PCA
violations.

     Since we decided Roberts nearly 30 years ago, the
landscape on suppression has changed. The Supreme Court
has “long since rejected” the broader application of
suppression that its earlier decisions suggested, see Hudson,
547 U.S. at 591, and “imposed a more rigorous weighing of
its costs and deterrence benefits.” Davis v. United States, 131
S.Ct. 2419, 2427 (2011). Hudson and Sanchez-Llamas
instruct that before we determine whether police conduct
warrants exclusion under the facts of a particular case, we
should first decide if the violation can ever result in
suppression. Hudson, 547 U.S. at 599 (no suppression for
violation of the Fourth Amendment knock-and-announce
rule); Sanchez-Llamas, 548 U.S. at 350 (no suppression for
violation of the right to consular notification of the Vienna
Convention on Consular Relations).

    Exclusion of evidence to remedy a statutory violation is
extremely rare. The exclusionary rule applies “primarily to
                    UNITED STATES V. DREYER                             35

deter constitutional violations.” Sanchez-Llamas, 548 U.S. at
348. In “[t]he few cases in which [the Court has] suppressed
evidence for statutory violations . . . , the excluded evidence
arose directly out of statutory violations that implicated
important Fourth and Fifth Amendment interests.” Id. Those
cases are easily distinguishable from the PCA.

    In McNabb v. United States, 318 U.S. 332 (1943), and
Mallory v. United States, 354 U.S. 449 (1957), the Court
suppressed evidence obtained following violations of rules
requiring prompt presentment of an arrestee before a
magistrate judge. The “supervisory rules [at issue in McNabb
and Mallory are] responsive to the same considerations of
Fifth Amendment policy” underlying the Miranda doctrine.
Miranda v. Arizona, 384 U.S. 436, 463 (1966).

    And in Miller v. United States, 357 U.S. 301 (1958), the
Court suppressed evidence obtained after police violated the
knock-and-announce rule of 18 U.S.C. § 3109. In Wilson v.
Arkansas, 514 U.S. 927 (1995), the Court held that the
“knock and announce principle” enforced in Miller is also
“part of the Fourth Amendment reasonableness inquiry.” Id.
at 930.

    What constitutional right does the PCA implicate? The
majority finds the PCA’s “constitutional underpinnings” in
the remarks of one senator1 and the Supreme Court’s dicta


 1
    The majority also cites a Fourth Circuit case, which did not decide that
“[t]he PCA was no more than an expression of constitutional limitations,”
but only recounted congressional debates in which “several senators
expressed th[at] opinion.” United States v. Walden, 490 F.2d 372, 375
(4th Cir. 1974). Majority at 24 n.7. These senators, like the majority, did
not cite any specific constitutional text to support their opinions.
36                  UNITED STATES V. DREYER

discussing a “traditional and strong resistance of Americans
to any military intrusion into civilian affairs . . . express[ed],
for example, in the Third Amendment’s explicit prohibition
against quartering soldiers.” Laird v. Tatum, 408 U.S. 1, 15
(1972). See Majority at 24 & n.7. A statement of a senator
and dicta from Laird are not enough to convert the PCA into
the Third Amendment 2.0. The actions of various U.S.
Presidents—who at times called on the military to enforce
civil laws in the first half of the nineteenth century—strongly
suggest that the PCA is not constitutional. See H.W.C.
Furman, Restrictions upon Use of the Army Imposed by the
Posse Comitatus Act, 7 Mil. L. Rev. 85, 89 (1960), and
sources cited therein.2

    And even if we draw the lens back far enough to find an
abstract constitutional principle against military incursion
into civilian affairs, that principle cannot “fairly be
characterized as expressly designed to protect the personal
rights of [criminal] defendants.” United States v. Dreyer, 767
F.3d 826, 841 n.3 (9th Cir. 2014) (O’Scannlain, J., dissenting)
(quoting Walden, 490 F.2d at 377). Any right is “at best
remotely connected to the gathering of evidence.” Sanchez-

