United States v. Andrew Katakis , 800 F.3d 1017 ( 2015 )


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  •                        FOR PUBLICATION
    UNITED STATES COURT OF APPEALS
    FOR THE NINTH CIRCUIT
    UNITED STATES OF AMERICA,                     No. 14-10283
    Plaintiff-Appellant,
    D.C. No.
    v.                      2:11-cr-00511-WBS-2
    ANDREW B. KATAKIS,
    Defendant-Appellee.                     OPINION
    Appeal from the United States District Court
    for the Eastern District of California
    William B. Shubb, Senior District Judge, Presiding
    Argued and Submitted
    May 15, 2015—San Francisco, California
    Filed August 31, 2015
    Before: Marsha S. Berzon and N. Randy Smith, Circuit
    Judges and Raner C. Collins,* Chief District Judge.
    Opinion by Judge N.R. Smith
    *
    The Honorable Raner C. Collins, Chief District Judge for the U.S.
    District Court for the District of Arizona, sitting by designation.
    2                  UNITED STATES V. KATAKIS
    SUMMARY**
    Criminal Law
    The panel affirmed the district court’s order granting
    Andrew Katakis a judgment of acquittal after a jury convicted
    him of obstruction of justice, in violation of 18 U.S.C.
    § 1519, in a case in which Katakis, after learning that federal
    authorities had subpoenaed his bank records in connection
    with an investigation into a scheme to rig bids at foreclosure
    auctions, installed onto his home computer a program
    designed to wipe hard drives clean of all information.
    The panel affirmed because the evidence was insufficient
    to show that Katakis actually deleted electronic records or
    files, and because proving that Katakis moved emails from an
    email client’s inbox to the deleted items folder does not
    demonstrate Katakis actually concealed those emails within
    the meaning of § 1519.
    COUNSEL
    Adam D. Chandler (argued), Attorney; William J. Baer,
    Assistant Attorney General; Brent Snyder, Deputy Assistant
    Attorney General; Anna Tryon Pletcher, Tai S. Milder, May
    Lee Heye, Kelsey C. Linnett, Kristen C. Limarzi, and James
    Joseph Fredricks, Attorneys, United States Department of
    Justice, Antitrust Division, Washington, D.C., for Plaintiff-
    Appellant.
    **
    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. KATAKIS                      3
    Elliot R. Peters (argued), Steven A. Hirsch, Jennifer A.
    Huber, and Elizabeth K. McCloskey, Keker & Van Nest LLP,
    San Francisco, California, for Defendant-Appellee.
    OPINION
    N.R. SMITH, Circuit Judge:
    The Government appeals the district court’s order
    granting Katakis’s Fed. R. Crim. P. 29 motion. The district
    court vacated Katakis’s conviction and entered a judgment of
    acquittal, holding that the evidence was insufficient to
    support the jury’s verdict. The Government’s theory of
    liability collapsed during trial, and the Government now
    raises several alternative theories to try and rescue the
    conviction. The evidence was insufficient to show that
    Katakis actually deleted electronic records or files. Further,
    proving Katakis moved emails from an email client’s inbox
    to the deleted items folder does not demonstrate Katakis
    actually concealed those emails within the meaning of
    § 1519. We affirm.
    BACKGROUND
    This case arises from an investigation by federal
    authorities into a scheme to rig bids at foreclosure auctions in
    2008 and 2009. By 2010, the investigation focused on
    Andrew Katakis as one of the primary real estate investors
    helming the conspiracy. On September 1, 2010, Katakis
    received a letter from his bank informing him that
    federal investigators had subpoenaed his bank records.
    On September 3, 2010, Katakis purchased, downloaded,
    and installed a program called DriveScrubber 3
    4               UNITED STATES V. KATAKIS
    (“DriveScrubber”) onto his home computer, a Dell
    (“Katakis’s Dell”). DriveScrubber is a program designed to
    wipe hard drives clean of all information. DriveScrubber
    may be used to overwrite all of the information in a hard
    drive’s unallocated or “free” space. Free space is the portion
    of the hard drive that is not allocated for the use of the
    computer’s programs or operating system; items that are
    deleted by a user may “fall” into the free space. There, the
    deleted item is not actually removed from the computer right
    away; the space it occupies on the hard drive has simply been
    made available to be overwritten. Instead of waiting for
    another file to overwrite the deleted file by chance,
    DriveScrubber actively overwrites all data in the unallocated
    space of a hard drive, permanently erasing any files that had
    fallen into the free space. Once a file is overwritten by
    DriveScrubber, it is impossible to retrieve it.
    Katakis’s business partner and alleged co-conspirator,
    Steve Swanger, kept two computers at their office: an ASUS
    (“Swanger’s ASUS”), and a Dell (“Swanger’s Dell”).
    Swanger’s Dell was used primarily for emailing with Katakis,
    and Swanger’s ASUS was used for general internet searching.
