Case 12-240, Document 219, 05/27/2016, 1781342, Page1 of 61

12-240-cr (en banc)
United States v. Ganias

UNITED STATES COURT OF APPEALS
FOR THE SECOND CIRCUIT
August Term 2015
(Argued: September 30, 2015

Decided: May 27, 2016)

No. 12-240-cr
––––––––––––––––––––––––––––––––––––
UNITED STATES OF AMERICA,
Appellee,
-v.STAVROS M. GANIAS,
Defendant-Appellant.
––––––––––––––––––––––––––––––––––––
Before: KATZMANN, Chief Circuit Judge, JACOBS, CABRANES, POOLER, RAGGI, WESLEY,
HALL, LIVINGSTON, LYNCH, CHIN, LOHIER, CARNEY, and DRONEY, Circuit Judges.
LIVINGSTON and LYNCH, JJ., filed the majority opinion in which
KATZMANN, C.J., JACOBS, CABRANES, RAGGI, WESLEY, HALL, CARNEY, and
DRONEY, JJ., joined in full, and POOLER and LOHIER, JJ., joined in full as to Parts I
and III and in part as to Part II.
LOHIER, J., filed a concurring opinion in which POOLER, J., joined.
CHIN, J., filed a dissenting opinion.
1

 Case 12-240, Document 219, 05/27/2016, 1781342, Page2 of 61

Appeal from the judgment of the United States District Court for the
District of Connecticut (Thompson, J.), convicting Defendant-Appellant Stavros
Ganias of two counts of tax evasion, in violation of 26 U.S.C. § 7201. Ganias
argues that the Government retained non-responsive data on mirrored hard
drives acquired pursuant to a 2003 search warrant in violation of the Fourth
Amendment, and that evidence acquired pursuant to a 2006 search of that data
should thus have been suppressed. Because we find that the Government relied
in good faith on the 2006 warrant, we need not and do not decide whether the
Government violated the Fourth Amendment, and we affirm the judgment of the
district court.
AFFIRMED.
SANDRA S. GLOVER (Sarala V. Nagala, Anastasia Enos
King, Jonathan N. Francis, Assistant United States
Attorneys; Wendy R. Waldron, Senior Counsel, U.S.
Dep’t of Justice, on the brief), for Deirdre M. Daly,
United States Attorney for the District of Connecticut,
for Appellee United States of America.
STANLEY A. TWARDY, JR., Day Pitney LLP, Stamford,
CT (Daniel E. Wenner, John W. Cerreta, Day Pitney
LLP, Hartford, CT, on the brief), for Defendant-Appellant
Stavros Ganias.
(Counsel for amici curiae are listed in Appendix A.)
DEBRA ANN LIVINGSTON and GERARD E. LYNCH, Circuit Judges:
Defendant-Appellant Stavros Ganias appeals from a judgment of the
United States District Court for the District of Connecticut (Thompson, J.)
convicting him, after a jury trial, of two counts of tax evasion in violation of 26
U.S.C. § 7201. He challenges his conviction on the ground that the Government
2

 Case 12-240, Document 219, 05/27/2016, 1781342, Page3 of 61

violated his Fourth Amendment rights when, after lawfully copying three of his
hard drives for off-site review pursuant to a 2003 search warrant, it retained
these full forensic copies (or “mirrors”), which included data both responsive
and non-responsive to the 2003 warrant, while its investigation continued, and
ultimately searched the non-responsive data pursuant to a second warrant in
2006. Ganias contends that the Government had successfully sorted the data on
the mirrors responsive to the 2003 warrant from the non-responsive data by
January 2005, and that the retention of the mirrors thereafter (and, by extension,
the 2006 search, which would not have been possible but for that retention)
violated the Fourth Amendment. He argues that evidence obtained in executing
the 2006 search warrant should therefore have been suppressed.
We conclude that the Government relied in good faith on the 2006 warrant,
and that this reliance was objectively reasonable. Accordingly, we need not
decide whether retention of the forensic mirrors violated the Fourth
Amendment, and we AFFIRM the judgment of the district court.

3

 Case 12-240, Document 219, 05/27/2016, 1781342, Page4 of 61

I
A. Background 1
In August 2003, agents of the U.S. Army Criminal Investigation Division
(“Army CID”) received an anonymous tip that Industrial Property Management
(“IPM”), a company providing security for and otherwise maintaining a
government-owned property in Stratford, Connecticut, pursuant to an Army
contract, had engaged in misconduct in connection with that work. In particular,
the informant alleged that IPM, owned by James McCarthy, had billed the Army
for work that IPM employees had done for one of McCarthy’s other businesses,
American Boiler, Inc. (“AB”), and for construction work performed for IPM’s
operations manager at his home residence.

The informant told the agents,

including Special Agent Michael Conner, that IPM and AB’s financial books were
maintained by Stavros Ganias, a former Internal Revenue Service (“IRS”) agent,
who conducted business as Taxes International. On the basis of the informant’s
information, as well as extensive additional corroboration, Agent Conner
prepared an affidavit seeking three warrants to search the offices of IPM, AB,

These facts are drawn from the district court decision denying Ganias’s motion
to suppress and from testimony at the suppression hearing and at Ganias’s jury trial.
With few exceptions noted herein, the facts in this case are not in dispute.
1

4

 Case 12-240, Document 219, 05/27/2016, 1781342, Page5 of 61

and Taxes International for evidence of criminal activity. 2 Nothing in the record
suggests that Ganias himself was suspected of any crimes at that time.
In a warrant dated November 17, 2003, U.S. Magistrate Judge William I.
Garfinkel authorized the search of Taxes International. The warrant authorized
agents to seize, inter alia, “[a]ll books, records, documents, materials, computer
hardware and software and computer associated data relating to the business,
financial and accounting operations of [IPM] and [AB].” J.A. 433. It further
authorized seizure of “[a]ny of the items described [in the warrant] . . . which are
stored in the form of magnetic or electronic coding on computer media or on
media capable of being read by a computer with the aid of computer-related
equipment, including . . . fixed hard disks, or removable hard disk cartridges,
software or memory in any form.” Id. The warrant also specifically authorized a
number of digital search protocols, though it did not state that only these

Specifically, Agent Conner sought evidence relating to violations of 18 U.S.C.
§ 287 (making false claims) and § 641 (stealing government property).
2

5

 Case 12-240, Document 219, 05/27/2016, 1781342, Page6 of 61

protocols were permitted. 3 The warrant authorized seizure of all hardware
relevant to the alleged crimes. 4

3

The warrant specified as follows:

The search procedure of the electronic data contained in computer
operating software or memory devices may include the following
techniques:
(a) surveying various file “directories” and the individual files they
contain (analogous to looking at the outside of a file cabinet for the
markings it contains and opening a drawer believed to contain
pertinent files);
(b) “opening” or cursorily reading the first few “pages” of such files in
order to determine their precise contents;
(c) “scanning” storage areas to discover and possibly recover recently
deleted files;
(d) “scanning” storage areas for deliberately hidden files; or
(e) performing key word searches through all electronic storage areas to
determine whether occurrences of language contained in such storage
areas exist that are intimately related to the subject matter of the
investigation.
J.A. 433-34.
In his attached affidavit, Agent Conner offered three reasons why it was
necessary for the agents to take entire hard drives off-site for subsequent search rather
than search the hard drives on-site: First, he stated that computer searches had to be
conducted by computer forensics experts, who “us[ed] . . . investigative techniques” to
both “protect the integrity of the evidence . . . [and] detect hidden, disguised, erased,
compressed, password protected, or encrypted files.” J.A. 448-49. Because of “[t]he
vast array” of software and hardware available, it would not always be possible “to
know before a search which expert is qualified to analyze the [particular] system and its
data.” J.A. 450. Thus, the appropriate experts could not be expected, in all cases, to
accompany agents to the relevant site to be searched. Second, Agent Conner affirmed
that such searches often must occur in “a laboratory or other controlled environment”
given the sensitivity of the digital storage media. J.A. 449-50. And third, he stated that
“[t]he search process can take weeks or months, depending on the particulars of the
hard drive to be searched.” J.A. 449. The district court found, in denying Ganias’s
4

6

 Case 12-240, Document 219, 05/27/2016, 1781342, Page7 of 61

On November 19, 2003, Army CID agents executed the search warrants.
Because the warrants authorized the seizure of computer hardware and
software, in addition to paper documents, Agent Conner sought the help, in
executing the warrants, of agents from the Army CID’s Computer Crimes
Investigation Unit (“CCIU”), a unit with specialized expertise in digital forensics
and imaging. At Ganias’s office, the CCIU agents — and in particular Special
Agent David Shaver — located three computers. Rather than take the physical
hard drives, which would have significantly impaired Ganias’s ability to conduct
his business, Agent Shaver created mirror images: exact copies of all of the data
stored thereon, down to the bit. 5 Ganias was present at his office during the
creation of the mirrors, spoke with the agents, and was aware that mirrored

motion to suppress, that, as a result of technological limitations in 2003 and the
complexities of searching digital data, “[a] full [on-site] search would have taken
months to complete.” United States v. Ganias, No. 3:08CR00224 (AWT), 2011 WL
2532396, at *2 (D. Conn. June 24, 2011).
Hard drives are storage media comprising numerous bits — units of data that
may be expressed as ones or zeros. Mirroring involves using a commercially available
digital software (in the present case, though not always, EnCase) to obtain a perfect,
forensic replica of the sequence of ones and zeros written onto the original hard drive.
During the mirroring, EnCase acquires metadata about the mirroring process, writing
an unalterable record of who creates the copy and when the copy is created. It also
assigns the mirror a “hash value” — a unique code that can be used to verify whether,
upon subsequent examination of the mirror at any later date, even a single one or zero
has been altered from the original reproduction.
5

7

 Case 12-240, Document 219, 05/27/2016, 1781342, Page8 of 61

copies of his three hard drives had been created and taken off-site. 6 There is no
dispute that the forensic mirrors taken from Ganias’s office contained all of the
computerized data maintained by Ganias’s business, including not only material
related to IPM or AB, but also Ganias’s own personal financial records, and the
records of “many other” accounting clients of Ganias: businesses of various sorts
having no connection to the Government’s criminal investigation. 7 J.A. 464, ¶ 14.

Testifying at the suppression hearing, Agent Conner explained that the decision
to take mirrors, rather than the hard drives themselves, reflected a desire to mitigate the
burden on Ganias and his business. See J.A. 140-41. The district court credited this
testimony, concluding that the agents “used a means less intrusive to the individual
whose possessions were seized than other means they were authorized to use.” Ganias,
2011 WL 2532396, at *8. The district court, further, explicitly found that the 2003
warrant authorized the Government to take these mirrors, id. at *10, a position Ganias
has not challenged on appeal, and that runs directly counter to the dissent’s seeming
suggestions that the Government somehow acted improperly when it mirrored Ganias’s
hard drives or that this initial seizure went beyond the scope of the 2003 warrant, see,
e.g., Dissent at 3 (noting that “although the Government had a warrant for documents
relating to only two of defendant-appellant Stavros Ganias’s accounting clients, it
seized all the data from three of his computers”); id. at 40 (stating that “the
6

Government . . . entered Ganias’s premises with a warrant to seize certain papers and
indiscriminately seized — and retained — all papers instead”).

Ganias claimed before the district court that when he expressed some concern
about the scope of the data being seized, an agent assured him that the agents were only
looking for files related to AB and IPM, and that irrelevant files “would be purged once
they completed their search” for such files. J.A. 428. The district court made no finding
to this effect, however. It is undisputed, moreover, that Ganias became aware in
February 2006 that the Government retained the mirrors and sought to search them in
connection with Ganias’s own tax reporting. At no time thereafter did Ganias seek
return of the mirrors pursuant to Federal Rule of Criminal Procedure 41(g) or otherwise
contact a case agent to seek their return or destruction.
7

8

 Case 12-240, Document 219, 05/27/2016, 1781342, Page9 of 61

The next day, Agent Shaver consolidated the eleven mirrored hard drives
from all three searches (including the three from Ganias’s office) onto a single
external hard drive which he provided to Agent Conner. Agent Conner, in turn,
provided this hard drive to the evidence custodian of the Army CID, who stored
it at Fort Devens, Massachusetts.