 2
    Indeed, the statements of other senators suggest that the PCA had far
more to do with political power than individual privacy. See, e.g., 7 Cong.
Rec. 3586 (remarks of Rep. Kimmel) (“[T]he man who holds the
Presidency of the United States against the will of the people, clearly
expressed according to law, is as surely a monarch as he who by birth or
force holds a throne . . . . The silent soldier who commanded the standing
Army riveted the chains which the people drag along in lengthening
disgrace.”); id. at 4240 (remarks of Sen. Kernan) (expressing fear that
military posse comitatus “might be used for an entire overthrow of the
rights of citizens at the polls”); id. at 4245 (remarks of Sen. Merrimon)
(alleging that the Army “has been used and prostituted to control elections
repeatedly” and explaining that the “object of [the PCA] is to prevent a
like prostitution of the Army in the future”).
                UNITED STATES V. DREYER                   37

Llamas, 548 U.S. at 349. An individual defendant like
Dreyer has no interest in what uniform the official who
monitors his public exchange of child pornography is
wearing.

    Rather than reach the issues discussed in Parts I–III, I
would follow Hudson and Sanchez-Llamas to hold that PCA
violations can never warrant suppression.        The PCA’s
abstract constitutional foundation does not bear the extreme
weight that the suppression remedy requires—far more is
needed before we elevate the PCA to the same status as the
Fourth and Fifth Amendments.

    Congress has had ample time to authorize suppression for
PCA violations, but it never has. It knows how. See, e.g., 18
U.S.C. § 2518(10)(a) (Title III); 50 U.S.C. §§ 1806, 1825 &
1845 (Foreign Intelligence Surveillance Act). Instead, it
chose to enforce the PCA with criminal sanctions. 18 U.S.C.
§ 1385. Under the Supreme Court’s current approach, we
lack the power to draft a suppression remedy that we think
Congress forgot. We must let Congress authorize the “last
resort” of suppression for PCA violations, big or small.

   Because I agree with the majority’s conclusion that
Dreyer’s suppression motion must be denied, I respectfully
concur in the judgment.
38              UNITED STATES V. DREYER

SILVERMAN, Circuit Judge, joined by CALLAHAN,
Circuit Judge, concurring in the judgment:

    I am at a loss to understand what NCIS Agent Steve
Logan did wrong here. At the outset, it is important to note
three things:

       First, as a Naval criminal investigator, Logan
       was tasked with looking for Navy personnel
       who were misusing peer-to-peer software to
       traffic in child pornography. He was not
       looking for civilians.

       Second, peer-to-peer software, by definition,
       opens up one’s computer to the world. See
       United States v. Ganoe, 538 F.3d 1117, 1127
       (9th Cir. 2008).

       Third, when Logan discovered that he had
       stumbled upon a civilian sharing child
       pornography, he dropped the investigation
       like a hot potato and did nothing more than
       turn over his findings to civilian authorities.
       He had no further involvement whatsoever in
       the investigation, search, interrogation, or
       arrest.

    In these circumstances, Logan did not violate the Posse
Comitatus-like regulations, both because his assistance of
civilian law enforcement was “indirect” and because his
limited involvement had an “independent military purpose.”
See United States v. Hitchcock, 286 F.3d 1064, 1069–70,
amended and superseded by 298 F.3d 1021 (9th Cir. 2002).
Given that Logan had a right to go on the Internet and look
                 UNITED STATES V. DREYER                     39

for those who voluntarily choose to share their computer files
with strangers – just as anyone has that right – Logan did
nothing that is prohibited, or that even required a warrant.
Anyone with the right software can do what Logan did.

    This is really no different than Shore Patrol going into a
downtown bar that’s open to the general public and looking
for misbehaving sailors. The Shore Patrol is not there to
enforce local laws, but rather “to maintain order and suppress
any unseemly conduct on the part of any” sailor on shore
leave. 32 C.F.R. § 700.922(a). If they happen to see a
civilian crime taking place in front of them, nothing prohibits
them from calling the local police, just as anyone might.

