July 30, 2015
The People of the State of Colorado, Plaintiff-Appellee,
Kenneth Froehler, Defendant-Appellant
and County of Denver District Court No. 09CR5412. Honorable
Anne M. Mansfield, Judge.
H. Coffman, Attorney General, John T. Lee, Assistant Attorney
General, Denver, Colorado, for Plaintiff-Appellee.
K. Wilson, Colorado State Public Defender, Chelsea E. Mowrer,
Deputy State Public Defender, Denver, Colorado, for
by CHIEF JUDGE LOEB. Kapelke[*] and Nieto[*], JJ.,
[¶1] Defendant, Kenneth Froehler, appeals
the judgment of conviction entered on a jury verdict finding
him guilty of sexual exploitation of a child. We affirm.
[¶2] Froehler checked into the Renaissance
Hotel in Denver in the early afternoon of March 17, 2009.
That evening, two men who appeared to be hotel guests found a
flash drive plugged into one of the hotel's business
center computers. The men opened some of the files on the
flash drive and discovered child pornography. They
immediately turned the flash drive over to hotel security.
The men did not identify themselves and asked not to be
involved further. The security guard contacted the police and
gave them the flash drive.
[¶3] The next morning, Froehler called the
front desk and asked if anyone had turned in a flash drive.
He described the missing flash drive as black with the words
" Datatraveler" on it. Because that description
matched the flash drive turned in the night before, the clerk
contacted the police.
[¶4] Responding officers approached Froehler
in the hotel parking lot and asked him about the flash drive.
Froehler described its appearance and told them it contained
personal pictures, pictures of Christmas lights, pictures of
his dog, and business invoices from his company. Later
investigation revealed that the flash drive contained those
items, as well as 155 images and 4 videos of child
pornography. Police later searched five laptops found in
Froehler's home but discovered no child pornography on
any of them.
[¶5] The prosecution charged Froehler with
one count of sexual exploitation of a child, a class four
felony. At trial, the defense argued that someone else put
child pornography on the flash drive after Froehler had
accidently left it in the hotel computer. A jury convicted
Froehler, and the trial court sentenced him to two years in
the custody of the Department of Corrections and three years
[¶6] On appeal, Froehler contends that the
trial court abused its discretion by allowing the detective
who investigated the case to give improper lay testimony
about (1) the dates associated with the images on the flash
drive and (2) ImageScan, the software program used to search
Froehler's laptops. Froehler contends that this evidence
constituted expert testimony that should have been excluded
because the detective was not disclosed or qualified as an
expert. For the reasons set forth below, we discern no
Standard of Review
[¶7] We review the trial court's
evidentiary rulings for an abuse of discretion. People v.
Stewart, 55 P.3d 107, 122 (Colo. 2002); People v.
Veren, 140 P.3d 131, 136 (Colo.App. 2005). A trial court
abuses its discretion if its ruling is manifestly arbitrary,
unreasonable, or unfair, or based on an erroneous view or
application of the law. Stewart, 55 P.3d at 122;
People v. Bondurant, 2012 COA 50, ¶ 79, 296
P.3d 200; People v. Esparza-Treto, 282 P.3d 471, 480
[¶8] Froehler timely objected to the
detective's testimony. Accordingly, we apply the harmless
error standard for reversal. See Stewart,
55 P.3d at 124; People v. Ramos, 2012 COA 191,
¶ 6 ( cert. granted Feb. 18, 2014). Under this
standard, we may not reverse a conviction if we " can
say with fair assurance that, in light of the entire record
of the trial, the error did not substantially influence the
verdict or impair the fairness of the trial."
Stewart, 55 P.3d at 124 (internal quotation marks
[¶9] We reject Froehler's contention
that the constitutional harmless error standard applies here.
Colorado appellate courts have uniformly applied the ordinary
harmless error standard where, as here, the defendant
contends that expert testimony was improperly admitted as lay
testimony and the objection was preserved. See, e.g.,
id.; Ramos, ¶ 6; Veren, 140 P.3d
[¶10] Whether the trial court abused its
discretion here turns on whether admission of the
detective's testimony was proper under CRE 701.
Stewart, 55 P.3d at 122. That rule, which governs
lay opinion testimony, applies because the prosecution did
not seek to qualify the detective as an expert witness under
CRE 702. Id.