There the consolidated drive remained,

unaltered and untouched, throughout the events relevant to this case. Around
the same time, Agent Shaver created two additional copies of the mirrored drives
on two sets of nineteen DVDs. After providing these DVD sets to Agent Conner,
Agent Shaver then purged the external hard drives onto which he had originally
written the mirrors. At this point, a week after the search, three complete copies
of the mirrors of Ganias’s hard drives existed: an untouched copy stowed away
in an evidence locker and two copies available for forensic analysis. 8
Though internal protocols required that specialized digital forensic
analysts search the mirrored hard drives, the paper files were not subject to such
limitations. Thus, shortly after the November 19 seizure, the Army CID agents

These copies were identical digital replicas of Ganias’s hard drives as mirrored
on November 19, 2003. Notably, the original hard drives in Ganias’s computers had
already been significantly altered since the Government mirrored them. Ganias
explains in his brief before this Court that “[t]wo days after the execution of the
November 2003 warrant, [he] reviewed his personal QuickBooks file and . . . . corrected
over 90 errors in earlier journal entries.” Appellant Br. at 15 n.7 (emphasis added).
8

9

 Case 12-240, Document 219, 05/27/2016, 1781342, Page10 of 61

began to analyze the non-digital files seized pursuant to the warrant. These files
suggested that IPM had made payments to a third company whose owner,
according to the Connecticut Department of Labor, was a full-time employee of
an insurance company who received no wages from any source other than that
insurance company. This and other red flags spurred Agent Conner to contact
the Criminal Investigation Division of the IRS, which subsequently joined the
investigation.
In early February 2004, as he and his fellow agents continued to follow
leads from the paper files, Agent Conner sent one of the two DVD sets
containing the forensic mirrors to the Army Criminal Investigation Laboratory
(“ACIL”) in Forest Park, Georgia, accompanied by a copy of one of the three
search warrants. In early June, the ACIL assigned Gregory Norman, a digital
evidence examiner, to perform a forensic analysis.

Around the same time,

Special Agent Michelle Chowaniec, who replaced Agent Conner as the primary
case agent for the Army CID in late March, provided the second set of DVDs to
the IRS agent assigned to the case, Special Agent Paul Holowczyk.

Agent

Holowczyk in turn, passed it on, by way of intermediaries, to Special Agent Vita
Paukstelis, a computer investigative specialist.

10

By the end of June 2004,

 Case 12-240, Document 219, 05/27/2016, 1781342, Page11 of 61

computer experts for the Army CID and the IRS — Norman and Agent
Paukstelis, respectively — had received copies of the digital evidence (which, as
the district court found, were “encoded so that only agents with forensic
software not directly available to the case agents could view [them],” Ganias,
2011 WL 2532396, at *7), and forensic examination began.
Norman commenced his analysis in late June by loading the eleven
mirrored drives into EnCase — the same software with which Agent Shaver
initially created the mirrors — so that he could search the data thereon. After
looking at the search warrants, he created a number of keywords, with which he
searched for potentially relevant data. Initially, the search returned far too many
results for practicable review (more than 17,000 hits); thus, Norman requested
new keywords from Agent Chowaniec. On the basis of these new keywords, he
was able to narrow his search and ultimately identify several files he thought
might be of interest to the investigation, all of which he put on a single CD. 9
Some of these files he was able personally to examine, to determine whether they
were responsive to the warrant; a few (including the QuickBooks file labeled

The rest of the data remained on the DVDs, where agents would not be able to
access it without specific forensic software. See Ganias, 2011 WL 2532396, at *7.
9

11

 Case 12-240, Document 219, 05/27/2016, 1781342, Page12 of 61

“Steve_ga.qbw,” which was ultimately searched pursuant to the 2006 warrant,
J.A. 467) Norman could not open without a specific software edition of
QuickBooks to which he did not have immediate access. However, as these files
(like the others) contained keywords that were taken from the narrower list and
generated on the basis of the warrant, Norman included the QuickBooks files in
the CD he ultimately sent to Agent Chowaniec along with a report. 10 On July 23,
2004, Chowaniec received this CD.

Norman, in turn, returned the nineteen

DVDs to Army CID’s evidence custodian in Boston for safekeeping.
Norman’s counterpart in the IRS, Agent Paukstelis — who, in addition to
receiving the search warrant with her set of DVDs, also received a list of
companies, addresses, and key individuals relating to the investigation, along
with “a handwritten notation next to the name ‘Taxes International’ that stated
‘(return preparer) do not search,’” Ganias, 2011 WL 2532396, at *3 — conducted
her analysis over a period of about four months. Because she worked for the IRS,
she limited her search to the three mirrored drives from Taxes International.
Though Agent Paukstelis used ILook, a different software program, to review
the mirrored hard drives, she too could not open QuickBooks files without the
Norman describes the storage device he sent to Chowaniec as a “DVD,”
J.A. 218; the district court described it as a “CD,” Ganias, 2011 WL 2532396, at *4. The
distinction is immaterial.
10

12

 Case 12-240, Document 219, 05/27/2016, 1781342, Page13 of 61

relevant proprietary software. Still, though she could not open these files, she
believed, based on the information to which she had access, that they were
within the scope of the warrant; thus, in October 2004, she copied this data, in
concert with other responsive data, onto a CD, three copies of which she sent to
Agent Holowczyk and Special Agent Amy Hosney, also with the IRS. In light of
the note she had received with her DVD set as well as the list of relevant entities,
Agent Paukstelis avoided, to the degree she could, searching any files of Taxes
International that did not appear to be directly relevant to that list.

On

November 30, 2004, Paukstelis also provided a “restoration” of the mirrors of the
Taxes International hard drives to Special Agent George Francischelli, an IRS
computer specialist assigned to the case. 11
Agents Chowaniec and Conner, after receiving Norman’s CD and report in
late July, conducted initial reviews of the data.

Like Norman and Agent

Paukstelis, however, they could not open the QuickBooks files. At the same
time, the agents were busy, in the words of Agent Chowaniec, “tracking down
other leads[,] . . . [issuing] grand jury subpoenas, . . . doing interviews of

A “restoration” is a software interface that enables a user (potentially a jury) to
view data on a mirror as such data would have appeared to a person accessing the data
on the original storage device at the time the mirror was created. Ganias, 2011 WL
2532396, at *4.
11

13

 Case 12-240, Document 219, 05/27/2016, 1781342, Page14 of 61

subcontractors and identifying subcontractors from the papers that [the agents
had] received from the search warrants.”

J.A. 294-95.

In October, Agents

Hosney and Chowaniec attempted, together, to review the QuickBooks files, but
again lacked the relevant software to do so. Finally, in November 2004, Agent
Chowaniec, having acquired the appropriate software, opened two IPM
QuickBooks files on her office computer, and then in December, Agents Hosney
and Chowaniec, using the restoration provided by Agent Paukstelis, looked at
additional IPM QuickBooks files. Though they had the entirety of the mirrored
data before them (the only time throughout the investigation that the case agents
had direct access to a software interface permitting them to view essentially all of
the data stored on the mirrors), they carefully limited their search: Agent Hosney
testified that they “only looked at the QuickBooks files for Industrial Property
Management and American Boiler . . . [b]ecause those were the only two
companies named in the search warrant attachment.”

J.A. 340.

They did,

however, observe that other files existed — both on the CD Norman had
provided and on the restoration — in particular, the files Agent Hosney
ultimately searched in 2006.

14

 Case 12-240, Document 219, 05/27/2016, 1781342, Page15 of 61

Ganias contends that there is no dispute that by this point, the agents had
finished “identifying and segregating the files within the November 2003
warrant’s scope.” Appellant Reply Br. at 5. In actuality, the record is unclear as
to whether the forensic examination of the mirrored computers pursuant to the
initial search warrant had indeed concluded as a forward-looking matter, rather
than from the perspective of hindsight. 12 The district court did not find any facts
decisive to this question. It is, further, undisputed that the investigation into
McCarthy, IPM, and AB was ongoing at this time, and that this investigation
would culminate in an indictment of McCarthy in 2008 secured in large part
through reliance on evidence responsive to the 2003 warrant and located on the
mirrored copies of Ganias’s hard drives. See Indictment, United States v. McCarthy,
At the suppression hearing, Agent Chowaniec testified, in response to the
question whether “as of mid-December, [her] forensic analysis was completed”: “That’s
correct, of the computers.” J.A. 322. But when asked later, “[D]id you know [in
December 2004] you wouldn’t need to look at any information that had been provided
by Greg Norman on that CD anymore in the course of this investigation,” Agent
Chowaniec responded, “No,” and when further asked, “Did you know you wouldn’t
require further analysis by Greg Norman or any other examiner at the Army lab in
Georgia after December of 2004,” Agent Chowaniec again responded, “No.” J.A. 324.
Agent Conner similarly answered with uncertainty when asked a related question. See
J.A. 145 (“I didn’t know the entire universe of information that was contained within
the DVDs that were sent to [Norman] for analysis. I knew only what he sent back to me
saying this is what I found off your keyword search.”). The dissent disputes our
conclusion that the record was unclear on this point, arguing, through citation to Agent
Chowaniec’s testimony, that “the record . . . shows otherwise.” Dissent at 19. The
district court found no facts on this issue, and the record, as demonstrated above, is
indeed unclear.
12

15

 Case 12-240, Document 219, 05/27/2016, 1781342, Page16 of 61

No. 3:08cr224 (EBB) (D. Conn. Oct. 31, 2008), ECF No. 1. When asked why, at this

time or any time later, Agent Conner did not return or destroy the data stored on
the mirrors that did not appear directly to relate to the crimes alleged in the
warrant, Agent Conner explained that “[the] investigation was still . . . open” and
that, generally, items would be “released back to the owner” once an
investigation was closed. J.A. 123. He further noted that the Army CID “would
not routinely go into DVDs to delete data, as we’re altering the original data that
was seized.” J.A. 122. 13
Over the next year, the agents continued to investigate IPM and AB.
Analysis of the paper files taken pursuant to the November 2003 search warrant

Agent Conner’s explanation for why the Government did not, as a matter of
policy in this or other cases, delete mirrored drives or otherwise require segregation or
deletion of non-responsive data, is not a model of clarity: in addition to citing concerns
of evidentiary integrity and suggesting a policy of non-deletion or return prior to the
end of an investigation, he noted that “you never know what data you may need in the
future,” J.A. 122, and at one point referred to the DVDs as “the government’s property,
not Mr. Ganias’[s] property,” J.A. 146. The dissent seizes on this single sentence during
Agent Conner’s cross-examination as the smoking gun of the Government’s bad faith,
citing it on no fewer than four occasions. See Dissent at 3, 8, 33, 37. The district court,
however, did not find facts explicating Agent Conner’s testimony or placing it within
the context of the explanations that he and other agents offered for retention of the
mirrors. The court did note in its legal analysis that “[a] copy of the evidence was
preserved in the form in which it was taken.” Ganias, 2011 WL 2532396, at *8. Further,
the Government on appeal provides numerous rationales — many echoing those
articulated by Agent Conner throughout his testimony — for why retention of a forensic
mirror may be necessary during the pendency of an investigation, none of which
amounts to the argument that the mirror is simply “government[] property.”
13

