14‐1083‐cr
United States v. Thomas
In the
United States Court of Appeals
for the Second Circuit
AUGUST TERM 2014
No. 14‐1083‐cr
UNITED STATES OF AMERICA,
Appellee,
v.
DEREK THOMAS,
Defendant‐Appellant.
On Appeal from the United States District Court
for the District of Vermont
ARGUED: JANUARY 15, 2015
DECIDED: JUNE 11, 2015
Before: WINTER, CABRANES, and RAGGI, Circuit Judges.
1
The question presented is whether a search warrant affidavit
that relied upon evidence generated by an automated software
program provided a substantial basis for a magistrate judge’s
conclusion that there was probable cause that child pornography
would be found on defendant’s computer.
We hold that the affidavit at issue sufficiently established
probable cause and that defendant’s motions to suppress were
properly denied.
The judgment of the United States District Court for the
District of Vermont (Christina Reiss, Chief Judge) is affirmed.
ELIZABETH D. MANN, Tepper Dardeck
Levins & Mann, LLP, Rutland, VT, for
Defendant‐Appellant.
NANCY J. CRESWELL (Paul J. Van De Graaf,
on the brief), Assistant United States
Attorneys, for Eugenia A.P. Cowles, Acting
United States Attorney for the District of
Vermont, Burlington, VT, for Appellee.
2
JOSÉ A. CABRANES, Circuit Judge:
The question presented is whether a search warrant affidavit
that relied upon evidence generated by an automated software
program provided a substantial basis for a magistrate judge’s
conclusion that there was probable cause that child pornography
would be found on defendant’s computer.
We hold that the affidavit at issue sufficiently established
probable cause and that defendant’s motions to suppress were
properly denied.
The judgment of the United States District Court for the
District of Vermont (Christina Reiss, Chief Judge) is affirmed.
BACKGROUND
Defendant Derek Thomas appeals from the denial of his
motions to suppress the searches of his residence and his computer.
Thomas pleaded guilty to the production of child pornography, in
violation of 18 U.S.C. § 2251(a),1 but reserved the right to appeal
1 Thomas pleaded guilty to the following statute:
Any person who employs, uses, persuades,
induces, entices, or coerces any minor to engage in,
or who has a minor assist any other person to
engage in, or who transports any minor in or
affecting interstate or foreign commerce, or in any
Territory or Possession of the United States, with
the intent that such minor engage in, any sexually
explicit conduct for the purpose of producing any
3
from two orders of the District Court for the District of Vermont
(Christina Reiss, Chief Judge) denying his motions to suppress
evidence. On March 31, 2014, the District Court sentenced Thomas
principally to 180 months’ imprisonment and 8 years’ supervised
release.
Thomas was arrested as part of a joint federal and state law
enforcement investigation in Vermont during 2011 and 2012, known
as “Operation Greenwave,” into potential child pornography
offenses committed through the use of peer‐to‐peer (“P2P”) file‐
sharing software.2 As part of the investigation, law enforcement
visual depiction of such conduct or for the purpose
of transmitting a live visual depiction of such
conduct, shall be punished as provided under
subsection (e), if such person knows or has reason
to know that such visual depiction will be
transported or transmitted using any means or
facility of interstate or foreign commerce or in or
affecting interstate or foreign commerce or mailed,
if that visual depiction was produced or
transmitted using materials that have been mailed,
shipped, or transported in or affecting interstate or
foreign commerce by any means, including by
computer, or if such visual depiction has actually
been transported or transmitted using any means
or facility of interstate or foreign commerce or in or
affecting interstate or foreign commerce or mailed.
18 U.S.C § 2251(a).
2 P2P file‐sharing is a means of exchanging files (i.e., photos, videos,
songs) with other Internet‐connected computer users who are also using file‐
sharing software. The P2P software is generally publicly available for download
4
relied upon automated software programs to help locate Internet
Protocol (“IP”) addresses engaged in the possession and distribution
of child pornography.3 The software, designed for and used by law
enforcement, was created by a private “data fusion” company called
TLO. United States v. Thomas, No. 5:12‐cr‐37, 2013 WL 6000484, at *4
(D. Vt. Nov. 8, 2013). TLO provides a suite of software and other
products—known collectively as the Child Protection System
(“CPS”)—to licensed law enforcement professionals free of charge to
investigate child pornography that is collected and distributed over
P2P networks. Id.