    On Saturday, September 4, 2010, Katakis summoned
    Swanger to their business office. Katakis told Swanger that
    he wanted to install a “scrubber program” on their computers
    and that there was “nothing wrong with us cleaning our
    computers.” Swanger observed Katakis use Swanger’s
    ASUS and perform a search for emails involving members
    of the bid-rigging conspiracy. At 4:40 pm, Katakis installed
    DriveScrubber on the Swanger ASUS. This copy of
    DriveScrubber was different from the one installed on
    UNITED STATES V. KATAKIS                           5
    Katakis’s Dell.1 Swanger did not observe any deletions on
    the ASUS; he only observed Katakis “clicking and moving
    things around.”
    Katakis then moved to Swanger’s Dell and installed
    DriveScrubber at 4:47 pm. The Swanger Dell had 4,000
    emails on it, as Swanger was not in the habit of regularly
    deleting his emails. Swanger kept hard copies of some
    important emails, because he feared Katakis might try and
    wipe clean the hard drives some day. Swanger observed
    Katakis checking boxes on various emails and unchecking
    those emails that Katakis believed that Swanger needed.
    Katakis gave up sorting the emails after about five minutes
    and pressed the delete key. After seeing that it would take a
    long time for the emails to be deleted, Katakis went home.
    When he returned to the office on Monday, Swanger noticed
    that almost all of the emails on his Dell had been deleted
    from his email inbox.
    At 5:37 pm on September 4, 2010, the same copy of
    DriveScrubber that was installed on Katakis’s Dell was
    installed on the office’s mail server (“GD Mail Server”). The
    server managed all email sent or received in the office
    through the Microsoft Outlook program. The GD Mail
    Server was operated by a program called Exchange. Katakis
    had the authority to install programs on the GD Mail Server
    and knew that DriveScrubber had been installed on it.
    1
    Although the program installed on Katakis’s Dell and Swanger’s
    ASUS was the same, the evidence indicated that two different copies were
    used. The version of DriveScrubber installed on Swanger’s ASUS and
    Swanger’s Dell was purchased using Swanger’s credit card.
    6                  UNITED STATES V. KATAKIS
    The Government seized the four computers in the course
    of its investigation into the bid-rigging scheme. When
    examining Swanger’s Dell, the Government discovered ten
    incriminating emails that implicated Katakis in the
    conspiracy. Katakis was either a sender or recipient of all ten
    emails. Swanger was also either the sender or recipient of all
    ten emails. The emails were discovered in the deleted items
    folder in Swanger’s email client. Metadata attached to the
    emails showed that the emails had passed through the GD
    Mail Server and that Katakis had received and opened all of
    them. Special Agent Scott Medlin conducted a forensic
    analysis of the other three computers. Because Katakis’s
    Dell, Swanger’s ASUS, and the GD Mail Server were all part
    of the email network shared with Swanger’s Dell, Medlin
    expected to find traces of the ten emails on these computers.
    Medlin was unable to locate any trace of the ten incriminating
    emails, but did not think that enough time had passed for all
    traces of the emails to be removed by the gradual automatic
    overwriting process, leading him to believe that Katakis had
    destroyed them using DriveScrubber.
    Based on the discrepancy between the presence of the ten
    incriminating emails on Swanger’s Dell but not on the other
    computers, the Government sought and obtained an
    indictment charging Katakis with obstruction of justice, in
    violation of 18 U.S.C. § 1519.2 The indictment alleged that
    Katakis “deleted and caused others to delete electronic
    records and documents. KATAKIS also installed and used
    and caused others to use a software program that overwrote
    2
    Katakis was also charged with bid-rigging, in violation of 15 U.S.C.
    § 1, and conspiracy to commit mail fraud, in violation of 18 U.S.C.
    § 1349. The jury found Katakis guilty of bid-rigging. That conviction is
    not before us.
    UNITED STATES V. KATAKIS                    7
    deleted electronic records and documents so that they could
    not be viewed or recovered.” Notably, the indictment failed
    to charge attempt, thus committing the Government to prove
    actual deletion.
    The Government proceeded to trial on the theory that
    Katakis ran the DriveScrubber program on his Dell,
    Swanger’s ASUS, and the GD Mail Server, to erase all traces
    of the ten incriminating emails. The Government’s key
    witness was Medlin, who testified as an expert. Medlin
    testified that Katakis “double-deleted” emails; that is, he
    deleted them once from the mail client and then again when
    he emptied the deleted items folder. After they were double
    deleted, the emails fell into the free space, where Medlin
    opined that they were irretrievably overwritten by
    DriveScrubber.
    Katakis called Don Vilfer as a rebuttal expert. Vilfer
    testified that Medlin’s theory of what happened to double-
    deleted emails was incorrect, based on how the Exchange
    program on the GD Mail Server worked. According to
    Vilfer, a double-deleted email would not fall into the free
    space, as Medlin testified, but would remain within the
    portion of the hard drive allocated for the Exchange database.