16

 Case 12-240, Document 219, 05/27/2016, 1781342, Page17 of 61

revealed potential errors in AB’s tax returns that seemed to omit income reflected
in checks deposited into IPM’s account. Aware that Ganias had prepared these
tax returns and deposited the majority of these checks, Agent Hosney came to
suspect that Ganias was engaged in tax-related crimes. 14 She did not, however,
return to the restoration or otherwise open any of Ganias’s digital financial
documents or files associated with Taxes International. 15 Instead, Agent Hosney
subpoenaed Ganias’s bank records from 1999 to 2003 and accessed his income
The dissent suggests that “[w]hat began nearly thirteen years ago as an
investigation by the Army into two of Ganias’s business clients somehow evolved into an
unrelated investigation by the IRS into Ganias’s personal affairs, largely because” the
Government retained the mirrored copies of Ganias’s hard drives. Dissent at 40
(emphasis added). In fact, Agent Hosney’s affidavit in support of the 2006 warrant
explains that the Government suspected Ganias of underreporting his income because
of evidence that Ganias had assisted McCarthy in underreporting income from
McCarthy’s companies — evidence which led to an indictment of both McCarthy and
Ganias for conspiracy to commit tax fraud. Further, when Agent Hosney developed
this suspicion — which was hardly “unrelated” to the initial investigation — she did
not turn to the mirrors, but instead engaged in old-fashioned investigatory work,
“examin[ing Ganias’s tax returns] more closely to determine if his own income was
underreported.” J.A. 465, ¶ 18. She then reviewed deposits in his bank account, crossreferenced bank records and tax returns, and finally presented this evidence in a proffer
session to Ganias — all without once looking at any non-responsive information on the
mirrors. Only after she had acquired independent probable cause — and only after
extensive evidence suggested Ganias may have committed a crime — did Agent
Hosney seek a second warrant to search the mirrors. It is, in short, no mystery how the
investigation of McCarthy, IPM, and AB came to include Ganias, and, further, an
inaccurate statement of the record to suggest that this “evolution” had anything to do
with the retention of the mirrors.
14

Agent Hosney explained in her testimony: “[W]e couldn’t look at that file
because it wasn’t — Steve Ganias and Taxes International were not listed on the original
Attachment B, items to be seized.” J.A. 348.
15

17

 Case 12-240, Document 219, 05/27/2016, 1781342, Page18 of 61

tax returns for the same period. On July 28, 2005, the IRS — believing Ganias to
be involved both personally and as an accomplice or co-conspirator in tax
evasion — officially expanded the investigation to include him.
On February 14, 2006, Ganias, accompanied by his lawyer, met in a proffer
session with Agent Hosney and others involved in the investigation. 16 That day
or shortly thereafter, Agent Hosney asked Ganias for consent to access his
personal QuickBooks files and those of his business, Taxes International — data
Agent Hosney knew to be present on the forensic mirrors but which she had not
accessed. When, by April 24, 2006 (two and a half months later), Ganias had
failed to respond (either by consenting, objecting, or filing a motion under
Federal Rule of Criminal Procedure 41(g) for return of seized property), Agent
Hosney sought a search warrant to search the mirrored drives again. 17 In her
search warrant affidavit, Agent Hosney pointed to bank records, income tax
forms, and additional evidence to demonstrate that she had probable cause to
According to Agent Hosney, in that proffer session Ganias claimed “that he
failed to record income from his own business [to his QuickBook files] as a result of a
computer flaw in the QuickBooks software . . . [but that,] . . . although he attempted to
duplicate the software error, he was unable to do so.” J.A. 467, ¶ 28. Agent Hosney
contacted Intuit, Inc., which released QuickBooks, to determine whether such an error
might have affected, generally, the pertinent version of the software, and was told that
the company was aware of no such “widespread malfunction.” J.A. 469, ¶ 35.
16

U.S. Magistrate Judge William I. Garfinkel, who had authorized the 2003
warrant, authorized this 2006 warrant as well. J.A. 430, 454.
17

18

 Case 12-240, Document 219, 05/27/2016, 1781342, Page19 of 61

believe that Ganias had violated 26 U.S.C. § 7201 (by committing tax evasion)
and § 7206(1) (by making false declarations). 18 She further noted that the items to
be searched were “mirror images of computers seized on November 19, 2003
from the offices of Taxes International,” J.A. 461, ¶ 7; that information material to
the initial investigation had been located on these mirrors and that, “[d]uring
th[at] investigation,” such information had been “analyzed in detail,” J.A. 464,
¶ 15; that Ganias was not, at the time of the initial seizure, under investigation,
J.A. 461, ¶ 3 (“On July 28, 2005, the Government’s investigation was expanded to
include an examination of whether Ganias, McCarthy’s accountant and former
IRS Revenue Agent, violated the federal tax laws.”); and thus that, though Agent
Hosney believed that the second mirrored drive, called TaxInt_2, was “the
primary computer for Taxes International,” J.A. 463, ¶ 13, she could not search
Ganias’s personal or business files as “[p]ursuant to the 2003 search warrant,
only files for [AB] and IPM could be viewed,” J.A. 464, ¶ 14. The magistrate
judge issued the warrant, Agent Hosney searched the referenced data, and
ultimately the Government indicted Ganias for tax evasion.

Ganias did not contest before the district court, and does not contest on appeal,
that this evidence — none of which was acquired through search of non-responsive
data on the mirrors — created sufficient probable cause for the 2006 warrant.
18

19

 Case 12-240, Document 219, 05/27/2016, 1781342, Page20 of 61

B. Procedural History
In February 2010, Ganias moved to suppress the evidence Agent Hosney
acquired pursuant to the 2006 warrant. After a two-day hearing, the district
court denied the motion on April 14, 2010, and issued a written decision on June
24, 2011. In that decision, the district court found, inter alia, that the forensic
examination of the mirrored drives “was conducted within the limitations
imposed by the [2003] warrant” and that “[a] copy of the evidence was preserved
in the form in which it was taken.” Ganias, 2011 WL 2532396, at *8. Judge
Thompson observed that Ganias “never moved for destruction or return of the
data, which could have led to the seized pertinent data being preserved by other
means.” Id. The district court concluded that the Government’s retention of the
mirrored drives — and thus its subsequent search of those drives pursuant to a
warrant — did not violate the Fourth Amendment. Having found no Fourth
Amendment violation, the district court did not reach the question of good faith.
Id. at *9.
At trial, the Government introduced information in Ganias’s QuickBooks
files as evidence against him, in particular highlighting the fact that payments
made to him by clients such as IPM were characterized as “owner’s

20

 Case 12-240, Document 219, 05/27/2016, 1781342, Page21 of 61

contributions,” which prevented QuickBooks from recognizing them as income.19
On the basis of this and other evidence, the jury convicted Ganias of two counts
of tax evasion, and the district court sentenced him to two terms of 24 months’
incarceration, to be served concurrently.
Ganias appealed.

On review of his conviction, a panel of this Court

concluded, unanimously, that the Government had violated the Fourth
Amendment; in a divided decision, the panel then ordered suppression of the
evidence obtained in executing the 2006 warrant and vacated the jury verdict.
We subsequently ordered this rehearing en banc in regards to, first, the existence
of a Fourth Amendment violation and, second, the appropriateness of
suppression. 20

Many of these entries existed only on the QuickBooks files that the Government
had accessed on the mirrors, as a result of Ganias’s amendments to the entries on his
hard drives days after the execution of the 2003 warrant. At trial, Ganias testified that
his characterization of the payments as “owner’s contributions” was simply a good faith
mistake, and not evidence of intent to commit tax evasion, a claim that the Government
labeled implausible in light of Ganias’s extensive experience as an IRS agent and
accountant.
19

20

Specifically, we asked the parties to brief the following two issues:

(1) Whether the Fourth Amendment was violated when, pursuant to a
warrant, the government seized and cloned three computer hard drives
containing both responsive and non-responsive files, retained the cloned
hard drives for some two-and-a-half years, and then searched the nonresponsive files pursuant to a subsequently issued warrant; and

21

 Case 12-240, Document 219, 05/27/2016, 1781342, Page22 of 61

II
“On appeal from a district court’s ruling on a motion to suppress evidence,
‘we review legal conclusions de novo and findings of fact for clear error.’”
United States v. Bershchansky, 788 F.3d 102, 108 (2d Cir. 2015) (quoting United
States v. Freeman, 735 F.3d 92, 95 (2d Cir. 2013)). We may uphold the validity of a
judgment “on any ground that finds support in the record.” Headley v. Tilghman,
53 F.3d 472, 476 (2d Cir. 1995).
The district court concluded that the conduct of the agents in this case
comported fully with the Fourth Amendment, and thus did not reach the
question whether they also acted in good faith. Because we conclude that the
agents acted in good faith, we need not decide whether a Fourth Amendment
violation occurred. We thus affirm the district court on an alternate ground.
Nevertheless, though we offer no opinion on the existence of a Fourth
Amendment violation in this case, we make some observations bearing on the
reasonableness of the agents’ actions, both to illustrate the complexity of the
questions in this significant Fourth Amendment context and to highlight the
(2) Considering all relevant factors, whether the government agents in this
case acted reasonably and in good faith such that the files obtained from
the cloned hard drives should not be suppressed.

United States v. Ganias, 791 F.3d 290 (2d Cir. 2015) (mem.).
22

 Case 12-240, Document 219, 05/27/2016, 1781342, Page23 of 61

importance of careful consideration of the technological contours of digital
search and seizure for future cases.
“The touchstone of the Fourth Amendment is reasonableness . . . .” United
States v. Miller, 430 F.3d 93, 97 (2d Cir. 2005) (alteration omitted) (quoting United
States v. Knights, 534 U.S. 112, 118 (2001)). As relevant here, “searches pursuant
to a warrant will rarely require any deep inquiry into reasonableness.” United
States v. Leon, 468 U.S. 897, 922 (1984) (alteration omitted) (quoting Illinois v.
Gates, 462 U.S. 213, 267 (1983) (White, J., concurring in judgment)). Nevertheless,
both the scope of a seizure permitted by a warrant, 21 and the reasonableness of

Specifically, courts have long recognized that a prohibition on “general
warrants” — warrants completely lacking in particularity — was a central impetus for
the ratification of the Fourth Amendment. See, e.g., Riley v. California, 134 S. Ct. 2473,
2494 (2014) (noting, in the context of evaluating the reasonableness of a warrantless
search of a cell phone, that “[o]ur cases have recognized that the Fourth Amendment
was the founding generation’s response to the reviled ‘general warrants’ and ‘writs of
assistance’ of the colonial era, which allowed British officers to rummage through
homes in an unrestrained search for evidence of criminal activity” and that “opposition
to such searches was in fact one of the driving forces behind the Revolution itself”);
Marshall v. Barlow’s, Inc., 436 U.S. 307, 311 (1978) (noting, in the context of evaluating the
reasonableness of warrantless inspections of business premises, that “[t]he particular
offensiveness” of general warrants “was acutely felt by the merchants and businessmen
whose premises and products were inspected” under them); Stanford v. Texas, 379 U.S.
476, 486 (1965) (“[T]he Fourth . . . Amendment[] guarantee[s] . . . that no official . . . shall
ransack [a person’s] home and seize his books and papers under the unbridled
authority of a general warrant . . . .”); United States v. Galpin, 720 F.3d 436, 445 (2d Cir.
2013) (“The chief evil that prompted the framing and adoption of the Fourth
Amendment was the ‘indiscriminate searches and seizures’ conducted by the British
21

