United States Court of Appeals
                            FOR THE EIGHTH CIRCUIT
                                  ___________

                                  No. 08-2799
                                  ___________

United States of America,              *
                                       *
            Appellee,                  *
                                       * Appeal from the United States
      v.                               * District Court for the Eastern
                                       * District of Missouri.
Roderick McArthur,                     *
                                       *
            Appellant.                 *
                                  ___________

                             Submitted: February 10, 2009
                                Filed: July 27, 2009
                                 ___________

Before RILEY, SMITH, and SHEPHERD, Circuit Judges.
                             ___________

SHEPHERD, Circuit Judge.

      On November 1, 2007, Roderick McArthur was indicted on one count of
possession of child pornography, in violation of 18 U.S.C. § 2252A(a)(5)(B) and
2252A(b)(2). McArthur filed a motion to suppress evidence, and an evidentiary
hearing was held before a federal magistrate judge.1 On January 25, 2008, the
magistrate judge issued a Report and Recommendation (“R&R”) recommending
denial of the motion to suppress. McArthur did not file any objections to the R&R.



      1
       The Honorable Mary Ann L. Medler, United States Magistrate Judge for the
Eastern District of Missouri.
On February 19, 2008, the district court2 adopted the R&R and denied the motion to
suppress. McArthur waived his right to a jury trial. On April 2, 2008, following a
bench trial, the district court found McArthur guilty as charged. The district court
sentenced McArthur to 151 months imprisonment and supervised release for life.
McArthur appeals the court’s denial of his motion to suppress, as well as the denial
of his motion for judgment of acquittal, which he made at the close of the
government’s case and renewed at the trial’s conclusion. For the reasons set forth
below, we affirm.

                                          I.

       On April 1, 2006, Officer Trent Koppel of the Des Peres Police Department was
on patrol at the West County Mall in Des Peres, Missouri, when mall security reported
that an older, white male was masturbating inside his vehicle in the mall parking lot.
Officer Koppel responded immediately, located the vehicle, and activated her
emergency lights. The driver attempted to navigate around the cars in front of him but
was unsuccessful. Officer Koppel approached the blocked-in vehicle and ordered the
driver to turn off the engine and exit the vehicle. Officer Koppel observed that the
driver’s penis was exposed. The driver exited the vehicle and handed Officer Koppel
his driver’s license, which identified the driver as Roderick McArthur. Officer
Koppel placed McArthur under arrest for public indecency and transported him to the
Des Peres Police Department for booking.

      Officers inventoried McArthur’s personal property and found in his wallet a
laminated photograph of a nude, male child who is looking at and touching an erect,
adult penis that is superimposed on the child’s body. Officer Koppel advised




      2
        The Honorable Donald J. Stohr, United States District Judge for the Eastern
District of Missouri.

                                         -2-
McArthur of his Miranda rights,3 which McArthur waived. McArthur stated that he
has always had an overactive libido and sometimes could not control his urges. He
claimed that he met someone online who agreed to meet him at the West County Mall.
When that person did not arrive, McArthur stated that he drove around the parking lot,
became aroused, and began to masturbate. In a written statement, McArthur admitted
exposing himself in the vehicle and apologized for his “very inappropriate behavior.”
McArthur posted bond and was released on the same day as his arrest.

       Officer Koppel contacted Detective Juan Gomez, then a nine-year veteran of
the St. Louis County Police Department with extensive training and experience
investigating child pornography offenses, and provided Detective Gomez with
information regarding McArthur’s arrest. Detective Gomez confirmed McArthur’s
home address by conducting a utilities check. Detective Gomez also discovered that
McArthur was convicted in 1986 for sodomy involving a minor and in 2004 for sexual
misconduct and that McArthur had failed to register as a sex offender. Another St.
Louis County officer, Sergeant Adam Kavanaugh, procured the nude photograph
found in McArthur’s wallet from the Des Peres Police Department. Sergeant
Kavanaugh showed the photograph to Detective John Schmidt, a forensic analyst in
the Computer Fraud Unit. Detective Schmidt stated that the photograph had been
modified using computer software.