[¶11] Under CRE 701, a witness who is not
testifying as an expert may give testimony in the form of
opinions or inferences only if those opinions or inferences
(a) rationally based on the perception of the witness, (b)
helpful to a clear understanding of the witness'
testimony or the determination of a fact in issue, and (c)
not based on scientific, technical, or other specialized
knowledge within the scope of Rule 702.
argument focuses on the third requirement, which prohibits
opinions based on " scientific, technical, or other
specialized knowledge" from being admitted as lay
[¶12] In determining whether testimony is
lay or expert, the critical inquiry is whether a witness'
testimony is based upon " specialized knowledge."
Veren, 140 P.3d at 137. Lay witness opinion
testimony is proper only if the opinions or inferences "
do not require any specialized knowledge and could be reached
by any ordinary person." Id. (internal
quotation marks omitted). In deciding whether an opinion is
one that could be reached by any ordinary person, courts
consider whether ordinary citizens can be expected to know
certain information or to have had certain experiences.
Id. Courts also consider " whether the opinion
results from 'a process of reasoning familiar in everyday
life,' or 'a process of reasoning which can be
mastered only by specialists in the field.'"
Id. (quoting People v. Rincon, 140 P.3d
976, 983 (Colo.App. 2005)).
[¶13] In People v. Stewart, the
supreme court recognized the difficulty in classifying a
police officer's testimony as expert or lay opinion
testimony. 55 P.3d at 123. Police officers regularly, and
appropriately, offer testimony under CRE 701 based on their
perceptions and experiences. Id. However, "
[o]fficer testimony becomes objectionable when what is
essentially expert testimony is improperly admitted under the
guise of lay opinions." Id. The court held that
where an officer's testimony is based not only on his or
her perceptions, observations, and experiences, but also on
the officer's specialized training or education, the
officer must be properly qualified as an expert before
offering such testimony. Id. at 124.
[¶14] The parties have not cited, and we
have not found, any published Colorado appellate case that
has addressed the distinction between lay and expert
testimony in the context of computer-related testimony.
Because CRE 701 mirrors Rule 701 of the Federal Rules of
Evidence, we look to federal cases construing that rule for
guidance. See Stewart, 55 P.3d at 123.
[¶15] In United States v. Ganier,
468 F.3d 920, 924 (6th Cir. 2006), the Sixth Circuit
considered testimony by a forensic computer specialist who
used forensic software to determine what searches were run on
a computer. The court rejected the Government's argument
that this was " simply lay testimony available by
running commercially-available software, obtaining results,
and reciting them." Id. at 925 (internal
quotation marks omitted). The court reasoned that
interpreting the reports generated by the software would
require the specialist to " apply knowledge and
familiarity with computers and the particular forensic
software well beyond that of the average layperson."
Id. at 926. It distinguished this type of knowledge
from the average lay person's familiarity with commonly
used software programs:
Software programs such as Microsoft Word and Outlook may be
as commonly used as home medical thermometers, but the
forensic tests [the specialist] ran are more akin to
specialized medical tests run by physicians. The average
layperson today may be able to interpret the outputs of
popular software programs as easily as he or she interprets
everyday vernacular, but the interpretation [the specialist]
needed to apply to make sense of the software reports is more
similar to the specialized knowledge police officers use to
interpret slang and code words used by drug dealers.
Id. (citations omitted). The court concluded that
the testimony at issue involved " scientific, technical,
or other specialized knowledge" and constituted expert
[¶16] In United States v. Wilson,
408 Fed.Appx. 798, 808 (5th Cir. 2010) (unpublished opinion),
the Fifth Circuit considered testimony by an investigator who
reviewed the defendant's e-mail account and, based on the
empty sent-box, determined that the defendant had deleted all
sent e-mails. Id. The investigator did not use
forensic software, and his computer experience was limited to
using Microsoft Office products. Id. The court
concluded that his examination of the e-mail account fell
" within the realm of knowledge of the average lay
person" and was " based on reasoning familiar in
everyday life." Id. (internal quotation marks
omitted). Accordingly, it was properly admitted as lay
opinion testimony. Id.
[¶17] Similarly, in United States v.
Lee, 339 Fed.Appx. 153, 160 (3d Cir. 2009) (unpublished
opinion), the Third Circuit held that a witness who used a
map prepared by a GPS computer program to calculate the
distance between two buildings properly testified as a lay
witness. The court reasoned that the witness " relie[d]
on a tool used in everyday life, and require[d] no
specialized training or knowledge." Id.