    The crux of Vilfer’s testimony was that, given how the
    Exchange program operated, it would be impossible for
    DriveScrubber to overwrite any double-deleted emails,
    including the ten incriminating emails that were at the heart
    of the Government’s case. Vilfer further noted that the
    Exchange program itself removed double-deleted emails after
    a certain period of time, usually fourteen days. Vilfer
    testified that he was able to recover thousands of double-
    deleted emails, but he could not find the ten incriminating
    emails. Vilfer agreed with Medlin that it was suspicious that
    8               UNITED STATES V. KATAKIS
    there were no traces of the ten incriminating emails on any
    computer other than Swanger’s Dell. However, he explained
    that absence by opining that the ten incriminating emails
    (including metadata) had been fabricated. The defense
    sought to draw an inference that Swanger fabricated the ten
    incriminating emails and the metadata indicating Katakis had
    seen them in order to implicate Katakis.
    In rebuttal, Medlin admitted that Vilfer’s testimony was
    correct: it was impossible for DriveScrubber to have deleted
    the ten incriminating emails. Medlin testified that his opinion
    was unchanged, because DriveScrubber could have deleted
    transmission logs associated with the ten incriminating
    emails. Vilfer testified in response that deleting the
    transmission logs would not have deleted the emails
    themselves.
    By the time of its closing argument, the Government’s
    primary theory of the case had collapsed. In closing, the
    Government offered two theories of liability to the jury.
    First, the Government argued a purely circumstantial case.
    The ten incriminating emails were present on Swanger’s Dell,
    and both experts testified that they would have expected to
    find them on the other computers. The only logical inference,
    the Government reasoned, was that Katakis had somehow
    deleted them. Second, the Government relied on Swanger’s
    testimony for an alternative theory of liability. Under this
    theory, DriveScrubber was only relevant to prove intent. If
    the jury believed Swanger’s testimony that Katakis hit the
    delete key and sent emails on Swanger’s Dell to the deleted
    items folder, this was legally sufficient to convict Katakis of
    obstruction of justice. The Government alluded to an
    additional theory of liability in its rebuttal, arguing that
    UNITED STATES V. KATAKIS                    9
    Katakis used DriveScrubber to delete remnants of the emails
    (the transmission logs).
    The jury convicted Katakis of obstruction of justice.
    Katakis filed a motion for judgment of acquittal, alleging,
    among other things, that the evidence was insufficient to
    convict him. The district court agreed, and, after carefully
    evaluating each of the Government’s theories of liability and
    finding them all insufficient to sustain a conviction for
    obstruction of justice, vacated Katakis’s conviction and
    entered a judgment of acquittal. The Government appeals.
    DISCUSSION
    We review de novo the district court’s order granting a
    judgment of acquittal pursuant to Fed. R. Crim. P. 29. United
    States v. Sanchez, 
    639 F.3d 1201
    , 1203 (9th Cir. 2011). Our
    review “is governed by Jackson v. Virginia, which requires a
    court of appeals to determine whether ‘after viewing the
    evidence in the light most favorable to the prosecution, any
    rational trier of fact could have found the essential elements
    of the crime beyond a reasonable doubt.’” United States v.
    Nevils, 
    598 F.3d 1158
    , 1163–64 (9th Cir. 2010) (en banc)
    (citation omitted) (quoting Jackson v. Virginia, 
    443 U.S. 307
    ,
    319 (1979)). Nevils prescribes the structure of our inquiry:
    “[f]irst, a reviewing court must consider the evidence
    presented at trial in the light most favorable to the
    prosecution.” 
    Id. at 1164.
    “Second, . . . the reviewing court
    must determine whether this evidence, so viewed, is adequate
    to allow ‘any rational trier of fact to find the essential
    elements of the crime beyond a reasonable doubt.’” 
    Id. (alterations omitted)
    (quoting 
    Jackson, 443 U.S. at 319
    ).
    “[T]he government does not need to rebut all reasonable
    interpretations of the evidence that would establish the
    10               UNITED STATES V. KATAKIS
    defendant’s innocence, or ‘rule out every hypothesis except
    that of guilt beyond a reasonable doubt.’” 
    Id. (quoting Jackson,
    443 U.S. at 326). That said, “evidence is
    insufficient to support a verdict where mere speculation,
    rather than reasonable inference, supports the government’s
    case, or where there is a ‘total failure of proof of a requisite
    element.’” 
    Id. at 1167
    (citations and alterations omitted)
    (quoting Briceno v. Scribner, 
    555 F.3d 1069
    , 1079 (9th Cir.
    2009)).
    Katakis was convicted of obstruction of justice, in
    violation of 18 U.S.C. § 1519. That statute provides:
    Whoever knowingly alters, destroys,
    mutilates, conceals, covers up, falsifies, or
    makes a false entry in any record, document,
    or tangible object with the intent to impede,
    obstruct, or influence the investigation or
    proper administration of any matter within the
    jurisdiction of any department or agency of
    the United States . . . or contemplation of any
    such matter or case, shall be fined under this
    title, imprisoned not more than 20 years, or
    both.