       On April 4, 2006, Detective Gomez applied for a search warrant for McArthur’s
residence and any digital data devices found therein for evidence of possession of
child pornography. Detective Gomez presented an affidavit in support of the
application to the Honorable Brenda Stith Loftin, Associate Circuit Judge for the St.
Louis County Circuit Court. The affidavit described the property to be searched with
particularity, listed Detective Gomez’s experience with “subjects known to possess
and sell obscene material,” detailed the events surrounding McArthur’s public


      3
       See Miranda v. Arizona, 

 (1966).

                                         -3-
indecency arrest (including the discovery of the computer-altered photograph), and
stated that “McArthur has been arrested for multiple sex offenses in St. Louis County,
Missouri[,] in the past twenty years but has failed to register as a sex offender as
required by law.”

       Judge Loftin authorized the search warrant at 6:30 p.m. on April 4, 2006.
Officers executed the warrant later that evening and seized several digital data devices
from McArthur’s residence, including a computer. Detective Gomez then arrested
McArthur, who was present during the search, for failing to register as a sex offender
and escorted him to the St. Louis County Police Department. Detective Gomez
interviewed McArthur, who again waived his Miranda rights. When asked about the
photograph found in his wallet when he was arrested in Des Peres, McArthur claimed
that his nephew had given the photograph to him 15 to 20 years earlier and that he had
placed it in his wallet and forgotten about it. Detective Gomez asked McArthur for
consent to search his computer and the other devices. After repeatedly and
emphatically denying that there was child pornography on any of his equipment,
McArthur consented, in writing, to the search.

      Detective Gomez took the seized items to the Regional Computer Crime
Education and Enforcement Group (“RCCEEG”) to be examined by Detective
Leonard Stimmel, a forensic computer analyst. During a brief examination of the
computer, Detective Stimmel discovered several images of children involved in sex
acts or displaying their genitals in a sexual manner. Even though McArthur had
already consented in writing to the search of his computer, out of an abundance of
caution, Detective Gomez presented another application and affidavit in support of a
search warrant for the computer. In addition to reiterating all of the information
contained in the first affidavit, the new affidavit detailed the seizure of the computer
and the results of Detective Stimmel’s brief search of its contents. The Honorable
Dale W. Hood, Associate Circuit Judge for the St. Louis County Circuit Court, found
probable cause and signed the search warrant for McArthur’s computer.

                                          -4-
       Detective Kenneth Nix, a computer forensic examiner and the operations
supervisor of the RCCEEG, thoroughly examined the hard drive from McArthur’s
computer. Detective Nix located multiple images in the hard drive’s unallocated
space4 that depicted children displaying their genitals and engaging in masturbation,
oral sex, and vaginal sex with adults. Also in the unallocated space, Detective Nix
found myriad child pornography web pages that the user had visited directly.
Detective Nix’s examination showed that someone had reinstalled the computer’s
operating system on April 2, 2006—the day after the Des Peres Police Department
released McArthur following his public indecency arrest and two days before the St.
Louis County Police Department executed the search warrant for McArthur’s home
and seized his computer. Detective Nix testified at trial that computers normally come
with an operating system already installed and that, when someone reinstalls the
operating system, all of the computer’s data is moved into unallocated space on the
hard drive. Finally, Detective Nix reviewed disks that McArthur’s expert witness,
Gregory Chatten, claimed to be back-up disks of some of the data on McArthur’s
computer over a three-year period prior to its seizure. One of the disks contained
authentication codes for several websites, including sites that contained child
pornography.

      Chatten confirmed that images of child pornography were located in the
unallocated space on McArthur’s hard drive. He also confirmed that reinstalling
McArthur’s operating system would have moved all of the computer’s data into
unallocated space. Chatten testified that he could not discern the source of the images.
However, he agreed that the user had directly visited some of the child pornography
websites found in unallocated space. Chatten further testified that one of McArthur’s
purported back-up disks was actually created on October 5, 2007, the same day the

      4
       Detective Nix testified that “allocated space” is space on a computer that is
usable. When a user deletes a file, it is not erased completely from the computer.
Instead, the deleted file is moved to “unallocated space,” which is where Detective
Nix located child pornography on McArthur’s computer.