23

 Case 12-240, Document 219, 05/27/2016, 1781342, Page24 of 61

government conduct in executing a valid warrant,

22

can present Fourth

Amendment issues. Ganias thus argues that the Government violated the Fourth
Amendment in this case, notwithstanding the two warrants that issued, by
retaining complete forensic copies of his three hard drives during the pendency
of its investigation.
According to Ganias, when law enforcement officers execute a warrant for
a hard drive or forensic mirror that contains data that, as here, cannot feasibly be
‘under the authority of “general warrants.”’” (quoting Payton v. New York, 445 U.S. 573,
583 (1980))).
We agree with the dissent that “the precedents are absolutely clear that general
warrants are unconstitutional.” Dissent at 30. To the degree that the dissent would go
further, however, and find it “absolutely clear” to a reasonable government agent in
2005 that the retention of a lawfully acquired mirror during the pendency of an
investigation and the subsequent search of data on that mirror pursuant to a second
warrant would implicate the ban on general warrants, we respectfully disagree.
See, e.g., L.A. Cty. v. Rettele, 550 U.S. 609, 614-16 (2007) (applying the
reasonableness standard to evaluate whether police officers’ manner of executing a
valid warrant violated the Fourth Amendment); Wilson v. Layne, 526 U.S. 603, 611 (1999)
(“[T]he Fourth Amendment does require that police actions in execution of a warrant be
related to the objectives of the authorized intrusion . . . .”); Dalia v. United States, 441 U.S.
238, 258 (1979) (“[T]he manner in which a warrant is executed is subject to later judicial
review as to its reasonableness.”); Terebesi v. Torreso, 764 F.3d 217, 235 (2d Cir. 2014)
(“[T]he method used to execute a search warrant . . . [is] as a matter of clearly
established constitutional law, subject to Fourth Amendment protections . . . .”), cert.
denied sub nom. Torresso v. Terebesi, 135 S. Ct. 1842 (2015) (mem.); Lauro v. Charles, 219
F.3d 202, 209 (2d Cir. 2000) (“[T]he Fourth Amendment’s proscription of unreasonable
searches and seizures ‘not only . . . prevent[s] searches and seizures that would be
unreasonable if conducted at all, but also . . . ensure[s] reasonableness in the manner
and scope of searches and seizures that are carried out.’” (all but first alteration in
original) (quoting Ayeni v. Mottola, 35 F.3d 680, 684 (2d Cir. 1994))).
22

24

 Case 12-240, Document 219, 05/27/2016, 1781342, Page25 of 61

sorted into responsive and non-responsive categories on-site, “the Fourth
Amendment demands, at the very least, that the officers expeditiously complete
their off-site search and then promptly return (or destroy) files outside the
warrant’s scope.” 23 Appellant Br. at 18. Arguing that a culling process took
place here and that it had concluded by, at the latest, January 2005, Ganias faults
the Government for retaining the mirrored drives — including storing one

On appeal, Ganias does not question the scope or validity of the 2003 warrant.
The district court found that the 2003 warrant authorized the Government to mirror
Ganias’s hard drives for off-site review, Ganias, 2011 WL 2532396, at *10; that the
warrant, though authorizing such seizure, was sufficiently particularized and not a
“general warrant,” id.; that, absent mirroring for off-site review, on-site review would
have taken months, id. at *2; and that mirroring thus minimized any intrusion on
Ganias’s business, id. at *8; cf. Fed. R. Crim. P. 41(e)(2)(B) (which, as amended in 2009,
permits a warrant to “authorize the seizure of electronic storage media or the seizure or
copying of electronically stored information,” and notes that “[u]nless otherwise
specified, the warrant authorizes a later review of the media or information consistent
with the warrant”); Fed. R. Crim. P. 41(e)(2)(B) advisory committee’s note to 2009
amendments (explaining that, because “[c]omputers and other electronic storage media
commonly contain such large amounts of information that it is often impractical for law
enforcement to review all of the information during execution of the warrant at the
search location[, t]his rule acknowledges the need for a two-step process:  officers may
seize or copy the entire storage medium and review it later to determine what
electronically stored information falls within the scope of the warrant”). Ganias does
not contest these conclusions on appeal but contends, instead, that considerations
underlying the prohibition on general warrants may require that, if the government
lawfully mirrors an entire hard drive containing non-responsive as well as responsive
information for off-site review, it may not then retain the mirror throughout the
pendency of its investigation.
23

25

 Case 12-240, Document 219, 05/27/2016, 1781342, Page26 of 61

forensic copy in an evidence locker for safekeeping. 24 It was this retention, he
argues, that constituted the Fourth Amendment violation — a violation that, in
turn, made the 2006 search of the data itself unconstitutional as, but for this
retention, the search could never have occurred.
To support this argument, Ganias relies principally on United States v.
Tamura, 694 F.2d 591 (9th Cir. 1982), a Ninth Circuit case involving the search
and seizure of physical records. In Tamura (unlike the present case, in which a
warrant specifically authorized the agents to seize hard drives and to search
them off-site) officers armed only with a warrant authorizing them to seize
specific “records” instead seized numerous boxes of printouts, file drawers, and
cancelled checks for off-site search and sorting. Id. at 594-95. After the officers
had clearly sorted the responsive paper documents from the non-responsive
ones, they refused — despite request — to return the non-responsive paper files.
Id. at 596-97. The Ninth Circuit concluded that both the unauthorized seizure of
voluminous material not specified in the warrant and the retention of the seized

As already noted, the district court made no finding as to when or whether
forensic examination of the mirrors pursuant to the 2003 warrant was completed.
24

26

 Case 12-240, Document 219, 05/27/2016, 1781342, Page27 of 61

documents violated the Fourth Amendment. 25 Id. at 595, 597; see also Andresen v.
Maryland, 427 U.S. 463, 482 n.11 (1976) (“[W]e observe that to the extent [seized]
papers were not within the scope of the warrants or were otherwise improperly
seized, the State was correct in returning them voluntarily and the trial judge
was correct in suppressing others. . . . In searches for papers, it is certain that
some innocuous documents will be examined, at least cursorily, in order to
determine whether they are, in fact, among those papers authorized to be
seized. . . . [R]esponsible officials [conducting such searches], including judicial
officials, must take care to assure that they are conducted in a manner that
minimizes unwarranted intrusions upon privacy.”); cf. United States v. Matias, 836
F.2d 744, 747 (2d Cir. 1988) (“[W]hen items outside the scope of a valid warrant
are seized, the normal remedy is suppression and return of those items . . . .”).
Because we resolve this case on good faith grounds, we need not decide
the relevance, if any, of Tamura (or, more broadly, the validity of Ganias’s Fourth
Amendment claim). We note, however, that there are reasons to doubt whether
Tamura (to the extent we would indeed follow it) answers the questions before
us. First, on its facts, Tamura is distinguishable from this case, insofar as the
The Ninth Circuit declined to reverse the defendant’s conviction, as no
improperly seized document was admitted at trial, and as blanket suppression was not
warranted. See Tamura, 694 F.2d at 597.
25

27

 Case 12-240, Document 219, 05/27/2016, 1781342, Page28 of 61

officers there seized for off-site review records that the warrant did not authorize
them to seize, 26 and retained those records even after their return was requested.
Here, in contrast, the warrant authorized the seizure of the hard drives, not
merely particular records, and Ganias did not request return or destruction of the
mirrors (even after he was indisputably alerted to the Government’s continued
retention of them) by, for instance, filing a motion for such return pursuant to
Federal Rule of Criminal Procedure 41(g). Second, and more broadly, even if the
facts of Tamura were otherwise on point, Ganias’s invocation of Tamura’s
reasoning rests on an analogy between paper files intermingled in a file cabinet
and digital data on a hard drive. Though we do not take any position on the
ultimate disposition of the constitutional questions herein, we nevertheless pause
to address the appropriateness of this analogy, which is often invoked (including
by the dissent) and bears examination.
The central premise of Ganias’s reliance on Tamura is that the search of a
digital storage medium is analogous to the search of a file cabinet. The analogy
has some force, particularly as seen from the perspective of the affected
The fact that the officers in Tamura lacked a warrant for the initial seizure was
not incidental to the decision: the Tamura court explicitly found that it was the lack of a
warrant that made the initial seizure — even if otherwise understandable in light of the
voluminous material to be reviewed — a violation of the Fourth Amendment. See 694
F.2d at 596.
26

28

 Case 12-240, Document 219, 05/27/2016, 1781342, Page29 of 61

computer user. Computer users — or at least, average users (in contrast to, say,
digital forensics experts) — typically experience computers as filing cabinets, as
that is precisely how user interfaces are designed to be perceived by such users. 27
Given that the file cabinet analogy (at least largely) thus captures an average
person’s subjective experience with a computer interface, the analogy may shed
light on a user’s subjective expectations of privacy regarding data maintained on
a digital storage device. Because we experience digital files as discrete items, and
because we navigate through a computer as through a virtual storage space, we
may expect the law similarly to treat data on a storage device as comprised of
distinct, severable files, even if, in fact, “[s]torage media do not naturally divide
into parts.” Josh Goldfoot, The Physical Computer and the Fourth Amendment, 16
Berkeley J. Crim. L. 112, 131 (2011).

In this case, for example, a person in

See Daniel B. Garrie & Francis M. Allegra, Fed. Judicial Ctr., Understanding
Software, the Internet, Mobile Computing, and the Cloud: A Guide for Judges 8-14 (2015)
(contrasting “operating systems . . . [which] hide the hardware resources behind
abstractions to provide an environment that is more user-friendly,” id. at 13, with
machine language, assembly language, high-level languages, data structures, and
algorithms); Josh Goldfoot, The Physical Computer and the Fourth Amendment, 16 Berkeley
J. Crim. L. 112, 117 (2011) (contrasting two perspectives on digital storage media — the
“internal perspective,” or how “the user experiences [such media,] as parcels of
information, grouped into files, or even into smaller units such as spreadsheet rows”
and the “external perspective,” or how the actual computer functions, in which “files
are not . . . ‘things’ at all,” but “groupings of data . . . inseparably tied to the storage
medium,” created by the computer by manipulating “chunks of physical matter [such
as regions on a hard drive] whose state is altered to record information”).
27

29

 Case 12-240, Document 219, 05/27/2016, 1781342, Page30 of 61

Ganias’s situation could well understand the “files” on his hard drives
containing information relating to IPM and AB as separate from the “files”
containing his personal financial information and that of other clients. Indeed,
the very fact that the Government sought additional search authorization via the
2006 warrant when it established probable cause to search Ganias’s personal files
indicates that the Government too understood — and credited — this distinction.
That said, though it may have some relevance to our inquiry, the file
cabinet analogy is only that — an analogy, and an imperfect one. Cf. James
Boyle, The Public Domain 107 (2008) (“Analogies are only bad when they ignore
the key difference between the two things being analyzed.”). Though to a user a
hard drive may seem like a file cabinet, a digital forensics expert reasonably
perceives the hard drive simply as a coherent physical storage medium for
digital data — data that is interspersed throughout the medium, which itself must
be maintained and accessed with care, lest this data be altered or destroyed. 28 See

See Eoghan Casey, Digital Evidence and Computer Crime 472, 474-96 (3d ed. 2011)
(highlighting the fact that forensic examination of storage media can create tiny
alterations, which necessitates care on the part of examiners in acquiring, searching, and
preserving that data); id. at 477-78 (describing the importance of protecting digital
storage media from “dirt, fluids, humidity, impact, excessive heat and cold, strong
magnetic fields, and static electricity”); Michael W. Graves, Digital Archaeology: The Art
and Science of Digital Forensics 95 (2014) (“Computer data is extremely volatile and easily
deleted, and can be destroyed, either intentionally or accidentally, with a few mouse
28

30

 Case 12-240, Document 219, 05/27/2016, 1781342, Page31 of 61

Goldfoot, supra, at 114 (arguing digital storage media are physical objects like
“drugs, blood, or clothing”); Wayne Jekot, Computer Forensics, Search Strategies,
and the Particularity Requirement, 7 U. Pitt. J. Tech. L. & Pol’y, art. 5, at 1, 30 (2007)
(“[A] computer does not simply hold data, it is composed of data.”). Even the
most conventional “files” — word documents and spreadsheets such as those the
Government searched in this case — are not maintained, like files in a file
cabinet, in discrete physical locations separate and distinct from other files. They
are in fact “fragmented” on a storage device, potentially across physical
locations. Jekot, supra, at 13. “Because of the manner in which data is written to
the hard drive, rarely will one file be stored intact in one place on a hard drive,”
id.; so-called “files” are stored in multiple locations and in multiple forms, see

clicks.”); Bill Nelson et al., Guide to Computer Forensics and Investigations 160 (5th ed.
2015) (emphasizing the importance of “maintain[ing] the integrity of digital evidence in
the lab” by creating a read-only copy prior to analysis); Jonathan L. Moore, Time for an
Upgrade: Amending the Federal Rules of Evidence to Address the Challenges of Electronically
Stored Information in Civil Litigation, 50 Jurimetrics J. 147, 153 (2010) (“[All electronically
stored information is] prone to manipulation[;] . . . [such] alteration can occur
intentionally or inadvertently.”); Int’l Org. for Standardization & Int’l Electrotechnical
Comm’n, Guidelines for Identification, Collection, Acquisition, and Preservation of Digital
Evidence 17 (2012) [hereinafter ISO/IEC, Guidelines] (emphasizing the importance of
careful storage and transport techniques and noting that “[s]poliation can result from
magnetic degradation, electrical degradation, heat, high or low humidity exposure, as
well as shock and vibration”).