    18 U.S.C. § 1519. Section “1519 was intended to prohibit, in
    particular, corporate document-shredding to hide evidence of
    financial wrongdoing.” Yates v. United States, 
    135 S. Ct. 1074
    , 1081 (2015). In order to prove a violation of § 1519,
    the Government must show that the defendant (1) knowingly
    committed one of the enumerated acts in the statute, such as
    destroying or concealing; (2) towards “any record, document,
    or tangible object”; (3) with the intent to obstruct an actual or
    UNITED STATES V. KATAKIS                     11
    contemplated investigation by the United States of a matter
    within its jurisdiction.
    We have only one question regarding the sufficiency of
    the evidence before us: whether the Government carried its
    burden to show actual destruction or concealment. There is
    no dispute that there was sufficient evidence for a rational
    juror to conclude that the Government satisfied the third
    element, that Katakis intended that his actions would obstruct
    the investigation into the bid-rigging scheme. A rational
    juror also could have concluded that Katakis knew or
    believed that his actions could destroy or conceal the ten
    incriminating emails. However, the Government failed to
    charge Katakis with attempted obstruction in the indictment.
    Therefore, in order to secure a conviction, the Government
    was required to prove that Katakis actually destroyed or
    concealed “electronic records and documents.”
    In light of Medlin’s retraction, there was no evidence
    upon which a reasonable juror could conclude that Katakis
    used DriveScrubber to irretrievably overwrite (that is, destroy
    or conceal) the ten incriminating emails from the free space
    of any of the computers. The theory that the Government
    presented in its case-in-chief cannot support Katakis’s
    conviction. Nevertheless, the Government contends that the
    district court erred, because there are three other theories of
    liability that the jury could have credited that satisfy the
    elements of the statute: (1) Katakis used DriveScrubber to
    delete the transmission logs belonging to the ten
    incriminating emails; (2) Katakis double deleted emails on
    his Dell, Swanger’s ASUS, and the GD Mail Server; or
    (3) Katakis single-deleted emails on Swanger’s Dell, moving
    those emails from the inbox to the deleted items folder. For
    the reasons set out below, we agree with the district court that
    12                 UNITED STATES V. KATAKIS
    the evidence was insufficient to convict Katakis of
    obstruction of justice on any of these theories.
    A. DriveScrubber Theory
    The first theory that the Government advances relies on
    testimony given by Medlin during rebuttal to the effect that,
    although Katakis could not have deleted the ten incriminating
    emails themselves, he could have deleted transmissions logs
    generated by the emails.3 Forced to retract his testimony that
    the ten incriminating emails could have been deleted by
    DriveScrubber, Medlin testified that he did not retract his
    opinion that Katakis used DriveScrubber to destroy electronic
    records, because he likely used DriveScribber to overwrite
    transmission logs generated by the emails.
    Medlin testified that transmission logs are generated daily
    by the Exchange system. These logs resided outside the
    Exchange database (so they were separate from the emails
    themselves), and would “remain” in the program for a period
    of time before falling off into the free space to be made
    available for the DriveScrubber program to overwrite.
    Medlin could not testify as to how long it took for the
    transmission logs to fall into free space; he noted that there
    was a default time programmed into the Exchange database
    (although he did not recall what the default was), but that
    time could be changed by the system administrator. On
    3
    The Government likely waived this theory by failing to present it to the
    district court as part of its opposition to Katakis’s Rule 29 motion. See
    United States v. Piazza, 
    647 F.3d 559
    , 565 (5th Cir. 2011) (holding that
    government waived an argument it failed to present in its response to
    defendant’s motion for new trial). However, Katakis has not asserted
    waiver on appeal. Therefore, Katakis has “waive[d] waiver.” Tokatly v.
    Ashcroft, 
    371 F.3d 613
    , 618 (9th Cir. 2004).
    UNITED STATES V. KATAKIS                   13
    cross-examination, Medlin admitted that he did not perform
    an investigation into whether a default time was even set on
    the Exchange database. Medlin also testified that he did not
    perform any investigation as to whether any user had entered
    a command causing the Exchange database to “clean up” the
    transmission logs and let them enter free space.
    Although the Government is entitled to every reasonable
    inference from the evidence, a conviction may not be based
    on mere speculation. 
    Nevils, 598 F.3d at 1167
    . “[A]
    reasonable inference is one that is supported by a chain of
    logic, rather than mere speculation dressed up in the guise of
    evidence.” United States v. Del Toro-Barboza, 
    673 F.3d 1136
    , 1144 (9th Cir. 2012) (quotation marks and alteration
    omitted) (quoting Juan H. v. Allen, 
    408 F.3d 1262
    , 1277 (9th
    Cir. 2005)). The logical chain supporting the Government’s
    theory is as follows: (1) Katakis downloaded and installed
    DriveScrubber, which, along with Swanger’s testimony,
    demonstrates his intent to destroy incriminating emails and
    other electronic records; (2) DriveScrubber could only
    destroy the emails if they were in the free space; (3) the
    transmission logs enter the free space through one of two
    ways, either at the default time or through user action;
    (4) both agents testified that they expected to find email
    remnants, including transmission logs, on the computers; and
    (5) no email remnants were found. From this chain of logic,
    the Government contends a reasonable juror could have
    concluded that Katakis destroyed the logs using
    DriveScrubber.