                                          -5-
disks were mailed to McArthur’s attorney and more than a year after police seized
McArthur’s computer. Chatten agreed that it was possible that a person could have
copied an actual back-up disk made in 2005 to this new disk and then deleted files that
the person did not wish Chatten to see. Chatten testified that he could not determine
whether any files had been deleted from the purported back-up disk that was actually
created on October 5, 2007.

       On appeal, McArthur argues that the district court erred in adopting the R&R
recommending denial of his motion to suppress because there was not probable cause
to believe that there was evidence of child pornography in his home. Thus, McArthur
contends, all of the fruits of that initial search, including the cursory examination of
the computer and the images discovered as a result of McArthur’s subsequent written
consent, should have been suppressed. McArthur further argues that the district court
erred in denying his motion for judgment of acquittal because the mere presence of
child pornography images and websites stored in the computer’s unallocated space is
insufficient to prove that McArthur knowingly possessed child pornography.

                                           II.

      McArthur contends that the district court erred in denying his motion to
suppress because there was not probable cause to believe that child pornography
would be found in his home. “Ordinarily, when reviewing a district court’s denial of
a suppression motion, we review for clear error the court’s factual findings and review
de novo whether the Fourth Amendment was violated.” United States v. Rodriguez,

, 1010 (8th Cir.), cert. denied, 

 (2007). However, because
McArthur failed to object to the magistrate judge’s R&R, he “waived his right to de
novo review by the district court of any portion of the [R&R] of the magistrate judge
as well as his right to appeal from the findings of fact contained therein.” Id. at 1010-
11 (quoting United States v. Newton, 

, 966 (8th Cir. 2001)). “Thus, ‘we



                                           -6-
review the court’s factual determinations for plain error.’” Id. at 1011 (quoting United
States v. Brooks, 

, 1105 (8th Cir. 2002)).

       “Our role is to ensure that the evidence as a whole provides a substantial basis
for finding probable cause to support the issuance of the search warrant” for
McArthur’s residence. United States v. Terry, 

, 822 (8th Cir. 2002).
“Whether probable cause . . . has been established is determined by considering the
totality of the circumstances, and resolution of the question by an issuing judge
‘should be paid great deference by reviewing courts.’” United States v. Grant, 

, 631 (8th Cir. 2007), cert. denied, 

 (2008) (quoting Illinois
v. Gates, 

, 236 (1983)). “When the affidavit supporting the search
warrant sets forth facts sufficient to create a fair probability that evidence of a crime
will be found in the place to be searched, probable cause exists.” Terry, 305 F.3d at
822. “Accordingly, we examine the sufficiency of a search-warrant affidavit using a
‘common sense’ and not a ‘hypertechnical’ approach.” Grant, 490 F.3d at 632
(quoting United States v. Solomon, 

, 827 (8th Cir. 2005)).

        McArthur does not challenge any factual determinations made below. He
argues that the affidavit Detective Gomez filed in support of the application for the
initial search warrant for McArthur’s residence “contained insufficient indicia of
probable cause to believe that McArthur possessed child pornography, in his home or
on his computer.” (Appellant’s Br. 22.) Specifically, McArthur asserts that “the only
averment even remotely connected to child pornography was a single laminated
photograph in McArthur’s wallet . . . .” (Id.) Thus, according to McArthur, “the
inference that [he] kept child pornography in his home or on his computer was
specious” and insufficient to support probable cause. (Id.) We disagree.