[¶18] Finally, in United States v.
Marsh, 568 Fed.Appx. 15, 16-17 (2d Cir. 2014)
(unpublished opinion), the Second Circuit concluded that an
FBI agent who used a forensic extraction device to retrieve
text messages from a cell phone properly gave lay testimony
about the contents of the messages. The court reasoned that
he " did not purport to render an opinion based on the
application of specialized knowledge to a particular set of
facts; nor did his testimony turn on or require a technical
understanding of the programming or internal mechanics of the
technology." Id. at 17.
[¶19] With these cases in mind, we now turn
to the detective's testimony in this case.
Testimony About Image Dates
[¶20] Froehler first contends that the trial
court abused its discretion in allowing the detective to
testify that the " date created" and " date
modified" associated with the pornographic images on the
flash drive preceded the date of Froehler's hotel stay.
Froehler argues that this constituted expert testimony that
was improperly admitted as lay testimony. We disagree.
Trial Court Proceedings
[¶21] During her investigation, the
detective sent the flash drive to the Rocky Mountain Computer
Forensic Lab. The lab used forensic software to extract
information about the images, including dates they were
created, modified, and accessed. The lab placed the contents
of the flash drive on a CD and provided a report listing the
dates associated with the images.
[¶22] The defense requested disclosure of
expert testimony before trial. The prosecution represented
that it would not introduce any expert testimony but would
have the detective testify as a lay witness about the dates
in the lab report. On the morning of trial, the defense moved
to exclude the report and related testimony, arguing, among
other grounds, that its admission through a lay witness would
[¶23] After hearing arguments from counsel,
the trial court ruled that the detective would not be
permitted to testify about information obtained from the
lab's forensic analysis. However, the court ruled that
the detective could give lay testimony about any information
she herself observed by looking on the flash drive.
[¶24] Following the court's ruling, the
detective plugged the flash drive into her computer and
examined the images herself without the assistance of the
lab's forensic software. She was then permitted to
testify at trial based on her own personal observations.
[¶25] On direct examination, the detective
testified that she personally observed the created, modified,
and accessed dates when she clicked on the images on the
flash drive. She explained that she right-clicked each image
file and hit " properties," and the computer then
showed the created, modified, and accessed dates associated
with the file. She was unable to view prior access dates
because when she clicked on the file, the accessed date
changed to the date she looked at it. However, she did
observe the created and modified dates. She testified that
those dates were prior to March 17, 2009, the date Froehler
checked into the hotel.
[¶26] We conclude that the detective's
testimony about the dates associated with the image files was
properly admitted as lay witness testimony. The detective
testified about the dates she personally viewed during her
examination of the flash drive, which was separate from the
lab's forensic analysis. She did not use forensic
software to extract the dates, nor did she rely on
information generated by the lab's forensic analysis.
Cf. Ganier, 468 F.3d at 926. Rather, she
accessed the dates simply by plugging the flash drive into
her computer and right-clicking on the image files. In our
view, the method she used to view the dates did not require
any specialized knowledge or familiarity with computers
beyond that of the average lay person. Right-clicking on a
file to view its properties requires some basic computer
competency, but it is within the realm of knowledge of
ordinary people who use computers in everyday life. See
also Wilson, 408 Fed.Appx. at 808 (viewing
e-mail sent-box was " within the realm of knowledge of
the average lay person" ); Lee, 339 Fed.Appx.
at 160 (using GPS map " require[d] no specialized
training or knowledge" ).
[¶27] Moreover, the detective did not
testify about the meaning or significance of the dates on the
flash drive. For example, she did not explain whether "
date created" referred to the date that the file was
originally created or the date the file was loaded onto the
flash drive. Nor did she testify to conclusions or inferences
based on the dates. She simply reported the dates she
observed, without interpreting them. Any ordinary person
could make the same observation simply by clicking on the
[¶28] Under these circumstances, we conclude
that the detective's testimony about the image dates was
not based on " scientific, technical, or other
specialized knowledge" within the scope of CRE 702.
Accordingly, it was properly admitted as lay testimony under
Testimony About ImageScan Software
[¶29] Froehler next contends that the trial
court abused its discretion in allowing the detective to give
lay testimony about the ImageScan software program used to
search Froehler's home computers, arguing that it also
constituted expert testimony. Although this is a closer
issue, we agree that the detective's testimony was
improperly admitted as lay testimony. Nevertheless, we
conclude that its admission was harmless under the
circumstances of this case.