    However, the Government’s chain of logic misses an
    important link: there is no evidence whatsoever that the
    transmission logs were made available, in any manner, for
    DriveScrubber to overwrite. The Government invited the
    14                  UNITED STATES V. KATAKIS
    jury to speculate as to whether the transmission logs entered
    the free space; the Government’s own expert could not testify
    that they ever did. The transmission logs theory was
    developed entirely in rebuttal in an attempt to save the
    Government’s case. Make no mistake, the Government’s
    original plan failed. Indeed, the full theory presented here did
    not crystallize as an argument until this appeal. The
    Government did not argue in its closing that deletion of the
    transmission logs could, under § 1519, constitute the
    destruction of electronic records; instead, the Government
    asserted in its rebuttal that the absence of the logs was
    evidence DriveScrubber was run to delete the emails. In light
    of the way that this case was tried, it is not surprising that the
    Government’s transmission log theory was half-baked.
    Medlin admitted he never even investigated the possibility
    that the transmission logs were removed to the free space
    where they could have been deleted by DriveScrubber. In the
    absence of that evidence, the jury was left to speculate not
    only regarding how the transmission logs entered the free
    space but if they ever did so. There was nothing preventing
    the Government from having Medlin investigate this question
    and provide evidence, even circumstantial evidence, from
    which the jury could make the desired inference. However,
    that evidence was entirely lacking in this case.4
    4
    The Government’s failure to develop this theory may have led to
    another deficiency. Section 1519 requires that the defendant act
    knowingly. A defendant “is said to act knowingly if he is aware ‘that that
    result is practically certain to follow from his conduct, whatever his desire
    may be as to that result.’” United States v. Bailey, 
    444 U.S. 394
    , 404
    (1980) (quoting United States v. U.S. Gypsum Co., 
    438 U.S. 422
    , 445
    (1978)). “[T]he term ‘knowingly’ merely requires proof of knowledge of
    the facts that constitute the offense.” Bryan v. United States, 
    524 U.S. 184
    , 193 (1998). The Government failed to provide any evidence that
    Katakis knew that transmission logs, a category of electronic record
    UNITED STATES V. KATAKIS                          15
    In the absence of that critical link in the logical chain of
    inference, the evidence was not sufficient to convict Katakis
    on this theory.
    B. Double Deletion Theory
    The Government’s second theory contends that a rational
    juror could have found that Katakis double deleted emails on
    all of the computers except Swanger’s Dell, and that, if he did
    so with the requisite intent, he violated the statute. We shall
    assume, without deciding, that double deletion would
    constitute the requisite concealment or destruction element of
    § 1519. However, even with that assumption, no reasonable
    juror could have found on this record that the Government
    carried its burden to show that double deletion actually
    occurred.
    In this context, “double deletion” means that the
    Government sought to first prove that Katakis pressed the
    delete key after selecting emails in the inbox of the email
    client, moving them to the deleted items folder or a recycling
    bin. The Government’s theory asserted that Katakis then
    deleted the emails a second time, with the intent that they
    would fall into the free space of the hard drive so they could
    be permanently overwritten by DriveScrubber. This theory
    relies on two pieces of evidence, one direct and one
    circumstantial. First, the Government points to direct
    evidence that Swanger observed Katakis deleting emails.
    wholly separate and distinct from the emails, even existed. There is no
    evidence that Katakis knowingly destroyed these records. It is not clear
    to us that Katakis could have been aware that the destruction of the
    transmission logs was “practically certain” to result from running
    DriveScrubber.
    16              UNITED STATES V. KATAKIS
    Given that fact, and the evidence that Katakis installed
    DriveScrubber, the Government contends that a rational juror
    could have inferred that he had double deleted the emails to
    make them available for DriveScrubber to overwrite. Second,
    the Government argues that a rational juror could have
    inferred double deletion from the fact that the ten
    incriminating emails were not found on any computer other
    than Swanger’s Dell.
    There are again significant factual flaws in the
    Government’s argument. First, Swanger never offered any
    testimony that he observed Katakis do anything on Katakis’s
    Dell or the GD Mail Server. With regard to Swanger’s
    ASUS, Swanger declined to testify that he actually observed
    Katakis deleting anything, much less double-deleting the
    emails. Swanger testified only that he saw Katakis “clicking
    and moving things around.” Swanger never testified that he
    noticed that any files or emails were missing on his ASUS,
    whereas he testified that many emails were missing from his
    Dell.