31

 Case 12-240, Document 219, 05/27/2016, 1781342, Page32 of 61

Goldfoot, supra, at 127-28. 29 And as a corollary to this fragmentation, the
computer stores unseen information about any given “file” — not only metadata
about when the file was created or who created it, see Michael W. Graves, Digital
Archaeology: The Art and Science of Digital Forensics 94-95 (2014), but also prior
versions or edits that may still exist “in the document or associated temporary
files on [the] disk” — further interspersing the data corresponding to that “file”
across the physical storage medium, Eoghan Casey, Digital Evidence and Computer
Crime 507 (3d ed. 2011).
”Files,” in short, are not as discrete as they may appear to a user. Their
interspersion throughout a digital storage medium, moreover, may affect the
degree to which it is feasible, in a case involving search pursuant to a warrant, to
fully extract and segregate responsive data from non-responsive data. To be
clear, we do not suggest that it is impossible to do so in any particular or in every
case; we emphasize only that in assessing the reasonableness, for Fourth
Amendment purposes, of the search and seizure of digital evidence, we must be
See Goldfoot, supra (“Storage media do not naturally divide into parts,” id. at
131; “it is difficult to agree . . . on where the subcontainers begin and end,” id. at 113.);
Orin S. Kerr, Searches and Seizures in a Digital World, 119 Harv. L. Rev. 531, 557 (2005)
(“[V]irtual files are not robust concepts. Files are contingent creations assembled by
operating systems and software.”); see also Orin S. Kerr, Executing Warrants for Digital
Evidence: The Case for Use Restrictions on Nonresponsive Data, 48 Tex. Tech L. Rev. 1, 32
(2015) (“What does it mean to ‘delete’ data?”).
29

32

 Case 12-240, Document 219, 05/27/2016, 1781342, Page33 of 61

attuned to the technological features unique to digital media as a whole and to
those relevant in a particular case — features that simply do not exist in the
context of paper files.
These features include an additional complication affecting the validity of
the file cabinet analogy: namely, that a good deal of the information that a
forensic examiner may seek on a digital storage device (again, because it is a
coherent and complex forensic object and not a file cabinet) does not even
remotely fit into the typical user’s conception of a “file.” See Daniel B. Garrie &
Francis M. Allegra, Fed. Judicial Ctr., Understanding Software, the Internet, Mobile
Computing, and the Cloud: A Guide for Judges 39 (2015) (“Forensic software gives a
forensic examiner access to electronically stored information (ESI) that is
otherwise unavailable to a typical computer user.”). Forensic investigators may,
inter alia, search for and discover evidence that a file was deleted as well as
evidence sufficient to reconstruct a deleted file — evidence that can exist in socalled “unallocated” space on a hard drive. See Casey, supra, at 496; Orin S. Kerr,
Searches and Seizures in a Digital World, 119 Harv. L. Rev. 531, 542, 545 (2005); Fed.
Judicial Ctr., supra, at 40 (“A host of information can lie in the interstices between
the allocated spaces.”).

They may seek responsive metadata about a user’s

33

 Case 12-240, Document 219, 05/27/2016, 1781342, Page34 of 61

activities, or the manner in which information has been stored, to show such
things as knowledge or intent, or to create timelines as to when information was
created or accessed. 30 Forensic examiners will sometimes seek evidence on a
storage medium that something did not happen: “If a defendant claims he is
innocent because a computer virus committed the crime, the absence of a virus
on his hard drive is ‘dog that did not bark’ negative evidence that disproves his
story. . . . To prove something is not on a hard drive, it is necessary to look at
every place on the drive where it might be found and confirm it is not there.” 31
Goldfoot, supra, at 141; see also United States v. O'Keefe, 461 F.3d 1338, 1341 (11th
Cir. 2006) (“[The government’s expert] testified that the two viruses he found on
[the defendant’s] computer were not capable of ‘downloading and uploading
child pornography and sending out advertisements.’”). 32

See Fharmacy Records v. Nassar, 379 F. App’x 522, 525 (6th Cir. 2010) (describing
testimony of a digital forensics expert in a copyright case that the number and physical
location of a file on an Apple Macintosh — which saves files sequentially on its storage
medium — demonstrated that the file had been back-dated).
30

Indeed, in this very case, as already noted, see supra note 16, Ganias at one
point claimed that a “software error” or “computer flaw” prevented him from
recording certain income in his QuickBooks files. J.A. 467, ¶ 28. Data confirming the
existence, or non-existence, of an error affecting the particular installation of a program
on a given digital storage device could be, in a hypothetical case, relevant to the probity
of information otherwise located thereupon.
31

We note that some of these inferences may be limited to — or at least of more
relevance to — traditional magnetic disk drives, which have long been the primary
32

34

 Case 12-240, Document 219, 05/27/2016, 1781342, Page35 of 61

Finally, because of the complexity of the data thereon and the manner in
which it is stored, the nature of digital storage presents potential challenges to
parties seeking to preserve digital evidence, authenticate it at trial, and establish
its integrity for a fact-finder — challenges that materially differ from those in the
paper file context.

First, the extraction of specific data files to some other

digital storage technology. “Generally when data is deleted from a [traditional hard
disk drive], the data is retained until new data is written onto the same location. If no
new data is written over the deleted data, then the forensic investigator can recover the
deleted data, albeit in fragments.” Alastair Nisbet et al., A Forensic Analysis and
Comparison of Solid State Drive Data Retention with TRIM Enabled File Systems,
Proceedings of the 11th Australian Digital Forensics Conference 103 (2013). In contrast,
the technology used in solid state drives “requires a cell to be completely erased or
zeroed-out before a further write can be committed,” id. at 104, and in part because such
erasure can be time consuming, solid state drives incorporate protocols which “zerodelete data locations . . . as a matter of course,” thereby “reduc[ing] the data that can be
retrieved from the drive by [a] forensic investigator,” id. at 103. See also Graeme B. Bell
& Richard Boddington, Solid State Drives: The Beginning of the End for Current Practice in
Digital Forensic Recovery?, 5 J. Digital Forensics, Sec. & L., no. 3, 2010, at 1, 12 (stating
that, in connection with such storage devices, “evidence indicating ‘no data’ does not
authoritatively prove that data did not exist at the time of capture”). That is not to say
that studies indicate that deleted information is never recoverable from any model of
solid state drive. See, e.g., Christopher King & Timothy Vidas, Empirical Analysis of Solid
State Disk Data Retention When Used with Contemporary Operating Systems, 8 Digital
Investigation 111, 113 (2011) (citing a study suggesting that data deleted from a
particular solid state drive was recoverable in certain contexts); Gabriele Bonetti et al., A
Comprehensive Black-Box Methodology for Testing the Forensic Characteristics of Solid-State
Drives, Proceedings of the 29th Annual Computer Security Applications Conference 277
(2013) (observing that, though several tested solid state drives contained no recoverable
deleted data, one model contained “high[ly] recoverab[le]” quantities of such data).
The point is simply that there may be material differences among different varieties of
storage media that, in turn, make certain factors cited herein more or less relevant to a
given inquiry.

35

 Case 12-240, Document 219, 05/27/2016, 1781342, Page36 of 61

medium can alter, omit, or even destroy portions of the information contained in
the original storage medium. Preservation of the original medium or a complete
mirror may therefore be necessary in order to safeguard the integrity of evidence
that has been lawfully obtained or to authenticate it at trial. Graves, supra, at 9596 (“[The investigator] must be able to prove that the information presented
came from where he or she claims and was not altered in any way during
examination, and that there was no opportunity for it to have been replaced or
altered in the interim.”); see also Casey, supra, at 480 (“Even after copying data
from a computer or piece of storage media, digital investigators generally retain
the original evidential item in a secure location for future reference.”). 33

The

preservation of data, moreover, is not simply a concern for law enforcement.
We do not suggest that authentication of evidence from computerized records
is impossible absent retention of an entire hard drive or mirror. Authentication is
governed by Federal Rule of Evidence 901, which requires only that “the proponent
must produce evidence sufficient to support a finding that the item is what the
proponent claims it is.” Fed. R. Evid. 901(a). As we have stated, “[t]his requirement is
satisfied ‘if sufficient proof has been introduced so that a reasonable juror could find in
favor of authenticity or identification.’” United States v. Pluta, 176 F.3d 43, 49 (2d Cir.
1999) (citation omitted) (quoting United States v. Ruggiero, 928 F.2d 1289, 1303 (2d Cir.
1991)). “[T]he burden of authentication does not require the proponent of the evidence
to rule out all possibilities inconsistent with authenticity, or to prove beyond any doubt
that the evidence is what it purports to be. Rather, the standard for authentication, and
hence for admissibility, is one of reasonable likelihood.” Id. (alteration omitted)
(quoting United States. v. Holmquist, 36 F.3d 154, 168 (1st Cir. 1994)). The weight of
digital evidence admitted at trial, however, may be undermined by challenges to its
integrity — challenges which proper preservation might have otherwise avoided.
33

36

 Case 12-240, Document 219, 05/27/2016, 1781342, Page37 of 61

Retention of the original storage medium or its mirror may also be necessary to
afford criminal defendants access to that medium or its forensic copy so that,
relying on forensic experts of their own, they may challenge the authenticity or
reliability of evidence allegedly retrieved. See, e.g., United States v. Kimoto, 588
F.3d 464, 480 (7th Cir. 2009) (quoting the defendant’s motion as stating: “Upon
beginning their work, [digital analysis experts] advised [the defendant’s]
Counsel that the discovery provided to the defense did not appear to be a
complete forensic copy, and that such was necessary to verify the data as
accurate and unaltered.”). 34 Defendants may also require access to a forensic
copy to conduct an independent analysis of precisely what the government’s
forensic expert did — potentially altering evidence in a manner material to the
case — or to locate exculpatory evidence that the government missed. 35

Where, as in this case, a mirror containing responsive data has been lawfully
seized from a third-party custodian, this concern cannot be avoided simply by
returning the original medium to the party from whom it was seized. A third-party
custodian may need to utilize a hard drive in ways that will alter the data, and will
likely have no incentive to retain a mirrored copy of drives as they once existed but that
are of no further use to the custodian.
34

See Kimoto, 588 F.3d at 480-81 (“[The defendant] argued that the failure to
provide him with a complete forensic copy of all digital files impaired his ability to
prepare a defense. . . . [The defendant] submitted that he should not be punished
‘because the Government failed to properly preserve or maintain a digital forensic copy
of the data.’”); Casey, supra, at 510-11 (discussing a case study in which, due to forensic
investigators’ own mistakes, discovery of digital evidence confirming a murder
35

37

 Case 12-240, Document 219, 05/27/2016, 1781342, Page38 of 61

Notwithstanding any other distinctions between this case and Tamura,
then, the Government plausibly argues that, because digital storage media
constitute coherent forensic objects with contours more complex than — and
materially distinct from — file cabinets containing interspersed paper
documents, a digital storage medium or its forensic copy may need to be
retained, during the course of an investigation and prosecution, to permit the
accurate extraction of the primary evidentiary material sought pursuant to the
warrant; to secure metadata and other probative evidence stored in the
interstices of the storage medium; and to preserve, authenticate, and effectively
present at trial the evidence thus lawfully obtained. To be clear, we do not
decide the ultimate merit of this argument as applied to the circumstances of this
case.

