United States Court of Appeals
                            FOR THE EIGHTH CIRCUIT
                                  ___________

                                  No. 09-1408
                                  ___________

United States of America,              *
                                       *
            Appellee,                  *
                                       * Appeal from the United States
      v.                               * District Court for the
                                       * District of Minnesota.
Aaron Jay Montgomery Lemon,            *
                                       *
            Appellant.                 *
                                  ___________

                             Submitted: November 20, 2009
                                Filed: January 7, 2010
                                 ___________

Before WOLLMAN, JOHN R. GIBSON, and SHEPHERD, Circuit Judges.
                          ___________

WOLLMAN, Circuit Judge.

       Aaron Jay Montgomery Lemon conditionally pleaded guilty to production of
child pornography, in violation of 18 U.S.C. § 2251(a), and was sentenced to 240
months’ imprisonment. He appeals, arguing that the district court1 erred in denying
his motion to suppress evidence because the search warrant was based on stale
information and thus not supported by probable cause. We affirm.



      1
      The Honorable David S. Doty, United States District Judge for the District of
Minnesota, adopting the report and recommendation of the Honorable Susan Richard
Nelson, United States Magistrate Judge for the District of Minnesota.
                                          I.

       Law enforcement agents began investigating Lemon as a result of a separate
investigation in San Francisco, California. On June 26, 2007, FBI agents in San
Francisco executed a search warrant at the workplace of George Halldin, who was
suspected of distributing child pornography online. A forensic examination of
Halldin’s computer revealed more than 9,000 images of child pornography and chat
logs showing that Halldin had traded child pornography with another individual who
used the screen name b2003, later identified as Lemon.

       The chat logs revealed that the first interaction between Halldin and Lemon
occurred on November 4, 2006. Lemon initiated a conversation by asking Halldin,
“do u trade pics?” Halldin responded that he had pictures of preteens, and Lemon
asked “how yng?” Halldin replied that there was “no limit that way,” whereupon the
two men began exchanging pictures. The images that Lemon sent included depictions
of sexual acts with females appearing to be approximately five years of age. In a
subsequent chat that same day, Lemon stated that “i’ve got lots of boys,” and in a chat
that took place the following month, Lemon asked Halldin, “u got more baby boy?”
The FBI determined that Lemon chatted and exchanged child pornography with
Halldin on four occasions between November 4, 2006, and December 5, 2006.

       Based on the information from their investigation of Halldin, law enforcement
officers subpoenaed internet service providers and determined that the individual who
was using the b2003 screen name was located near Saint Paul, Minnesota. In April
2008, Sergeant William Haider of the Saint Paul Police Department assumed primary
responsibility for the investigation. He traced the IP address to Lemon’s apartment
and confirmed that the b2003 screen name was still active, registering login activity
on April 30, 2008.




                                         -2-
       In June 2008 Officer Haider sought a search warrant for Lemon’s apartment.
The warrant application included extensive discussion of Haider’s expertise in
investigating online distribution of child pornography. Haider acknowledged that the
exchange between Halldin and b2003 had occurred eighteen months earlier, but he
opined that a search of Lemon’s residence would likely result in discovery of child
pornography because b2003 had demonstrated behavior indicative of a preferential
collector. Haider stated that “[i]t is probable that this type of child pornography
collector will maintain child pornography images over an extended period of time as
[he] compulsively and systematically save[s] the collected material.” He further
explained that such an individual rarely destroys his collection and would likely
maintain child pornography on his computer hard drive for many years.

      Haider received a search warrant, and a subsequent search revealed substantial
evidence that Lemon had been engaged in production and distribution of child
pornography.

                                         II.

       On an appeal of a denial of a motion to suppress evidence, we review the
district court’s factual findings for clear error and its legal conclusions de novo.
United States v. Pruneda, 

, 603 (8th Cir. 2008).

       Lemon contends that the search warrant was not supported by probable cause
and that the evidence seized from his apartment should have been excluded.
“Probable cause means a ‘fair probability that contraband or evidence of a crime will
be found in a particular place,’ given the circumstances set forth in the affidavit.”
United States v. Horn, 

, 785 (8th Cir. 1999) (quoting Illinois v. Gates,

, 238 (1983)). The date of the evidence in the affidavit is important to
the probable cause determination because untimely information may be deemed stale.
United States v. Summage, 

, 1078 (8th Cir. 2007). Lemon argues that

                                         -3-
Officer Haider’s affidavit was inadequate to establish probable cause because it
alleged that Lemon had last traded child pornography in December 2006, eighteen
months before the warrant issued.

