[DO NOT PUBLISH]
IN THE UNITED STATES COURT OF APPEALS
FOR THE ELEVENTH CIRCUIT
________________________ FILED
U.S. COURT OF APPEALS
No. 11-14743 ELEVENTH CIRCUIT
JUNE 26, 2012
Non-Argument Calendar
JOHN LEY
________________________
CLERK
D.C. Docket No. 2:11-cr-00076-AKK-HGD-1
UNITED STATES OF AMERICA,
Plaintiff-Appellee,
versus
ORLANDO BARNES,
Defendant-Appellant.
__________________________
Appeal from the United States District Court
for the Northern District of Alabama
_________________________
(June 26, 2012)
Before HULL, JORDAN and ANDERSON, Circuit Judges.
PER CURIAM:
After a jury trial, Orlando Barnes1 appeals his convictions for armed bank
robbery, in violation of 18 U.S.C. § 2113(a) and (d), carrying a firearm during and
in relation to a crime of violence, in violation of 18 U.S.C. § 924(c)(1)(A)(ii), and
possession of a firearm by a convicted felon, in violation of 18 U.S.C. § 922(g)(1).
After review, we affirm.
I. TRIAL EVIDENCE
Because Barnes raises evidentiary issues on appeal, we first review the
relevant trial evidence.
A. The Bank Robbery
On June 2, 2010, two men robbed a bank in Pleasant Grove, Alabama. The
first robber to enter the bank, wielded a gun, and wore a white shirt, a white cap
and a thick, strange-looking beard. The first robber jumped over the counter top
and took money from the teller stations. Then, a second robber entered the bank
and said, “We have a bailer, We have a bailer.” At that point, the robbers left and
drove away in a silver vehicle.
B. Officer Cutcher’s Chase
1
We refer to the Defendant as Orlando Barnes, his name as it appears in the indictment,
the judgment of conviction and other court documents. We note, however, that the Defendant’s
name is actually Orlanda Barnes, and that the trial court and witnesses referred to him
interchangeably as “Orlando” and “Orlanda.”
2
Officer Matthew Cutcher testified that police dispatch notified him that the
bank robbery suspects, two black males in a silver car, were in the vicinity of a
subdivision. As Officer Cutcher proceeded into the subdivision, he saw two
suspects drive toward him at a high speed. Officer Cutcher turned his car to block
the suspect vehicle, which drove on the grass and got away.
As the suspect vehicle passed Officer Cutcher’s patrol car, Officer Cutcher
saw two people inside, a driver and a passenger. Based on the subsequent chase
and arrest recounted below, Officer Cutcher identified Defendant Barnes the as
passenger. The chase and arrest occurred in this fashion.
As Officer Cutcher pursued the suspect vehicle, he learned that a witness
reported that the bank robbers had worn fake beards. He also saw the occupants of
the suspect vehicle throw two black, fluffy objects from the windows. When the
suspect vehicle failed to stop at a stop sign, it collided with another vehicle, ran
through a chain link fence and hit a house. Officer Cutcher exited his patrol car,
and he saw the suspects run from the vehicle.
Officer Cutcher chased the passenger and another officer pursued the driver
(who threw a white cap to the ground as he ran away). Officer Cutcher was about
forty-five feet away from the passenger and could see that he was tall, with a
medium build and very short hair. The passenger wore tan hiking boots,
3
extremely dark jeans and a white, long-sleeved, collared dress shirt. When the
passenger rounded the corner of the house, Officer Cutcher lost sight of him for
about two seconds. When Officer Cutcher caught sight of the passenger again, he
was about forty feet away.
Officer Cutcher followed the passenger across the back yard and over a
fence and toward a railroad bed. When the passenger climbed over the steep
railroad embankment, Officer Cutcher lost sight of the passenger again, this time
for about nine seconds.
As Officer Cutcher ran in the direction the passenger had disappeared, he
found a white, long-sleeved shirt lying in the grass near an abandoned house.
Officer Cutcher looked up and saw Defendant Barnes sixty feet away. Barnes was
standing on a landing to some stairs. The stairs led to a garage apartment behind
the abandoned house. Defendant Barnes was wearing the same boots and jeans,
was the same height and had the same hair cut as the passenger Officer Cutcher
had just been pursuing, except that Defendant Barnes was wearing a plain white t-
shirt.