36

Nor do we gainsay the privacy concerns implicated when the

suspect’s alibi was greatly delayed); see also id. at 508-510 (detailing the importance of
experts reporting their processes); Fed. Judicial Ctr., supra, at 41 (“The forensic
examiner . . . generate[s] reports, detailing the protocols and processes that he or she
followed . . . . The forensic reports must provide enough data to allow an independent
third-party examiner to recreate the exact environment that yielded the report’s
findings and observations.”); Darren R. Hayes, A Practical Guide to Computer Forensics
Investigations 116 (2015) (“[B]ecause forensics is a science, the process by which the
evidence was acquired must be repeatable, with the same results.”); ISO/IEC, Guidelines,
supra, at 7 (emphasizing the importance of repeatability and reproducibility).
That said, it is important to correct a misunderstanding in the dissent’s
analysis, as it pertains to these factors and their application here. The dissent suggests
that the Government can have had no interest in retention, as “[t]he agents could not
36

38

 Case 12-240, Document 219, 05/27/2016, 1781342, Page39 of 61

government retains a hard drive or forensic mirror containing personal
information irrelevant to the ongoing investigation, even if such information is
never viewed. We discuss the aptness and limitations of Ganias’s analogy and
have been keeping non-responsive files [in order to authenticate and defend the probity
of responsive files] for the purpose of proceeding against Ganias, as [in December 2004]
they did not yet suspect [him] of criminal wrongdoing.” Dissent at 22. This argument
misunderstands the Government’s position: the Government was not retaining the
mirrors in late 2004 and 2005 in the hopes of proceeding against Ganias; it was retaining
the mirrors as part of its ongoing investigation of James McCarthy and his two
companies, AB and IPM — an investigation that would culminate in an indictment of
McCarthy in 2008 secured through extensive reliance on responsive data recovered
from the mirrored copies of Ganias’s hard drives. The dissent’s focus on Ganias, the
owner of the hard drives the Government mirrored, and not McCarthy, a third-party
defendant, thus permits the dissent to dismiss out-of-hand Government interests that,
properly viewed, are significant — whether or not ultimately dispositive. See Dissent at
24 (“As a practical matter, a claim of data tampering would easily fall flat where, as
here, the owner kept his original computer and the Government gave him a copy of the
mirror image.”); id. at 25-26 (dismissing the Government’s Brady concern by noting that
“[t]he Government is essentially arguing that it must hold on to the materials so that it
can give them back to the defendant,” a concern that the dissent argues “can be
obviated simply by returning the non-responsive files to the defendant in the first
place”). Perhaps in some situations, in which the owner of computerized data seized
pursuant to a search warrant is the expected defendant in a criminal proceeding,
problems of authentication or probity could be handled by stipulations, and Brady
issues might be mooted by the return of the data to the defendant — though we express
no view on those questions. As this case illustrates, however, when the owner of hard
drives mirrored by the government is a third party who is not the expected target of the
investigation, the government’s interests in retention take on an additional layer of
complexity. A stipulation with Ganias about the authenticity or probity of data
extracted from his computers would not have affected the ability of the original targets
of the investigation to raise challenges to authenticity or probity. Nor would returning
the mirrors to Ganias — who at that point, absent a stipulation to the contrary, could
presumably have destroyed or altered them, intentionally or accidentally — have
protected the interests of those anticipated defendants in conducting their own forensic
examination of the data in search of exculpatory evidence or to replicate and criticize
the Government’s inspection procedures.

39

 Case 12-240, Document 219, 05/27/2016, 1781342, Page40 of 61

the Government’s response simply to highlight the complexity of the relevant
questions for future cases and to underscore the importance, in answering such
questions, of engaging with the technological specifics. 37

Of course, engaging with the specifics requires acknowledging and
emphasizing that technologies rapidly evolve, and that the specifics change. See John
Sammons, The Basics of Digital Forensics 170 (2012) (commenting that digital forensics
faces the “blinding speed of technology [and] new game-changing technologies such as
cloud computing and solid state hard drives . . . just to name a few”). In discussing the
technological specifics of computer hard drives, we have primarily addressed a
particular form of electronic storage that has become conventional. See supra note 32.
Newer forms of emerging storage technology, or future developments, may work
differently and thus present different challenges. See, e.g., Bell & Boddington, supra, at
3, 6, 14 (observing that “the peculiarity of ‘deleted, but not forgotten’ data which so
often comes back to haunt defendants in court is in many ways a bizarre artefact of hard
drive technology” and that increasingly popular solid state drives can “modify
themselves very substantially without receiving instructions to do so from a computer,”
and thus predicting that “recovery of deleted files and old metadata will become
extremely difficult, if not impossible” as solid state storage devices utilizing a particular
deletion protocol called “TRIM” become more prevalent); King & Vidas, supra, at 111
(“We show that on a TRIM-enabled [solid state drive], using an Operating System (OS)
that supports TRIM, . . . in most cases no data can be recovered.”); id. at 113 (“[M]ost
[solid state drive] manufacturers have a TRIM-enabled drive model currently on the
market.”). But see Bonetti et al., supra, at 270-71, 278 (making clear that solid state
drives, which differ considerably among models and vendors, may yield differing
levels of deleted-file recoverability, depending upon their utilization of TRIM and other
deletion protocols, erasing patterns, compression, and wear leveling protocols). Solid
state drives, of course, are just one example. Cf. Bell & Boddington, supra, at 3 (“It is . . .
in the nature of computing that we perceive regular paradigm shifts in the ways that we
store and process information.”). The important point is that considerations discussed
in this opinion may well become obsolete at some future point, the challenges facing
forensic examiners and affected parties may change, and courts dealing with these
problems will need to become conversant with the particular forms of technology
involved in a given case and the evidentiary challenges presented by those forms.
37

40

 Case 12-240, Document 219, 05/27/2016, 1781342, Page41 of 61

In emphasizing such specifics, we reiterate that we do not mean to thereby
minimize or ignore the privacy concerns implicated when a hard drive or
forensic mirror is retained, even pursuant to a warrant.

The seizure of a

computer hard drive, and its subsequent retention by the government, can give
the government possession of a vast trove of personal information about the
person to whom the drive belongs, much of which may be entirely irrelevant to
the criminal investigation that led to the seizure. Indeed, another weakness of
the file cabinet analogy is that no file cabinet has the capacity to contain as much
information as the typical computer hard drive. In 2005, Professor Orin Kerr
noted that the typical personal computer hard drive had a storage capacity of
about eighty gigabytes, which he estimated could hold text files equivalent to the
“information contained in the books on one floor of a typical academic library.”
Kerr, Searches and Seizures in a Digital World, supra, at 542. By 2011, computers
were being sold with one terabyte of capacity — about twelve times the size of
Professor Kerr’s library floor. Paul Ohm, Response, Massive Hard Drives, General
Warrants, and the Power of Magistrate Judges, 97 Va. L. Rev. In Brief 1, 6 (2011). The
New York Times recently reported that commercially available storage devices can
hold “16 petabytes of data, roughly equal to 16 billion thick books.” Quentin

41

 Case 12-240, Document 219, 05/27/2016, 1781342, Page42 of 61

Hardy, As a Data Deluge Grows, Companies Rethink Storage, N.Y. Times, Mar. 15,
2016, at B3.
Moreover, quantitative measures fail to capture the significance of the data
kept by many individuals on their computers. Tax records, diaries, personal
photographs, electronic books, electronic media, medical data, records of internet
searches, banking and shopping information — all may be kept in the same
device, interspersed among the evidentiary material that justifies the seizure or
search. Cf. Riley v. California, 134 S. Ct. 2473, 2489-90 (2014) (explaining that even
microcomputers, such as cellphones, have “immense storage capacity” that may
contain “every piece of mail [people] have received for the past several months,
every picture they have taken, or every book or article they have read,” which
can allow the “sum of an individual’s private life [to] be reconstructed”); United
States v. Galpin, 720 F.3d 436, 446 (2d Cir. 2013) (“[A]dvances in technology and
the centrality of computers in the lives of average people have rendered the
computer hard drive akin to a residence in terms of the scope and quantity of
private information it may contain.”). While physical searches for paper records
or other evidence may require agents to rummage at least cursorily through
much private material, the reasonableness of seizure and subsequent retention

42

 Case 12-240, Document 219, 05/27/2016, 1781342, Page43 of 61

by the government of such vast quantities of irrelevant private material was
rarely if ever presented in cases prior to the age of digital storage, and has never
before been considered justified, or even practicable, in such cases. Even as we
recognize that search and seizure of digital media is, in some ways, distinct from
what has come before, we must remain mindful of the privacy interests that
necessarily inform our analysis. 38
We note, however, that parties with an interest in retained storage media
are not without recourse. As noted above, Ganias never sought the return of any
seized material, either by negotiating with the Government or by motion to the
court. Though negotiated stipulations regarding the admissibility or integrity of
evidence may not always suffice to satisfy reasonable interests of the government

The dissent extensively addresses these privacy interests. As this opinion
makes clear, we do not disagree with the proposition that the seizure and retention of
computer hard drives or mirrored copies of those drives implicate such concerns and
raise significant Fourth Amendment questions. We do not agree, however, for reasons
we have also discussed at length, with the dissent’s dismissal of the countervailing
government concerns. However these issues are ultimately resolved, we believe that
the Government’s arguments are, at a minimum, sufficiently forceful that it is unwise to
try to reach definitive conclusions about the constitutional issues in a case that can be
decided on other grounds.
38

43

 Case 12-240, Document 219, 05/27/2016, 1781342, Page44 of 61

in retention during the pendency of an investigation, 39 such stipulations may
make return feasible in a proper case, and can be explored.
A person from whom property is seized by law enforcement may move for
its return under Federal Rule of Criminal Procedure 41(g). 40 Rule 41(g) permits a
defendant or any “person aggrieved” by either an unlawful or lawful deprivation
of property, see United States v. Comprehensive Drug Testing, Inc., 621 F.3d 1162,
1173 (9th Cir. 2010) (en banc) (per curiam), to move for its return, Fed. R. Crim. P.
41(g). Evaluating such a motion, a district court “must receive evidence on any
factual issue necessary to decide the motion,” and, in the event that the motion is
granted, may “impose reasonable conditions to protect access to the property
and its use in later proceedings.”

Id.

Since we resolve this case on other

For instance, as we have previously noted, where, as here, the owner of the
records is not (at least at the time of the seizure) the target of the investigation, a
stipulation from that party may not serve the government’s need to establish the
authenticity or integrity of evidence it may seek to use, and access to the records by that
party will not necessarily satisfy the need of potential future defendants to test the
processes used by the government to extract or accurately characterize data culled from
a hard drive. In some cases, however, negotiated solutions may be practicable.
39

40

Rule 41(g) provides as follows:

Motion to Return Property. A person aggrieved by an unlawful search
and seizure of property or by the deprivation of property may move for
the property's return. The motion must be filed in the district where the
property was seized. The court must receive evidence on any factual issue
necessary to decide the motion. If it grants the motion, the court must
return the property to the movant, but may impose reasonable conditions
to protect access to the property and its use in later proceedings.