Trial Court Proceedings
[¶30] The parties stipulated to certain
facts regarding the search of Froehler's home computers.
During cross-examination of the detective, the court read
this stipulation to the jury:
The parties have agreed upon the following facts which you
may accept as true:
1) Pursuant to a legal request from the Denver Police
Department, the McHenry County Illinois Sheriff's
Department seized computers from the home of Kenneth Froehler
. . . on November 11, 2009.
2) The Sheriff's [sic] did not call Mr. Froehler prior to
appearing at his home to conduct the search.
3) They collected two Toshiba Satellite notebook computers, a
Panasonic notebook computer, and two Sony notebook computers.
4) Utilizing a program called Image Scan, the McHenry County
Illinois Sheriff's Department scanned all files and media
in Mr. Froehler's computers.
5) Image Scan is a software tool which was created for law
enforcement by the FBI's Computer Analysis Response Team.
6) No images of child pornography were found on any of the
computers seized from Mr. Froehler's home.
[¶31] On redirect examination, the
prosecutor asked the detective what ImageScan was. Defense
counsel objected on the basis that the detective had not been
qualified as an expert. The court overruled the objection and
allowed the detective to testify as follows:
ImageScan was developed by the FBI for law enforcement to do
on-site search of a computer, . . . it just runs through the
computer and pulls out any pictures.
. . . It doesn't do like a full forensic search or
anything, literally just pulling the pictures. And once it
does that, then it puts it in a format where you can click
through thumbnails of pictures and see if any of them are
related to your case, but it doesn't go beyond just the
detective also confirmed that she had personally used
[¶32] The prosecutor next asked the
detective what types of things ImageScan would not find.
Defense counsel again objected, and the court again overruled
her objection. The detective then testified about the
limitations of ImageScan:
It's not going to give you a history of what's been
going on with the computer. It literally just pulls up the
images that are on the computer. If somebody's used a
wipe program on a computer, or if they have a file sharing
program and then they clear it out afterwards, ImageScan is
not going to give you the history of that. It's only
going to give you the images that are on there.
[I]f it had been deleted but not cleared out yet, then it
would pull up the deleted image, but it's not going to do
a search for anything really beyond that.
[I]f it's an image and you just deleted it, ImageScan
might still have it, but as time goes on, that area gets
written over, so if that's a file there or an image and
it's deleted and then it's written over, I believe
ImageScan is not going to find it.
[¶33] Finally, the prosecutor asked the
detective whether ImageScan would be able to find pictures
that had been saved on a flash drive. The detective
responded: " If somebody's using a computer and
moving it -- directly downloaded through the computer to an
external drive, it's not going to -- the images won't
be on the computer for ImageScan to pull up."
[¶34] Defense counsel briefly
recross-examined the detective and confirmed that no child
pornography had been found on Froehler's home computers.
Lay or Expert Testimony
[¶35] Whether the detective's testimony
about ImageScan was expert testimony or lay testimony is a
close question. On the one hand, the testimony was based, at
least in part, on the detective's personal experience
with using the program. See Stewart, 55
P.3d at 123 (noting that police officers regularly offer
testimony under CRE 701 based on their perceptions and
experiences). She did not claim to have expertise in forensic
computer analysis, nor did she describe any specialized
training related to ImageScan as a basis for her testimony.
See id. at 124 (officer's testimony
based on specialized training is expert testimony);
cf. Ganier, 468 F.3d at 926.
[¶36] On the other hand, her testimony
concerned a particular software program that was developed
specifically for law enforcement. The general public could
not be expected to have experience with, or even access to,
that software. See Veren, 140 P.3d at 137;
see also Ganier, 468 F.3d at 925-26
(interpretation of a report generated by forensic software
was expert testimony, even where such software was
commercially available); cf. Wilson, 408
Fed.Appx. at 808 (no expert testimony where investigator
whose only computer experience was using Microsoft Office
looked at e-mail account without forensic software).