    In the absence of direct evidence of double deletion, the
    Government relies on a chain of circumstantial inferences
    that a rational juror would have to credit to find that Katakis
    double deleted the emails. The rational juror would first have
    to find that Katakis intended to destroy the ten incriminating
    emails; as to that point, there was sufficient evidence—the
    installation of DriveScrubber. But the evidence that he
    carried out this intent comes from a single fact: that the ten
    incriminating emails were not found on Katakis’s Dell,
    Swanger’s ASUS, or the GD Mail Server. Both experts
    testified that they expected to find the emails on those
    computers. In their absence, the Government argues that a
    rational juror would be entitled to conclude that Katakis
    UNITED STATES V. KATAKIS                    17
    double deleted the emails. However, the Government never
    provided the jury with any mechanism that would explain
    how Katakis removed the emails from the three computers,
    given that, as both experts ultimately agreed, double deletion
    on the email client does not send an email to the free space,
    where DriveScrubber could have destroyed it.
    The Government’s theory is analogous to one that we
    rejected in United States v. Lo, 
    231 F.3d 471
    (9th Cir. 2000).
    In Lo, the defendant was charged with mail fraud, which
    required the government to prove that the defendant actually
    mailed a document in furtherance of the fraud scheme. 
    Id. at 475.
    The only evidence that the government could muster to
    show that the document was mailed was testimony from an
    employee that a document Lo submitted would have been
    mailed in the ordinary course of its business. 
    Id. at 475–76.
    No one testified that they ever saw the document, no one
    testified that they had sent it, there was no record it had
    existed, and no one testified to receiving it. 
    Id. at 476.
    We
    found that this evidence was insufficient, and the inferences
    that the jury was required to draw too “attenuated,” to support
    a conviction for mail fraud. 
    Id. at 477.
    In Lo, we were
    particularly concerned that the evidence of fraudulent intent,
    for which there was sufficient evidence, might lead a juror to
    overlook the factual gaps in the government’s proof. 
    Id. We are
    faced with a similar concern here. In Lo, there
    was no evidence that the document in question even existed,
    
    id. at 476,
    while there were specific emails at issue in the
    record here. But as in Lo, the evidence of the crime itself was
    attenuated. There was no direct evidence in the record that
    Katakis deleted the emails on his Dell, Swanger’s ASUS, or
    the GD Mail Server, much less double-deleted them. The
    evidence of Katakis’s intent was truly overwhelming, but the
    18               UNITED STATES V. KATAKIS
    Government’s attempts to prove that he actually performed
    the acts of which he was accused, were incredibly weak. The
    Government’s primary theory, that Katakis double deleted the
    emails and then used DriveScrubber to overwrite them,
    completely collapsed. Had this theory been available to the
    jury, the jurors would have been entitled to conclude that
    Katakis double deleted the emails, because, according to
    Medlin’s initial testimony, this step is the necessary predicate
    for making the emails available for DriveScrubber to
    overwrite. The Government conceded that it was impossible
    for DriveScrubber to overwrite the emails, but only the
    possibility that DriveScrubber overwrote the emails supported
    the inference of double deletion. Otherwise, both experts
    testified that they would have expected to find the emails.
    The Government now argues that the jury could have
    inferred double deletion from the fact that the ten
    incriminating emails could not be found on any of the three
    computers, raising an inference that they were somehow
    destroyed by a process that included double deletion. Under
    Lo, this fact might be enough, if the Government had
    provided any explanation that the jury could credit to explain
    why the emails were not present. The Government was
    entirely unable to explain (a) at trial, (b) in closing, (c) before
    the district court, or now (d) on appeal, where the ten
    incriminating emails, their traces, or their remnants went.
    Indeed, the one theory that the Government provided, that
    DriveScrubber was used to overwrite the emails, was
    discredited and withdrawn. At closing, the Government
    relied on Medlin’s eleventh-hour theory that email remnants,
    not the emails themselves, had been overwritten by
    DriveScrubber.       After the collapse of the primary
    DriveScrubber theory, the Government was left with no
    UNITED STATES V. KATAKIS                              19
    theory at all to explain what happened to the emails and why
    neither expert could find any trace of them.5
    The absence of the emails eliminates the logical inference
    of double-deletion. Both experts testified that they expected
    to find the emails if they were double deleted, but they also
    explained that it was impossible for DriveScrubber to delete
    them. As a result, double deletion cannot explain the absence
    of the emails. That absence, far from corroborating the
    Government’s theory, demonstrates a gaping hole in its logic.
    Without a mechanism to make double deletion a necessary
    inference to the cause of the emails’ absence, a rational juror
    could not conclude, beyond a reasonable doubt, that double
    deletion occurred. In essence, there was no evidence to
    support the Government’s theory, only speculation that relied
    heavily on evidence of Katakis’s intent while absolving the
    Government of its obligation to prove the act. In short, there
    was no evidence, direct or circumstantial, that the emails in
    question were in fact double deleted.
    5
    The only other potential theory disclosed by the record was that the
    email client or Exchange automatically overwrote the emails after they
    were double deleted. The Government does not press this theory on
    appeal and it did not raise it to the jury at trial. Nevertheless, we conclude
    that this possibility also does not raise an inference of double deletion and
    it does not explain the absence of any trace of the ten emails. There was
    no evidence at all of what the time frame for such automatic deletion
    would have been, or even whether the automatic deletion feature was
    activated on the relevant computers. Further, both experts testified that
    they would have expected to find, at the very least, traces of the ten emails
    on the computers in question. There was no evidence in the record that
    the automatic deletion process, as opposed to a program like
    DriveScrubber, would have eliminated all traces of the emails.