     Dreyer argues that Logan violated Navy regulations, but
tellingly, that’s not the Navy’s interpretations of its
regulations. Logan has not been disciplined for carrying out
the investigation or told that he may not continue such
investigations. Rather, the United States has argued on the
Navy’s behalf that although Logan was conducting an
investigation when he discovered Dreyer’s sharing of child
pornography, that investigation was permissible both under
NCIS’s charter (giving agents authority to “conduct[],
supervis[e], or coordinat[e] investigations of criminal activity
in programs and operations of the Department of the Navy,”
10 U.S.C. § 7480(b)) and under Department of Defense and
Navy regulations. Those regulations permit certain forms of
indirect assistance to civilian authorities, see Dep’t of
Defense Directive (“DODD”) 5525.5 E4.1.7, SECNAVINST
5820.7C § 8.d., as well as actions with the primary purpose of
furthering a military function, such as enforcing the Uniform
Code of Military Justice, which prohibits sharing of child
pornography. See Article 134, Uniform Code of Military
Justice, 10 U.S.C. § 934; DODD 5525.5, E.4.1.2.1.1;
40               UNITED STATES V. DREYER

SECNAVINST 5820.7C § 8.c.(1). Indeed, the Navy has
consistently interpreted its regulations to not prohibit similar
conduct that involved only indirect military assistance or had
an independent military purpose. See, e.g., Hitchcock, 286
F.3d at 1069–70; United States v. Chon, 210 F.3d 990 (9th
Cir. 2000) (NCIS agent’s conduct did not violate the PCA
because it had an independent military purpose); see also
Hayes v. Hawes, 921 F.2d 100, 103–04 (7th Cir. 1990) (NCIS
agents’ conduct did not violate the PCA where the agents
“merely shared information about drug activity . . . with the
police department, aided the police in surveillance . . . , made
the undercover buy, and signalled to the police when the
transaction was completed”).

    Contrary to the majority’s view, the record does not
“demonstrate[] a poor understanding of the restrictions
imposed on NCIS’s involvement in civilian law
enforcement.”        The Navy’s position that Logan’s
investigation did not violate its regulations is consistent with
its longstanding administrative practice, reasonable, and
deserving of the court’s deference. See, e.g., Lawrence v.
McCarthy, 344 F.3d 467, 473 (5th Cir. 2003) (deferring to
military court interpretations on the basis that they require
“interpretation of military forms and standard operating
procedures with which we are comparatively less well-
versed”). Branches of the military promulgate and administer
their own regulations, which the Navy has done here; a
reasonable interpretation by the Navy of its own regulation
must stand even if there are competing interpretations. See
Champagne v. United States, 35 Fed. Cl. 198, 210 (1996),
aff’d, 136 F.3d 1300 (Fed. Cir. 1998) (“[W]hen the meaning
of military regulations and instructions are at issue, the armed
service’s own interpretation must be given controlling weight
                 UNITED STATES V. DREYER                      41

and deference, especially when it has been consistently
interpreted over a long period of time.”). As I have
emphasized, “[t]he military’s considered professional
judgment is not lightly to be overruled by the judiciary.”
Meinhold v. U.S. Dep’t of Def., 34 F.3d 1469, 1476 (9th Cir.
1994) (internal quotations and citation omitted). The Navy,
in declining to discipline Agent Logan for his investigation,
has implicitly interpreted the regulations to conclude that the
regulation was not violated. That reasonable interpretation
deserves the court’s deference.

    But even if zero deference were owed to the Navy’s
interpretation of its own regulations, I would hold that there
was no violation. As sketched out above, when Logan started
his investigation, it was solely with the aim of identifying
Navy or other military personnel who were sharing child
pornography online, in violation of the Uniform Code of
Military Justice. Such an investigation is clearly in service of
a legitimate Navy interest. Although Logan came upon a
civilian, defendant Dreyer, distributing child pornography on
a peer-to-peer file sharing service as part of this process, that
discovery was not Logan’s aim. Rather, as demonstrated by
Logan’s prompt action in turning over the investigation of
Dreyer to local civilian law enforcement, his sole purpose
was to “further[] a military or foreign affairs function of the
United States,” DODD 5525.5, E.4.1.2.1; SECNAVINST
5820.7C at 8(c)(1): identifying military service members who
are illegally sharing child pornography. Logan had no
interest in or jurisdiction over Dreyer’s transgressions, and he
did nothing more than bring them to the attention of the
42              UNITED STATES V. DREYER

relevant civilian authorities, and then wash his hands of the
matter. Since Logan’s investigation had this independent
military purpose, it did not violate the regulations.

   I concur in the judgment affirming the denial of the
motion to suppress.