Traditionally, law enforcement officers seek to detect child
pornography offenses by manually sending out search queries for
illicit material over P2P networks, one‐by‐one. CPS automates this
process by canvassing these public P2P networks, identifying files
that contain child pornography, cataloguing this information, and
providing law enforcement officers with a list of the online users
who are sharing these files over P2P networks.4 Law enforcement
officers can then use that list to focus their investigative efforts on
from the Internet and operates on a particular network. See United States v.
Thomas, No. 5:12‐cr‐37, 2013 WL 6000484, at *2‐3 (D. Vt. Nov. 8, 2013).
3 An IP address is a numerical identifier assigned to a particular Internet
connection used by one or more computer devices.
4 For more information on the various types of CPS products, their
functionality, and their testing, see Thomas, 2013 WL 6000484, at *4‐6. See also
United States v. Dodson, 960 F. Supp. 2d 689, 692‐93 (W.D. Tex. 2013) (denying a
similar motion to suppress).
5
those IP addresses—and the associated computers and users—that
are believed to be engaging in the possession or distribution of child
pornography. Id.
In order to use CPS products, law enforcement must attend
and successfully complete a three‐day training course. During the
course, law enforcement officers are instructed on how to search for
child pornography with P2P file‐sharing software using both the
manual method and the automated CPS method. The officers are
then taught how to compare the results, to demonstrate the
reliability of the software. Id. If a law enforcement officer completes
the course, TLO will allow that officer to use the CPS software in his
or her jurisdiction. Id.
In late 2011, Detective Gerard Eno of the South Burlington
Police Department was investigating child exploitation offenses. The
particular focus of his investigation was offenders who were using
P2P file‐sharing software to exchange child pornography files. Id. at
*7, 11. Detective Eno, who had completed TLO’s training course and
was licensed by the company to operate its software in Vermont,
used CPS to identify an IP address that had offered to share images
and video files that were tagged as being potentially child
pornography. Detective Eno confirmed that the files indeed
6
constituted child pornography by cross‐referencing them with other
databases and file‐share systems.5 Id. at *11.
Using the IP address obtained through CPS, Detective Eno
traced the computer to a physical address in Vermont, which turned
out to be where defendant Derek Thomas lived. Special App. 41.
After conducting a period of surveillance on this residence, a search
warrant application for the address was submitted to a magistrate
judge. Accompanying the application was a 22‐page affidavit by
Homeland Security Investigations Special Agent Seth Fiore (the
“Fiore Affidavit”), which included a detailed explanation of: (1) P2P
file‐sharing; (2) how P2P file‐sharing software is used to exchange
child pornography; (3) the use made, in general, of CPS software
during the investigation; and (4) the grounds for probable cause to
search the target address and any computers found there (including
a description of the files that the CPS software detected on
defendant’s computer). Id. at 56‐82. While the Fiore Affidavit
described the use of CPS software in general terms, it did not
identify the company that created the software, or refer to the
software by name. Id. at 14‐15.
5 Detective Eno did not attempt to directly download the files from the IP
address but, instead, relied upon “historical” information to establish that they
constituted child pornography. Specifically, Detective Eno compared the hash
values—or the “digital fingerprints”—of the defendant’s files with the hash
values of images known to be child pornography that had previously been
downloaded from the Internet by law enforcement. Using this base of
comparison, he was able to establish that the defendant’s files were child
pornography for the purpose of the affidavit. Thomas, 2013 WL 6000484, at *3, 7.
7
The magistrate judge issued the requested search warrant. Id.
at 42. Law enforcement agents executed a search on the residence
and on Thomas’s computer. Id. at 42‐43. Child pornography files
were thereafter found on the computer. Id. at 43.
Thomas filed four separate motions to suppress the evidence
seized pursuant to these searches. Following a consolidated
suppression and Franks hearing,6 the District Court denied Thomas’s
motions, concluding that probable cause existed for the search of
Thomas’s residence and computer.
Relevant here, the District Court found that the Fiore Affidavit
adequately disclosed the fact that law enforcement used automated
software in conducting its investigations and that Thomas’s
challenge to the reliability of the automated software was
unsupported by any evidence. The District Court also found that the
6 It bears recalling that the purpose of a Franks hearing is for a defendant
to demonstrate that statements in an affidavit intentionally or recklessly misled a
district court. In Franks v. Delaware, 438 U.S. 154 (1978), the Supreme Court ruled
that while a presumption of validity attaches to a law enforcement affidavit, in
certain circumstances a defendant is entitled to a hearing in order to test the
veracity of an affiant’s statements. Id. at 171. To suppress evidence obtained
pursuant to an affidavit containing erroneous information, a defendant is
required to show that: “(1) the claimed inaccuracies or omissions are the result of
the affiant’s deliberate falsehood or reckless disregard for the truth; and (2) the
alleged falsehoods or omissions were necessary to the issuing judge’s probable
cause or necessity finding.” United States v. Rajaratnam, 719 F.3d 139, 146 (2d Cir.