    Ultimately, there is no explanation in the record for why none of the ten
    emails, or any trace of them, could not be found on any computer,
    including the GD Mail Server.
    20               UNITED STATES V. KATAKIS
    We emphasize we are not requiring that the Government
    disprove innocent explanations why the emails were not
    present on any of the three computers. The Government is
    correct that, following our decision in Nevils, authority
    indicating that we may find the evidence insufficient to
    convict where there is an innocent explanation for inculpatory
    conduct, such as United States v. Delgado, 
    357 F.3d 1061
    ,
    1068 (9th Cir. 2004), is no longer viable. See 
    Nevils, 598 F.3d at 1167
    (overruling precedents that “strayed from
    the test established in Jackson, and made ‘plausible’
    exculpatory constructions” of the evidence). However, this
    was not a case where a government theory competed with a
    defense theory. Instead, the Government in this case
    presented no theory at all to explain to the jury how the
    emails were destroyed, a fact that was critical to the chain of
    inferences required to find beyond a reasonable doubt that
    Katakis double deleted the emails. In essence, the
    Government again invited the jury to do what Nevils forbids:
    engage in mere speculation on critical elements of proof. 
    Id. C. Single
    Deletion Theory
    The Government’s final theory relies wholly on
    Swanger’s testimony. Swanger testified that he observed
    Katakis press the delete key after screening emails on
    Swanger’s Dell. The Government argued in closing that all
    the jury needed to find in order to convict Katakis was that he
    pressed the delete key, thereby moving the emails from the
    inbox on Swanger’s Dell to the deleted items folder.
    The evidence was sufficient for the Government to prove
    the fact underlying this legal theory; all the jury had to do was
    credit Swanger’s testimony. “It is well established that the
    uncorroborated testimony of a single witness may be
    UNITED STATES V. KATAKIS                     21
    sufficient to sustain a conviction.” United States v. Dodge,
    
    538 F.2d 770
    , 783 (8th Cir. 1976). Further, the ten
    incriminating emails were discovered in the deleted items
    folder of Swanger’s Dell, raising at least a colorable inference
    that Katakis deleted them. The district court recognized that
    the evidence was sufficient to prove the fact that Katakis
    single deleted the emails. However, the district court held
    that single deletion was not sufficient to give rise to liability
    under §1519. We agree.
    The Government argues that moving the ten incriminating
    emails from the inbox to the deleted items folder was
    sufficient to “conceal” them within the meaning of § 1519.
    Once again, the Government is forced into this strained
    position by the collapse of its original theory at trial. We
    have been unable to locate any case law, and the Government
    provides none, providing a definition for concealment under
    § 1519. “Conceal” is not a term of art, and it is unambiguous,
    so we are obligated to give the term its plain meaning. See
    Williams v. Paramo, 
    775 F.3d 1182
    , 1188 (9th Cir. 2015)
    (“Because we assume that Congress means what it says in a
    statute, the ‘plain meaning of a statute controls where that
    meaning is unambiguous.’”) (quoting Khatib v. Cty. of
    Orange, 
    639 F.3d 898
    , 902 (9th Cir. 2011) (en banc)).
    “Conceal” means “to prevent disclosure or recognition of;
    avoid revelation of; refrain from revealing recognition of;
    draw attention from; treat so as to be unnoticed; to place out
    of sight; withdraw from being observed; shield from vision or
    notice.” Webster’s Third New International Dictionary
    (1993). The Government would have us adopt a definition of
    “conceal” such that when a defendant removes something
    from its “ordinary place of storage” making the thing “more
    difficult to find,” he may be liable under § 1519. Indeed, the
    Government would define concealment as “anything that
    22                 UNITED STATES V. KATAKIS
    makes something harder for a casual onlooker to see, observe,
    or notice.” The Government places special emphasis on the
    fact that Katakis “dumped” the emails “in the digital
    equivalent of a trash receptacle.”
    The Government primarily relies on a Third Circuit case,
    United States v. Lessner, 
    498 F.3d 185
    (3d Cir. 2007), to
    support its interpretation. In that case, federal agents arrived
    at Lessner’s place of work as part of their investigation and
    observed her placing an incriminating appointment book into
    a trash can. 
    Id. at 191.
    Lessner also removed a stack of files
    from a locked filing cabinet and placed them on her desk. 
    Id. Lessner then
    contacted other individuals involved in her
    scheme, and they destroyed the files. 
    Id. On the
    basis of
    these acts, the government charged Lessner with violating
    18 U.S.C. § 1519. The Third Circuit held that placing the
    incriminating appointment book in the trash can constituted
    only “an attempt to ‘conceal’ and ‘cover up’ a ‘record.’”6 
    Id. at 196
    n.5. Therefore, Lessner does not support the
    Government’s position. Quite the opposite: removing the
    incriminating appointment book from the place it would
    normally be found and depositing it in a place that would
    have made it somewhat harder for investigating agents to find
    it was not sufficient to actually conceal the book.