44

 Case 12-240, Document 219, 05/27/2016, 1781342, Page45 of 61

grounds, we need not address whether Ganias’s failure to make such a motion
forfeited any Fourth Amendment objection he might otherwise have had to the
Government’s retention of the mirrors. But we agree with the district court that,
as a pragmatic matter, such a motion “would have given a court the opportunity
to consider ‘whether the government’s interest could be served by an alternative
to retaining the property,’ and perhaps to order the [mirrors] returned to Ganias,
all while enabling the court to ‘impose reasonable conditions to protect access to
the property and its use in later proceedings.’” Ganias, 2011 WL 2532396, at *8
(citation omitted) (first quoting In re Smith, 888 F.2d 167, 168 (D.C. Cir. 1989) (per
curiam); then quoting Fed. R. Crim. P. 41(g)).
Rule 41(g) thus provides a potential mechanism, in at least some contexts,
for dealing with the question of retention at a time when the government may be
expected to have greater information about the data it seeks and the best process
through which to search and present that data in court. It is worth observing,
then, that Rule 41(g) constitutes a statutory solution (as opposed to a purely
judicially constructed one) to at least one facet of the retention problem. 41

The advisory committee notes to the 2009 amendments to Federal Rule of
Criminal Procedure 41(e)(2)(B) contemplate that Rule 41(g) may indeed constitute such
a solution. Regarding specifically the seizure of electronic storage media or the search
41

45

 Case 12-240, Document 219, 05/27/2016, 1781342, Page46 of 61

Statutory approaches, of course, do not relieve courts from their obligation to
interpret the Constitution; nevertheless, such approaches have, historically,
provided one mechanism for safeguarding privacy interests while, at the same
time, addressing the needs of law enforcement in the face of technological
change. Indeed, when Congress addressed wiretapping in the Omnibus Crime
Control and Safe Streets Act of 1968, the Senate Judiciary Committee issued a
report reflecting precisely this ambition — to provide a framework through
which law enforcement might comport with the demands of the Constitution
and meet important law enforcement interests. See S. Rep. No. 90-1097, at 66-76
(1968) (describing the construction of the then-Omnibus Crime Control and Safe
Streets of Act of 1967, which laid out comprehensive rules for when and how law
enforcement could intercept wire and oral communications through electronic
surveillance, as a Congressional attempt to respond to and synthesize, first,
technological change, id. at 67, second, ineffective or unclear state statutory
of electronically stored information, the advisory committee notes observe that though
the rule does not create
a presumptive national or uniform time period within which . . . off-site
copying or review of . . . electronically stored information would take
place, . . . [i]t was not the intent of the amendment to leave the property
owner without . . . a remedy[:] . . . Rule 41(g) . . . provides a process for the
“person aggrieved” to seek an order from the court for a return of the
property, including storage media or electronically stored information,
under reasonable circumstances.

46

 Case 12-240, Document 219, 05/27/2016, 1781342, Page47 of 61

regimes, id. at 69, third, evolving Supreme Court precedent, id. at 74-75, and
fourth, law enforcement concerns, id. at 70); see also id. at 66 (“Title III has as its
dual purpose (1) protecting the privacy of wire and oral communications, and
(2) delineating on a uniform basis the circumstances and conditions under which
the interception of wire and oral communications may be authorized.”). The Act
did not seek to supplant the role of the courts, nor could it have done so, but it
did demonstrate the intuitive proposition that Congress can and should be a
partner in the process of fleshing out the contours of law-enforcement policy in a
shifting technological landscape. In acknowledging the role of Rule 41(g), then,
we seek also to suggest that search and seizure of electronic media may, no less
than wiretapping, merit not only judicial review but also legislative analysis;
courts need not act alone.
As we have said, we need not resolve the ultimate question whether the
Government’s retention of forensic copies of Ganias’s hard drives during the
pendency of its investigation violated the Fourth Amendment. We conclude,
moreover, that we should not decide this question on the present record, which
does not permit a full assessment of the complex and rapidly evolving
technological issues, and the significant privacy concerns, relevant to its

47

 Case 12-240, Document 219, 05/27/2016, 1781342, Page48 of 61

consideration. 42 Having noted Ganias’s argument, we do not decide its merits.
We instead turn to the question of good faith.

The dissent faults us for our caution in this regard, suggesting that “the
prevailing scholarly consensus has been that the [original Ganias] panel largely got it
right.” Dissent at 5 n.5. With respect, the dissent mischaracterizes the scholarly
response. As an initial matter, the dissent cites Professor Kerr as having concluded that
the panel “largely got it right.” Id. In fact, Kerr’s analysis of the original panel opinion
is generally critical, not complimentary. See Kerr, Executing Warrants for Digital
Evidence, supra, at 32 (critiquing the panel for going too far and thus offering a
“particularly strong version” of Kerr’s approach). Assessing the original panel’s
analysis, Kerr first concludes that, given the technological contours of electronic media,
an affirmative obligation to delete could be “difficult to implement,” just as it could be
difficult to ascertain at what point in the process such a “duty [would be] triggered.” Id.
Second, Kerr concludes that — to the degree that restrictions should be placed upon
what the government may do with non-responsive data that must, for pragmatic
reasons, be retained — a restriction preventing the government from viewing data
pursuant to a search warrant acquired with independent probable cause is unnecessary
“to restore the basic limits of search warrants in a world of digital evidence.” Id. at 33.
Apart from this citation to Kerr and to two student notes (which reach differing
conclusions about the merits of the panel opinion), the articles the dissent cites (as is
evident from the carefully worded parentheticals the dissent itself provides) are not
evaluations of the original panel opinion, but instead provide largely descriptive
accounts of the opinion and its relation to other case law in the context of making other
points. The signed article that comes the closest to providing a normative critique of the
panel’s opinion concludes that “perhaps the panel’s answer is broadly the right answer,”
but rejects the panel’s — and the dissent’s — reasoning. Stephen E. Henderson, Fourth
Amendment Time Machines (and What They Might Say About Police Body Cameras), 18 U.
Pa. J. Const. L. 933, 948 (2016) (emphasis added); see id. at 947 (concluding that, because
“in 2003 and in 2006 the government obtained a warrant demonstrating particularized
suspicion towards Ganias’s data, and in each instance agents thereafter only looked for
the responsive data,” it was inapt for the original panel to conclude that the
Government’s position would transform a warrant for electronic data into a “general
warrant”). We do not opine on these issues here, but we see no scholarly consensus on
the complicated questions implicated in this case that would suggest caution is illadvised in a matter where these questions need not be answered to reach a resolution.
Caution, although not always satisfying, is sometimes the most appropriate approach.
42

48

 Case 12-240, Document 219, 05/27/2016, 1781342, Page49 of 61

III
The Government argues that, because it acted in good faith throughout the
pendency of this case, any potential violation of the Fourth Amendment does not
justify the extraordinary remedy of suppression. See Davis v. United States, 564
U.S. 229, 237 (2011) (noting the “heavy toll” exacted by suppression, which
“requires courts to ignore reliable, trustworthy evidence,” and characterizing
suppression as a “bitter pill,” to be taken “only as a ‘last resort’” (quoting Hudson
v. Michigan, 547 U.S. 586, 591 (2006))); accord United States v. Clark, 638 F.3d 89, 99
(2d Cir. 2011). In particular, the Government urges that its “reliance on the 2006
warrant,” which it obtained after disclosing to the magistrate judge all relevant
facts regarding its retention of the mirrored files, “fits squarely within the
traditional Leon exception for conduct taken in reliance on a search warrant
issued by a neutral and detached magistrate judge.” 43 Government Br. at 59; see
Leon, 468 U.S. at 922. For the following reasons, we agree.

The Government also contends: (1) that it relied in good faith on the 2003
warrant in retaining the mirrors; and (2) that its behavior was in no way culpable,
rendering exclusion inappropriate, see Government Br. at 51; see also Herring v. United
States, 555 U.S. 135, 144 (2009) (“[T]he exclusionary rule serves to deter deliberate,
reckless, or grossly negligent conduct, or in some circumstances recurring or systemic
negligence.”); accord Davis, 546 U.S. at 237. Given our conclusion that the Government
relied in good faith on the 2006 warrant, we need not address these additional
arguments.
43

49

 Case 12-240, Document 219, 05/27/2016, 1781342, Page50 of 61

In Leon, the Supreme Court determined that the exclusion of evidence is
inappropriate when the government acts “in objectively reasonable reliance” on
a search warrant, even when the warrant is subsequently invalidated. 468 U.S. at
922; see also Clark, 638 F.3d at 100 (“[I]n Leon, the Supreme Court strongly
signaled that most searches conducted pursuant to a warrant would likely fall
within its protection.”). Such reliance, however, must be objectively reasonable.
See Leon, 468 U.S. at 922-23 (“[I]t is clear that in some circumstances the officer
will have no reasonable grounds for believing that the warrant was properly
issued.” (footnote omitted)). Thus, to assert good faith reliance successfully,
officers must, inter alia, disclose all potentially adverse information to the issuing
judge. See United States v. Reilly, 76 F.3d 1271, 1280 (2d Cir.) (“The good faith
exception to the exclusionary rule does not protect searches by officers who fail
to provide all potentially adverse information to the issuing judge . . . .”), aff’d and
amended, 91 F.3d 331 (2d Cir. 1996) (per curiam); see also United States v. Thomas,
757 F.2d 1359, 1368 (2d Cir. 1985) (finding good faith reliance on a warrant, under
Leon, where officers, first, committed a constitutional violation they did not
reasonably know, at the time, was unconstitutional — a warrantless canine sniff
— and second, in relying on evidence from this sniff in a warrant application,

50

 Case 12-240, Document 219, 05/27/2016, 1781342, Page51 of 61

fully revealed the fact of the canine sniff to a magistrate judge), cert. denied by
Fisher v. United States, 474 U.S. 819 (1985) and Rice v. United States, 479 U.S. 818
(1986).
Ganias argues that reliance on the 2006 warrant is misplaced for two
reasons. First, he urges that the alleged constitutional violation here (unlawful
retention of the mirrored drives) had “long since” ripened into a violation by
April 2006, when the second warrant was obtained, Appellant Br. at 55-56, and
attests that “[n]othing [in Leon] suggests that the police, after they engage in
misconduct, can then ‘launder their prior unconstitutional behavior by
presenting the fruits of it to a magistrate,’” id. at 56 (quoting State v. Hicks, 707
P.2d 331, 333 (Ariz. Ct. App. 1985)). Second, Ganias argues that, even if “a
subsequent warrant can ever appropriately purge the taint of an earlier violation,
the agent must, at the very least, ‘provide all potentially adverse information’
regarding the earlier illegality ‘to the issuing [magistrate] judge,’” a requirement
that he argues was not satisfied here. Id. at 58 (quoting Reilly, 76 F.3d at 1280).
Ganias’s arguments are unavailing.
First, Ganias relies on this Court’s decision in Reilly to argue categorically
that agents who have engaged in a predicate Fourth Amendment violation may

51

 Case 12-240, Document 219, 05/27/2016, 1781342, Page52 of 61

not rely on a subsequently issued warrant to establish good faith.

Reilly,

however, stands for no such thing. In Reilly, officers unlawfully intruded on the
defendant’s curtilage, discovering about twenty marijuana plants, before they
departed and obtained a search warrant based on a “bare-bones” description of
their intrusion and resulting observations which this Court found “almost
calculated to mislead.”

Reilly, 76 F.3d at 1280; see also id. (“[The affidavit]

simply . . . stated that [the officers] walked along Reilly’s property until they
found an area where marijuana plants were grown. It did not describe this area
to the Judge[,] . . . [and it] gave no description of the cottage, pond, gazebo, or
other characteristics of the area. . . . [The omitted information] was crucial.
Without it, the issuing judge could not possibly make a valid assessment of the
legality of the warrant that he was asked to issue.”).