      The affidavit chronicled the circumstances surrounding McArthur’s public-
indecency arrest for masturbating in his car in a mall parking lot three days earlier.
Most significantly, the affidavit noted that, at the time of his arrest, McArthur

                                           -7-
possessed a laminated photograph of a nude child that had been modified using
computer software. This revelation, standing alone, strongly indicated that child
pornography would be found on McArthur’s computer. Furthermore, the affidavit
revealed that McArthur had been convicted for multiple, prior sex offenses but had
failed to register as a sex offender and that Detective Gomez had experience dealing
with subjects known to possess and sell obscene material. Finally, other courts have
recognized—and Detective Gomez testified at the suppression hearing—that

      [t]he observation that images of child pornography are likely to be
      hoarded by persons interested in those materials in the privacy of their
      homes is supported by common sense and the cases. Since the materials
      are illegal to distribute and possess, initial collection is difficult. Having
      succeeded in obtaining images, collectors are unlikely to [] destroy them.
      Because of their illegality and the imprimatur of severe social stigma
      such images carry, collectors will want to secret them in secure places,
      like a private residence.

United States v. Riccardi, 

, 861 (10th Cir. 2005) (quoting United States
v. Lamb, 

, 460 (N.D.N.Y. 1996)).

      Considering the “totality of the circumstances” and examining the affidavit
using a “common sense” approach, Grant, 490 F.3d at 631-32, we find that “the
evidence as a whole provide[d] a substantial basis for finding probable cause to
support the issuance of the search warrant” for McArthur’s residence because “the
affidavit supporting the search warrant set[] forth facts sufficient to create a fair
probability that evidence of [possession of child pornography would] be found,”
Terry, 305 F.3d at 822. Therefore, the district court did not err when it denied
McArthur’s motion to suppress.5


      5
       “Because we find that probable cause existed to support the search warrant, we
need not address [McArthur’s] additional argument that the ‘good faith’ exception to
the exclusionary rule does not apply.” United States v. Caswell, 

, 900

                                           -8-
                                           III.

      McArthur also contends the district court erred in denying his motion for
judgment of acquittal because the evidence was insufficient to support a guilty verdict.
“When reviewing the sufficiency of the evidence after a bench trial, we view the
evidence in the light most favorable to the verdict and uphold the verdict if a
reasonable factfinder could find the offense proved beyond a reasonable doubt.”
United States v. Zackery, 

, 649 (8th Cir. 2007), cert. denied, 

 (2008). “A [] verdict may be based on circumstantial as well as direct evidence,
and [t]he evidence need not exclude every reasonable hypothesis except guilt.”
United States v. Ellefson, 

, 863 (8th Cir. 2005) (quotation omitted).
Indeed, “[i]f the evidence rationally supports two conflicting hypotheses, the
reviewing court will not disturb the conviction.” United States v. Chipps, 

, 964 (8th Cir. 2002) (quotation omitted).

       McArthur argues that, based on the evidence presented at trial, no reasonable
factfinder could find beyond a reasonable doubt that he knowingly possessed child
pornography. McArthur emphasizes the fact that all of the images and websites
containing child pornography were found in “unallocated space” on his hard drive.
He also highlights trial testimony explaining “that a computer’s browser cache
contains images automatically saved . . . when a website is visited, and those images
may be beyond the scope of what the user requested.” (Appellant’s Br. 32-33.)
McArthur hypothesizes that images and websites containing child pornography “could
have been reposited or deposited on the hard drive by virtue of McArthur visiting
[legal] adult websites and then reinstalling his operating system[] to cure a virus or for
another innocuous reason . . . .” (Id. at 31-32.) However, McArthur expressly
acknowledges the possibility of a conflicting hypothesis—that he “could have
downloaded the images himself onto the computer and transferred them to unallocated


n.3 (8th Cir. 2006).

                                           -9-
space when he reinstalled the operating system . . . .” (Id. at 33.) This
acknowledgment clearly demonstrates that the evidence in this case “rationally
supports two conflicting hypotheses.” Chipps, 299 F.3d at 964. Therefore, we “will
not disturb [McArthur’s] conviction.” Id.

                                       IV.

      Accordingly, we affirm the judgment of the district court.
                     ______________________________




                                       -10-