    6
    The Third Circuit noted that “Lessner’s act of disposal—which seems
    clearly to be a form of ‘destruction’—falls within the proscriptions of the
    statute.” 
    Lessner, 498 F.3d at 196
    n.5. Given the language quoted above,
    we take the Third Circuit’s language to mean that, had the appointment
    book been taken out with the trash, then it would have eventually been
    destroyed. It is nonsensical that the Third Circuit could have meant that
    the incriminating appointment book could have been actually destroyed
    simply by placing it a trash can.
    UNITED STATES V. KATAKIS                    23
    The Government makes much of the fact that a jury could
    find that Katakis placed the emails into the deleted items
    folder, which the Government analogizes to a real world,
    physical trash can. But a deleted items folder in an email
    client is not like a trash can. Ordinarily, a trash can is
    eventually emptied into a larger receptacle, the trash is
    mingled with other garbage, and the garbage is then either
    destroyed or placed in a location in which it is extremely
    difficult to find any particular item. On Katakis’s computer,
    in contrast, an email placed in the deleted items folder
    remained in that folder unless a user took further action. As
    Katakis persuasively argues, all that he accomplished by
    single deleting the emails was moving them from one folder
    to another. In essence, Katakis placed the ten incriminating
    emails into an email folder that is by default not displayed to
    the user. But the first place that any competent investigator
    would look for emails that are not in the inbox is in the
    deleted items folder. This degree of concealment is not
    sufficient to satisfy § 1519.
    In making this determination, we are cognizant of the
    Government’s objection that focusing the inquiry too heavily
    on the potential actions of the investigator may create a
    “Catch-22.” It cannot be the case that, in order to prove
    concealment, the item being concealed must never be found.
    However, there must be more than the de minimis standard
    the Government urges. The Government’s approach would
    all but eliminate the act requirement from the statute: so
    much as taking an incriminating document from the surface
    of a desk and placing it in a drawer, or putting another folder
    on top of it, would expose a defendant to a twenty-year prison
    sentence, so long as the defendant acted with even the faintest
    hope that investigators might overlook the document. That
    glimmer of intent is all that the Government would require
    24              UNITED STATES V. KATAKIS
    before subjecting a defendant to felony liability. We cannot
    endorse the Government’s proposed “casual onlooker” test.
    Intent for an item not to be found is inherent in the act of
    concealment. If that intent is satisfied, there is almost no act
    with respect to a document that would not be criminal under
    the Government’s proposed test.
    In this case, we need not set out a comprehensive standard
    for what it means to “conceal” a record under § 1519. Suffice
    to say, contrary to the Government’s position, we cannot
    ignore entirely the effort that an investigator would have to
    expend to uncover a hidden document. In this case, removing
    an email from one file folder and placing it in another was not
    sufficient to actually conceal it. Under the Government’s
    theory, a defendant would have concealed a document even
    by lifting it from the surface of his desk with the intent to
    place it somewhere else, because the defendant would have
    removed the document from where investigators (or not even
    an investigator, a casual onlooker) expected to find it. The
    Government must show actual obstruction. It cannot show
    that here, where it seized all three computers and the email
    server in the course of its investigation and would have
    discovered all single deleted emails within due course.
    Indeed, the Government is in essence arguing that it need not
    undertake any investigation at all: if things are not as the
    Government expects to find them, a defendant may be
    exposed to a term of twenty years’ imprisonment. More is
    needed, there must be some likelihood that the item will not
    be found in the course of a cursory examination (without
    using forensic tools) of a defendant’s computer.
    We emphasize the limited nature of this holding. Our
    conclusion that the evidence was insufficient to convict
    Katakis for single deleting emails rests upon the unique
    UNITED STATES V. KATAKIS                    25
    factual circumstance that pressing the delete key in this
    context serves only to move an email from one file folder to
    another. Section 1519 was drafted to prevent corporate
    document shredding. The digital context threatens to expand
    § 1519 and its potentially harsh punishment well beyond its
    intended reach. We are hesitant to expand the reach of
    § 1519, in part because the Government barely developed the
    facts necessary to support the single-deletion theory at trial
    and we are left without many of the facts that might prove
    actual concealment. As with the other theories raised on
    appeal, the single-deletion theory was an afterthought, a
    comment the Government made at closing and now urges was
    sufficient to warrant a potential twenty-year sentence.
    Accordingly, we cannot endorse the Government’s reading of
    the statute. Actual concealment must do more than merely
    inconvenience a reasonable investigator—there must be some
    likelihood that the item will not be found. That low bar is not
    met in this case.
    CONCLUSION
    Accordingly, we affirm the district court’s order granting
    Katakis a judgment of acquittal. Because we hold that the
    evidence was insufficient to convict Katakis, we do not reach
    his contentions that the Government’s proof created a fatal
    variance with the indictment and that the Government
    committed prosecutorial misconduct.
    AFFIRMED.