We rejected the

government’s argument that the officers were entitled to rely on the warrant,
noting that the officers had “undert[aken] a search that caused them to invade
what they could not fail to have known was potentially . . . curtilage,” and that
they thereafter “failed to provide [the magistrate issuing the warrant] with an
account of what they did,” so that the magistrate was unable to ascertain
whether the evidence on which the officers relied in seeking the warrant was

52

 Case 12-240, Document 219, 05/27/2016, 1781342, Page53 of 61

“itself obtained illegally and in bad faith.” Id. at 1281. In such circumstances,
Leon did not — and does not — permit good faith reliance on a warrant. See
Leon, 468 U.S. at 923 (observing that an officer’s reliance on a warrant is not
objectively reasonable if he “misled [the magistrate with] information in an
affidavit that [he] knew was false or would have known was false except for his
reckless disregard of the truth”).
The present case, however, is akin not to Reilly, but to this Court’s decision
in Thomas, which the Reilly panel carefully distinguished, while reaffirming. See
Reilly, 76 F.3d at 1281-82. In Thomas, an agent, acting without a warrant, used a
dog trained to detect narcotics to conduct a “canine sniff” at a dwelling. 757 F.2d
at 1367. The agent presented evidence acquired as a result of the sniff to a
“neutral and detached magistrate” who, on the basis of this and other evidence,
determined that the officer had probable cause to conduct a subsequent search of
the dwelling in question. Id. at 1368. The defendant moved to suppress the
evidence found in executing the search warrant, arguing that the antecedent
canine sniff constituted a warrantless, unconstitutional search and that the
evidence acquired from that sniff was dispositive to the magistrate judge’s
finding of probable cause. See id. at 1366. This Court agreed on both counts: first

53

 Case 12-240, Document 219, 05/27/2016, 1781342, Page54 of 61

deciding, as a matter of first impression in our Circuit, that the canine sniff at
issue constituted a search, id. at 1367, and second determining that, absent the
evidence acquired from this search, the warrant was not supported by probable
cause, id. at 1368. The Thomas panel nevertheless concluded that suppression
was inappropriate because the agent’s reliance on the warrant was objectively
reasonable: “The . . . agent brought his evidence, including [a factual description
of the canine sniff], to a neutral and detached magistrate.

That magistrate

determined that probable cause to search existed, and issued a search warrant.
There is nothing more the officer could have or should have done under these
circumstances to be sure his search would be legal.” Id.
Reilly carefully distinguished Thomas, and in a manner that makes
apparent that it is Thomas that is dispositive here. First, the Reilly panel noted
that Thomas was unlike Reilly, in that the agent in Thomas disclosed all crucial
facts for the legal determination in question to the magistrate judge. Reilly, 76
F.3d at 1281. Then, the Reilly panel articulated another difference: while in Reilly,
“the officers undertook a search that caused them to invade what they could not
fail to have known was potentially Reilly’s curtilage,” in Thomas, the agent “did
not have any significant reason to believe that what he had done [conducting the

54

 Case 12-240, Document 219, 05/27/2016, 1781342, Page55 of 61

canine sniff] was unconstitutional.” Id.; see also id. (“[U]ntil Thomas was decided,
no court in this Circuit had held that canine sniffs violated the Fourth
Amendment.”). Thus, the predicate act in Reilly tainted the subsequent search
warrant, whereas the predicate act in Thomas did not. The distinction did not
turn on whether the violation found was predicate, or prior to, the subsequent
search warrant on which the officers eventually relied, but on whether the
officers’ reliance on the warrant was reasonable.
Contrary to Ganias’s argument, then, it is not the case that good faith
reliance on a warrant is never possible in circumstances in which a predicate
constitutional violation has occurred. The agents in Thomas committed such a
violation, but they had no “significant reason to believe” that their predicate act
was indeed unconstitutional, Reilly, 76 F.3d at 1281, and the issuing magistrate
was apprised of the relevant conduct, so that the magistrate was able to
determine whether any predicate illegality precluded issuance of the warrant. In
such circumstances, invoking the good faith doctrine does not “launder [the
agents’] prior unconstitutional behavior by presenting the fruits of it to a
magistrate,” as Ganias suggests. Appellant Br. at 56 (quoting Hicks, 707 P.2d at
333). In such cases, the good faith doctrine simply reaffirms Leon’s basic lesson:

55

 Case 12-240, Document 219, 05/27/2016, 1781342, Page56 of 61

that suppression is inappropriate where reliance on a warrant was “objectively
reasonable.” Leon, 468 U.S. at 922. 44
Such is the case here. First, Agent Hosney provided sufficient information
in her affidavit to apprise the magistrate judge of the pertinent facts regarding
the retention of the mirrored copies of Ganias’s hard drives — the alleged
constitutional violation on which he relies. Agent Hosney explained that the
mirror images in question had been “seized on November 19, 2003 from the
offices of Taxes International,” J.A. 461, ¶ 7; that information material to the
initial investigation of a third party had been located on the mirrors and
“analyzed in detail,” J.A. 464, ¶ 15; that Ganias was not, at the time of the
original seizure, under investigation, J.A. 461, ¶ 3; that, “[p]ursuant to [that initial
warrant],” Agent Hosney could not search Ganias’s personal or business files as

Insofar as Ganias argues that Thomas’s and Reilly’s holdings are limited to
when the alleged predicate violation is a search that taints the warrant, but do not
extend to circumstances in which the alleged predicate violation is a seizure or unlawful
retention, we discern no justification for this distinction. But for the canine search in
Thomas — the predicate violation — there would have been no subsequent warrant
pursuant to which the government searched the dwelling and on whose legality it
relied in conducting that search. But for the retention in this case — the alleged
predicate violation — there could have been no subsequent search warrant pursuant to
which the Government searched the relevant evidence and on whose legality the
Government relied in conducting that search. To credit Ganias’s distinction would be
to replace the underlying directive that reliance on a warrant be “objectively
reasonable,” Leon, 468 U.S. at 922, with an arbitrary formalism.
44

56

 Case 12-240, Document 219, 05/27/2016, 1781342, Page57 of 61

the warrant authorized search only of “files for [AB] and IPM,” J.A. 464, ¶ 14;
and that Ganias’s personal data — which Agent Hosney was not authorized to
search — was on those mirrored drives, J.A. 467, ¶ 27, and thus, a fortiori, had been
there for the past two and a half years. The magistrate judge was thus informed
of the fact that mirrors containing data non-responsive to the 2003 warrant had
been retained for several years past the initial execution of that warrant and, to
the degree it was necessary, that data responsive to the 2003 warrant had been
analyzed in detail. The magistrate therefore had sufficient information on which
to determine whether such retention precluded issuance of the 2006 warrant. Cf.
Thomas, 757 F.2d at 1368 (“The magistrate, whose duty it is to interpret the law,
determined that the canine sniff could form the basis for probable cause . . . .”).
Ganias disagrees, arguing, in particular, that, though Agent Hosney
alerted the magistrate that the mirrors had been retained for several years; that
data responsive to the original warrant had been both located and extensively
analyzed; and that those of Ganias’s QuickBooks files that Agent Hosney wanted
to search were non-responsive to the original warrant, the Hosney affidavit did
not go far enough in that it failed to disclose that the agents “had been retaining
the non-responsive records for a full 16 months after the files within the

57

 Case 12-240, Document 219, 05/27/2016, 1781342, Page58 of 61

November 2003 warrant’s scope had been identified.” Appellant Br. at 60. As an
initial matter, the Government did alert the magistrate that it had located
responsive data on the mirrors and conducted extensive analysis of that
responsive material, and it is not clear what else the Government should have
said: the district court did not determine — nor does the record show — that by
January 2005, as Ganias contends, the Government had determined, as a
forward-looking matter, that it had performed all forensic searches of data
responsive to the 2003 warrant that might prove necessary over the course of its
investigation. Compare J.A. 322 (Q: “So it’s fair to say that as of mid-December
[2004], your forensic analysis was completed at that time?” Agent Chowaniec:
“That’s correct, of the computers.”), with J.A. 324 (Q: “Did you know you
wouldn’t require further analysis by Greg Norman or any other examiner at the
Army lab in Georgia after December of 2004?” Agent Chowaniec: “No.”); see
supra note 12. Nor would it be reasonable to expect additional detail in the
affidavit on this point, even assuming Ganias’s contention to be correct that the
Government had both finished its segregation and provided insufficient facts to
alert the magistrate judge to that reality, given the dearth of precedent
suggesting its relevance.

Cf. Clark, 638 F.3d at 105 (“[W]here the need for

58

 Case 12-240, Document 219, 05/27/2016, 1781342, Page59 of 61

specificity in a warrant or warrant affidavit on a particular point was not yet
settled or was otherwise ambiguous, we have declined to find that a well-trained
officer could not reasonably rely on a warrant issued in the absence of such
specificity.”); cf. Reilly, 76 F.3d at 1280 (noting that the affidavit in that case, in
clear contrast to the affidavit in this one, was “almost calculated to mislead”).
Second, here, as in Thomas, it is also clear that the agents, as the panel put it
in Reilly, “did not have any significant reason to believe that what [they] had
done was unconstitutional,” Reilly, 76 F.3d at 1281 — that their retention of the
mirrored hard drives, while the investigation was ongoing, was anything but
routine. At the time of the retention, no court in this Circuit had held that
retention of a mirrored hard drive during the pendency of an investigation could
violate the Fourth Amendment, much less that such retention would do so in the
circumstances presented here. See id. (noting that suppression was inappropriate
in Thomas in part because no relevant precedent established that canine sniffs of a
dwelling “violated the Fourth Amendment”). 45 Moreover, as noted above, the

The closest decision Ganias can locate is United States v. Tamura, 694 F.2d at
594-95, an out-of-circuit case that concerned intermingled paper files, the removal of
which was unauthorized and the return of which had been vigorously sought by the
affected parties. Whatever relevance that case may have by analogy, it is not sufficient
to alert a reasonable agent to the existence of a serious Fourth Amendment problem: for
to suggest that a holding applicable to retaining intermingled paper files specifically
45

59

 Case 12-240, Document 219, 05/27/2016, 1781342, Page60 of 61

2003 warrant authorized the lawful seizure not merely of particular records or
data, but of the hard drives themselves, or in the alternative the creation of
mirror images of the drives to be removed from the premises for later forensic
evaluation, and set no greater limit on the Government’s retention of those
materials than on any other evidence whose seizure it authorized.
Finally, the record here is clear that the agents acted reasonably
throughout the investigation. They sought authorization in 2003 to seize the
hard drives and search them off-site; they minimized the disruption to Ganias’s
business by taking full forensic mirrors; they searched the mirrors only to the
extent authorized by, first, the 2003 warrant, and then the warrant issued in 2006;
they were never alerted that Ganias sought the return of the mirrors; and they
alerted the magistrate judge to these pertinent facts in applying for the second
warrant. In short, the agents acted reasonably in relying on the 2006 warrant to
search for evidence of Ganias’s tax evasion. This case fits squarely within Leon so
that, assuming, arguendo, that a Fourth Amendment violation occurred,
suppression was not warranted.

demanded to be returned clearly resolves a question about retention of a physical digital
storage medium (the return of which had been neither suggested nor requested) would
be “like saying a ride on horseback is materially indistinguishable from a flight to the
moon.” Riley, 134 S. Ct. at 2488.

60

 Case 12-240, Document 219, 05/27/2016, 1781342, Page61 of 61

*

*

*

We conclude that the Government relied in good faith on the 2006 search
warrant and thus AFFIRM the judgment of the district court.

Given this

determination, we do not reach the specific Fourth Amendment question posed
to us today.

61