       “There is no bright-line test for determining when information in a warrant is
stale.” 

. Rather, we look to the circumstances of the case,
including the nature of the crime involved. 

of time is least important
when the suspected criminal activity is continuing in nature and when the property is
not likely to be destroyed or dissipated.” 

.

       We conclude that the information in the affidavit raised a fair probability that
a search of Lemon’s apartment would result in the discovery of child pornography.
Possession of child pornography is a crime that is continuing in nature, and the
evidence in the warrant application established that Lemon was unlikely to have
destroyed the illegal material. Although the last known exchange of child
pornography occurred in December 2006, Officer Haider cited evidence that the IP
address and b2003 screen name were used in April 2008. These facts supported the
inference that Lemon was still trading child pornography, particularly when coupled
with Officer Haider’s explanation that Lemon’s behavior in November and December
2006 was indicative of a preferential collector who would maintain his collection for
a long period of time.

       Lemon argues that Officer Haider’s assertion about the practices of pedophiles
was mere conjecture, unsupported by evidence. This contention is belied, however,
by both the warrant application and a large body of precedent. Officer Haider’s
affidavit provided significant detail about his qualifications and explained how his
years of experience supported his conclusions. He also cited specific portions of the
chat transcripts between Lemon and Halldin to demonstrate why he believed Lemon
was a preferential collector of chid pornography. Many courts, including our own,
have given substantial weight to testimony from qualified law enforcement agents

                                         -4-
about the extent to which pedophiles retain child pornography. See, e.g., United States
v. Chrobak, 

, 1046 (8th Cir. 2002); see also United States v. Morales-
Aldahondo, 

, 119 (1st Cir. 2008); United States v. Irving, 

,
125 (2d Cir. 2006); United States v. Riccardi, 

, 861 (10th Cir. 2005);
United States v. Lacy, 

, 746 (9th Cir. 1997).

        The eighteen-month interim between Lemon’s last interaction with Halldin and
the warrant application, though not insignificant, is hardly unprecedented. In United
States v. Maxim, 

, 397 (8th Cir. 1995), we upheld a warrant based in part
on three-year-old information about the defendant’s illegal possession of a firearm,
because the suspected offense was continuing in nature and because expert testimony
established that possessors of illegal firearms often keep their weapons for a long
period of time. Similarly, in Morales-Aldahondo, the First Circuit held that a three-
year lapse between the defendant’s purchase of child pornography and the warrant
application did not render the information 

. The court noted the
considerable evidence in the warrant application demonstrating that pedophiles do not
quickly dispose of child pornography, observing that “[t]his is not a new revelation.”
Id.; cf. United States v. Prideaux-Wentz, 

, 958-59 (7th Cir. 2008)
(holding the warrant invalid because the date of the evidence was uncertain and could
have been easily ascertained, but refusing to hold that evidence two to four years old
is stale as a matter of law).

       Lemon contends that United States v. Rugh, 

(8th Cir. 1992),
requires us to hold that the evidence supporting the warrant was stale. We disagree.
In Rugh, the defendant argued that the warrant was invalid because it was based on
evidence of child molestation and possession of child pornography sixteen months
before the warrant application. Although the district court found that the information
was stale, we did not reach the issue of staleness because the government failed to
challenge the district court’s finding on appeal. 

Instead, we affirmed the
district court’s conclusion that the search was covered by the good-faith exception to

                                         -5-
the exclusionary rule, holding that the police could have reasonably believed that the
defendant would still have child pornography in his home. 

Rugh did not,
as Lemon contends, establish that sixteen-month-old evidence of possession of child
pornography is stale as a matter of law. Indeed, in the seventeen years since we
decided Rugh, technological advances have increased the ease with which child
pornography may be produced, maintained, or distributed—making it all the more
likely that the contraband will be retained. See, e.g., United States v. Newsom, 

, 783 (7th Cir. 2005) (observing that increased computer storage capacity
may make it easier to retain child pornography for a significant period of time).

        The evidence in the warrant application established that Lemon was interested
in child pornography and that he had traded a significant amount of it on four
occasions in late 2006. That information, augmented by Officer Haider’s expert
testimony and evidence that the screen name and IP address were still in use, was
sufficient to create a fair probability that a search of Lemon’s apartment would yield
child pornography. Accordingly, the district court did not err in finding that the
warrant was supported by probable cause.

       The judgment is affirmed.
                      ______________________________




                                         -6-