Moreover, the detective's testimony went beyond
explaining the search that was conducted in this case. She
gave a technical description of the program's
capabilities and limitations, and she offered assessments
about whether it could retrieve images under various
hypothetical scenarios. In our view, this testimony required
specialized knowledge beyond that of the average layperson,
including at least some technical understanding of how the
program operated. Cf. Marsh, 568 Fed.Appx.
at 17 (no expert testimony where testimony did not "
turn on or require a technical understanding of the
programming or internal mechanics of the technology" );
People v. Stewart, No. 303879, 2012 WL 3966300, at
*1 (Mich. Ct.App. Sept. 11, 2012) (unpublished opinion) (FBI
forensic examiner did not give expert testimony where using
forensic software program did not require specialized
knowledge or training and forensic examiner did not testify
about how the software worked).
[¶37] On balance, we conclude that the
detective's testimony about ImageScan was based on "
specialized knowledge" within the scope of CRE 702 and,
therefore, constituted expert testimony. Accordingly, the
trial court erred in admitting it as lay testimony under CRE
[¶38] We next apply a harmless error
analysis to determine whether the error warrants reversal. We
conclude that the admission of the detective's expert
testimony was harmless in this case.
[¶39] The improperly admitted testimony
about ImageScan related to the search of Froehler's home
computers, not the flash drive which was the basis for the
charged offense. It was only tangentially relevant to the
central disputed issue in this case -- whether Froehler
" knowingly possessed" the child pornography on the
flash drive. See § 18-6-403(3)(b.5), C.R.S.
2014 (" knowingly" is an element of the offense of
sexual exploitation of a child).
[¶40] Froehler argues that the absence of
child pornography on his computers " tended to make it
less likely" that he put the child pornography on the
flash drive, because one could " infer that someone who
has child pornography on a flash drive probably has child
pornography on other electronic devices." Thus, he
claims that the detective's testimony about
ImageScan's limitations undermined the exculpatory value
of that evidence. Even according to this argument, the link
between the ImageScan testimony and the flash drive is
attenuated. Evidence about the software used to search
Froehler's home computers had no direct bearing on
whether Froehler " knowingly possessed" the child
pornography on the flash drive.
[¶41] Moreover, the detective's
testimony about ImageScan was not the only evidence of "
knowing possession." In his closing argument, the
prosecutor relied on other evidence admitted without
objection to show that the flash drive contained child
pornography before Froehler left it in the hotel's
business center. Specifically, the prosecutor highlighted:
o testimony that the business center was busy during
o photographs showing that the screen of the computer where
Froehler's flash drive was found faced the hallway; and
o testimony that the child pornography on the flash drive was
organized into folders.
prosecutor argued that it was unlikely someone could have
downloaded 155 images and 4 videos of child pornography on
the business center computer, put them on the flash drive,
and organized them into folders without being seen. He also
relied on the detective's testimony that the dates on the
image files preceded the date of Froehler's stay, which,
as we have concluded above, was properly admitted.
[¶42] Given the other evidence of "
knowing possession," as well as the attenuated link
between that disputed issue and the ImageScan testimony, we
conclude that the improperly admitted testimony did not
" substantially influence the verdict or impair the
fairness of the trial." Stewart, 55 P.3d at 124
(internal quotation marks omitted); cf.
Veren, 140 P.3d at 140 (officers' improperly
admitted expert testimony was not harmless because it was the
" key testimony at trial" establishing an element
of the crime).
[¶43] Froehler contends that the failure to
disclose the detective's expert testimony before trial
prevented defense counsel from adequately preparing for
cross-examination or hiring an expert to rebut the
detective's opinions. However, Froehler did not ask for a
continuance at trial. See People v. Greer,
262 P.3d 920, 931 (Colo.App. 2011) (" [D]efendant's
claim that he was unfairly surprised and unable to prepare
adequately for cross-examination is discredited by his
failure to move for a continuance." ). Nor does Froehler
explain how defense counsel's cross-examination would
have been different had the detective's testimony been
disclosed prior to trial. Likewise, he does not explain how,
if at all, a defense expert would have rebutted the
detective's testimony about ImageScan's limitations.
[¶44] Under these circumstances, we conclude
that any error in admitting the detective's testimony
about ImageScan was harmless and does not warrant reversal.
[¶45] The judgment is affirmed.
KAPELKE and JUDGE NIETO concur.
[*]Sitting by assignment of the Chief Justice
under provisions of Colo. Const. art. VI, § 5(3), and
§ 24-51-1105, C.R.S. 2014.
[*]Sitting by assignment of the Chief Justice
under provisions of Colo. Const. art. VI, § 5(3), and
§ 24-51-1105, C.R.S. 2014.