2013) (quoting United States v. Canfield, 212 F.3d 713, 717‐18 (2d Cir. 2000))
(internal quotation marks and brackets omitted).
8
primary function of CPS is simply to produce lists of otherwise
public information.
DISCUSSION
The question before us is whether, under the totality of the
circumstances, the Fiore Affidavit provided a substantial basis for
the magistrate judge’s conclusion that there was probable cause that
child pornography would be found on a computer in Thomas’s
residence.
The standard of review for evaluating the district court’s
ruling on a suppression motion is clear error as to the district court’s
findings of historical facts, but de novo as to ultimate legal
conclusions, such as the existence of probable cause. United States v.
Raymonda, 780 F.3d 105, 113 (2d Cir. 2015).
Probable cause “is a fluid concept—turning on the assessment
of probabilities in particular factual contexts—not readily, or even
usefully, reduced to a neat set of legal rules.” Maryland v. Pringle, 540
U.S. 366, 370‐71 (2003) (citation omitted). Indeed, the probable‐cause
standard is “incapable of precise definition or quantification into
percentages because it deals with probabilities and depends on the
totality of the circumstances.” Id. at 371.
When reviewing a challenged warrant, we “accord
considerable deference to the probable cause determination of the
issuing magistrate.” Walczyk v. Rio, 496 F.3d 139, 157 (2d Cir. 2007).
This degree of deference derives from a concern that “[a] grudging
9
or negative attitude by reviewing courts toward warrants will tend
to discourage police officers from submitting their evidence to a
judicial officer before acting.” United States v. Ventresca, 380 U.S. 102,
108 (1965). Accordingly, the task of a reviewing court is simply to
ensure that the totality of the circumstances afforded the magistrate
“a substantial basis” for making the requisite probable cause
determination. Illinois v. Gates, 462 U.S. 213, 238 (1983).
We have previously held that “to suppress evidence obtained
pursuant to an affidavit containing erroneous information, the
defendant must show that: (1) the claimed inaccuracies or omissions
are the result of the affiant’s deliberate falsehood or reckless
disregard for the truth; and (2) the alleged falsehoods or omissions
were necessary to the issuing judge’s probable cause or necessity
finding.” United States v. Rajaratnam, 719 F.3d 139, 146 (2d Cir. 2013)
(quoting United States v. Canfield, 212 F.3d 713, 717–18 (2d Cir. 2000))
(internal quotation marks and brackets omitted). In the case of
omissions, we explained that “the ultimate inquiry is whether, after
putting aside erroneous information and correcting material
omissions, there remains a residue of independent and lawful
information sufficient to support a finding of probable cause or
necessity.” Id. (quoting Canfield, 212 F.3d at 718) (internal quotation
marks and brackets omitted). In general, it is strong evidence that
the Government did not deliberately falsify information in the
affidavit, or act with “reckless disregard for the truth,” when the
alleged omission would have strengthened, rather than weakened,
the Government’s showing of probable cause. See id. at 155.
10
Here, Thomas asserts that the evidence recovered from his
computer must be suppressed because the Government omitted two
crucial items of information from the affidavit that the magistrate
relied upon in issuing the relevant search warrants: (1) the fact that
CPS, a third‐party software source, generated the information upon
which the Government relied; and (2) information regarding the
reliability of the CPS software.7
I. Disclosure of CPS in the Affidavit
Thomas asserts that the Fiore Affidavit did not adequately
disclose or describe the use of CPS to generate the evidence that the
Government relied upon in its warrant application.
Thomas’s disclosure claim can be divided into two separate,
but related, challenges: (1) that the Fiore Affidavit failed to disclose
the third‐party nature of CPS, see Appellant’s Br. 28; and (2) that the
Fiore Affidavit failed to disclose the commercial name of CPS, id. at
36.
Thomas also argues that the warrant, if valid, did not authorize the
7
search of his computer because he was an “unanticipated guest” in the home
where the search occurred. This contention is baseless—as the agents confirmed
before seizing Thomas’s computer, the defendant had been staying at the
address listed on the affidavit for 10 months. See Gov’t App. 13. Nonetheless,
defendant advances a novel interpretation of the Fourth Amendment that would
require law enforcement to obtain an additional “warrant to search a specific
computer device” within an otherwise searchable area. Appellant’s Br. 19. For
substantially the reasons stated by the District Court, see Special App. 43‐46, we
decline to adopt such a requirement.
11
Both challenges are without merit. The fact that the software
was created by a third‐party is immaterial here. The software, as
explained below, merely aggregates existing public information, and
so its provenance has no bearing on the probable cause
determination. Indeed, defendant presents no case law or other
authority for his assertion that law enforcement was required to
explicitly state the non‐governmental nature of the software’s
creator. In any case, the District Court concluded that the affidavit at
issue did adequately disclose “the use of third party software to
identify the IP address of a target computer and to monitor and log
Internet and local network traffic from that IP address.” Thomas,
2013 WL 6000484, at *8.
In the same vein, Thomas provides no case law or other
authority to support his argument that the Government was
required to disclose the commercial name of the software used to
uncover evidence of his crime. We have never held that the
anonymity of a source of information destroys the veracity of an
affidavit, especially where the source is known, disclosed, and
described, with only its name withheld.8 Rather, when the Supreme
Court, in Illinois v. Gates, 462 U.S. at 238, “reaffirm[ed] the totality‐of‐
the‐circumstances analysis” for probable cause determinations, it
also reaffirmed the value of “anonymous citizen informants” and
the need for a “common‐sense” approach to assessing the “veracity”
8 See, e.g., United States v. Smith, 9 F.3d 1007, 1013 (2d Cir. 1993) (finding
“it [ ] certainly not fatal” when an affidavit is based on an anonymous
informant’s statements which the Agent “did not personally witness”).
12
and “basis of knowledge” of those informants. Id. Requiring the
Government to name the third‐party software vendor in the
affidavit—in addition to the detailed description of the software—
would run counter to the general reasoning of Illinois v. Gates.
Moreover, just as an informant’s name can be presented
anonymously in an affidavit, see id., so too can a company’s name.
Probable cause determinations can hang solely on the veracity of an
informant, but not on that informant’s name. So too, the primary
relevance of automating third‐party software lies not in its name,
but in its functionality.9 And in this case, the functionality of the
software—and all of the material facts relating to law enforcement’s
reliance on it—were clearly described in the affidavit. Specifically,
the affidavit disclosed that law enforcement used automated
software during the course of this investigation, noted the software’s
purpose, and then went into considerable detail as to how the
software operated. No additional or more specific information was
necessary.
Finally, we cannot conclude that any omission here was made
deliberately or with “reckless disregard for the truth” when it is
clear that full disclosure of the relevant information would only
have strengthened the search warrant application. Rajaratnam, 719
9 There may be situations where the Government has reason to believe
that facts beyond the software’s functionality (e.g., a company’s notorious
reputation for unreliability) bear on the probable cause analysis. In such a case,
not disclosing the company’s name in a search warrant affidavit could arguably
be considered a material omission relevant to probable cause.
13
F.3d at 155. In fact, during the proceedings in the District Court,
Thomas conceded that if the affidavit had contained more detailed
information it would have strengthened, not weakened, the
Government’s case for probable cause. J.A. 546‐47.
II. Reliability of CPS
Thomas also asserts that the affidavit failed to establish the
reliability of the CPS software at issue, drawing a parallel to the
drug‐sniffing dog in Florida v. Harris, 133 S. Ct. 1050 (2013). There,
the Supreme Court held that a drug‐sniffing dog’s satisfactory
performance in a certification or training program is a sufficient
basis to trust his alert and thus establish probable cause. Thomas
contends that no such certification or testing was done on the CPS
software, thereby calling into question the subsequent probable
cause determination generated by law enforcement’s use of CPS.
Thomas’ reliability challenge fails for several reasons. First, his
analogy to a drug‐sniffing dog is inapposite. Employing a drug‐
sniffing dog to establish probable cause involves numerous steps,
each of which is susceptible to error: (1) the training of the dog to
identify illicit substances; (2) the dog’s ability to follow its training in
identifying a particular illicit substance; (3) the dog appropriately
signaling to law enforcement that an illicit substance is present; and
(4) a law enforcement agent’s ability to properly interpret that
signal. Moreover, any such error along this chain is not always
14
discernible to law enforcement, as dogs contain certain sensory
abilities that are far superior to those of humans.10
By contrast, the CPS software merely automates the
aggregation of public information—a task that could otherwise be
performed manually by law enforcement, albeit at a slower and less
efficient pace.11 Moreover, as the District Court found, the CPS
software is built directly on the source code (i.e., the digital skeleton)
10 See, e.g, Florida v. Harris, 133 S. Ct. at 1056 (noting that law enforcement
may not be able to discern whether a canine actually erred if the dog signaled
illegality to law enforcement after detecting illegal substances that were well‐
hidden, present in small quantity, or present only in some residual form).
11 See Thomas, 2013 WL 6000484, at *6 (“[CPS products] are evidence‐
gathering tools that merely obtain, report, and categorize information regarding
files that are available for sharing from a particular IP address. A law
enforcement officer must then take further steps to determine whether the
information received supports a conclusion that there is probable cause to
believe that evidence of child pornography will be found at a particular physical
address.”); see also United States v. Naylor, No. Crim. A. 2:14‐194, 2015 WL 730078,
at *4 (S.D. W. Va. Feb. 19, 2015) (“[T]he CPS program works by listening over,
and performing searches on, Internet networks. In doing so, it attempts to find
those users offering, or desiring, results associated with child exploitation.”);
United States v. Dennis, No. 3:13‐cr‐10‐TCB, 2014 WL 1908734, at *2 (N.D. Ga. May
12, 2014) (“[CPS] collects publicly available information.”); Dodson, 960 F. Supp.
2d at 692 (“To root out purveyors of child pornography on these P2P networks,
law enforcement agencies have developed specialized software to troll public
networks, identify files containing child pornography, locate the users sharing
these files, and catalog all of this public information. One example of this type of
software is the Child Protection System (CPS).”).
15
of the file‐sharing programs and so, unlike a sniffing dog, the risk of
error, if any, is drastically reduced.12
A hypothetical question is illuminating—would the probable
cause calculus be different if a police officer witnessed a drug deal or
if a pre‐positioned CCTV camera was able to capture that same
transaction? Clearly not. Similarly, the probable cause calculus
should be the same here, regardless of whether the CPS software
detected Thomas’s sharing of child pornography by automatically
collecting and assessing public traffic over a P2P network, or
whether Detective Eno witnessed the sharing of those same illicit
files on a P2P network in real time.
In any case, we discern no error—much less, clear error—in
the District Court’s finding that CPS was a reliable tool that could
serve as the basis of a search warrant affidavit.13 The District Court
found that there was no evidence “that CPS products report false or
misleading information,” nor was there any evidence presented
demonstrating that CPS was not reliable. Thomas, 2013 WL 6000484,
at *6. Finally, the District Court also found that there are no
12 The District Court concluded that, because CPS is based upon the same
protocol used by the file‐sharing network, it is not clear what, if any, adjustments
could be made to render the software more reliable. See Thomas, 2013 WL
6000484, at *6.
13 See also, e.g., Naylor, 2015 WL 730078, at *5 (“The CPS software appears
to be a reliable investigative tool for law enforcement in [child pornography]
cases.”).
16
industry‐accepted tests or methodology that could have been used
to further enhance the reliability of CPS software.14 Id.
Based upon an examination of the totality of the
circumstances, there existed sufficient “indicia of reliability” to
permit a reasonable person to conclude that probable cause existed
in these circumstances. Illinois v. Gates, 462 U.S at 233. Law
enforcement verified and corroborated the information received
from CPS through a hash‐value analysis,15 and cogently made the
case in their affidavit such that a reasonably prudent person,
viewing the evidence “through the lens of common sense . . . would
. . . think that a search would reveal contraband or evidence of a
crime.” Florida v. Harris, 133 S. Ct. at 1058.
14 An affidavit relying upon CPS software was similarly challenged in an
Ohio child pornography case, Mahan v. Bunting, No. 1:13‐CV‐165, 2014 WL
1153444 (N.D. Ohio Feb. 3, 2014), report and recommendation adopted as modified,
2014 WL 1154054 (N.D. Ohio Mar. 20, 2014). The Mahan Court also held that a
warrant predicated on information obtained from automated P2P software was
sufficient to establish probable cause. As that court put the point, “[d]efendant
has not provided us with a single authority, in Ohio or otherwise, that found
suppression was warranted where law enforcement obtained a search warrant
based on the use of technology that searches open peer‐to‐peer networks.” 2014
WL 1153444, at *10.
15 See supra n.4 and accompanying text.
17
CONCLUSION
We hold that probable cause was sufficiently established in
the affidavit at issue and that Thomas’s motions to suppress were
thus properly denied.
For the reasons set forth above, we AFFIRM the District
Court’s March 31, 2014, judgment.
18