As Officer Cutcher approached, Defendant Barnes looked surprised and
appeared winded. Barnes had his palms open toward Officer Cutcher, and Officer
Cutcher noticed “black, sticky glue stuff” that was “flaky and balled on the end of
4
[the Defendant’s] fingertips.” Officer Cutcher asked Barnes who he was, and
Barnes replied, “What’s going on?” Officer Cutcher responded, “A bank
robbery.” Barnes turned toward the garage and said, “I live here.” Officer
Cutcher stepped within five or six feet of Barnes and noticed that Barnes had
“little black flecks and balls all in his beard stubble.”
Officer Cutcher stepped back and told Barnes to put his hands on a nearby
vehicle. Barnes began to run away. Officer Cutcher followed and yelled for him
to stop. After about one hundred feet, Barnes stopped and put his hands up.
Officer Cutcher pulled Barnes to the ground and, with the help of another officer
who was nearby, placed Barnes in handcuffs. As he did this, Officer Cutcher saw
that both sides of Barnes’s face, from his ear to his goatee, were covered in a
flaky, sticky substance “like latex paint.” Officer Cutcher went into the garage
apartment to look for the other suspect and found that it smelled of mildew and
had no electricity, water or furniture.
After arresting Barnes, Officer Cutcher took photographs and collected
evidence from the chase, including, among other things: (1) hairs from the white
hat the driver threw on the ground outside the suspect vehicle; (2) two guns and
stacks of currency from a pillow case found inside the suspect vehicle; (3) pieces
of the black latex-like substance and hairs and fibers found on the white, long-
5
sleeved shirt; (4) the black latex-like substance containing hairs found in the
passenger seat of the suspect vehicle; and (5) the black latex-like substance
containing hair found in the back seat of the patrol car that transported Barnes to
jail. Officer Cutcher also recovered one of the fake beards by the side of the road.
C. Motions in Limine
Defendant Barnes filed three pre-trial motions in limine seeking to prevent
the government from offering expert opinion testimony regarding boot prints, hair
and adhesives. Barnes argued that the government’s experts could not testify to a
reasonable degree of scientific certainty and thus their testimony did not meet the
requirements of Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 113
S. Ct. 2786 (1993).
At trial, the district court denied all three motions in limine, finding that the
expert testimony in question satisfied the Daubert standard because the experts
would testify to valid scientific or technical knowledge and the testimony would
assist the trier of fact with an issue in the case. The district court also noted that
Barnes could raise his key points through cross-examination and contradictory
evidence. The district court granted Barnes a continuing objection to the expert
testimony.
D. Boot Print Expert
6
Brian McVicker, an FBI laboratory examiner, analyzes footwear impression
evidence. McVicker testified that to conduct footwear impression analysis, he
visually compares known footwear to either a digital image, a “tape lift,” or a cast
of the footwear impression found at the crime scene. McVicker explained that he
first looks for similarities in the pattern on the bottom of the footwear or “outsole.”
If there are similarities, McVicker compares the physical size characteristics. To
do this, McVicker makes a test impression from the known shoe, or “test
impression,” by applying fingerprint powder to the bottom of the known shoe and
walking across an adhesive sheet, creating a black footwear impression on a
transparent background. McVicker then superimposes the test print over the tape
lift impression from the crime scene to compare the size, shape and design of the
two prints. McVicker testified that this type of footwear impression analysis is
“generally accepted throughout the world.”
McVicker conducted this footwear impression analysis between (1) “tape
lift” impressions found on the counter top at the bank and (2) “test impressions” of
the boots Defendant Barnes was wearing when arrested. The government first
sought to introduce the test impressions McVicker created using Barnes’s boots.
Barnes objected, arguing that “everybody’s gait’s different and . . . weight, size, all
that stuff is different.” The district court initially sustained the objection.
7
McVicker then testified about the tape lift impressions from the bank.
Based on his analysis of the tape lifts, McVicker found that the crime scene
impressions had: (1) angular elements around the perimeter and circular elements
in the center that corresponded to the bottom of Barnes’s left boot; (2) a pattern of
circular elements in the center and chevron elements around the perimeter and a
V-shaped element at the top that was similar to the toe of Barnes’s boots; (3) a
distinctive crescent-shaped wear characteristic that corresponded in size, design
and orientation to the upper left portion of Barnes’s left boot. McVicker also
found that the physical size characteristics of one crime scene impression
corresponded to Barnes’s boot, from the heel to the toe, including the spatial
arrangement of the pattern on the sole.
McVicker could not say “definitively, 100 percent” that Barnes’s boots
made the impressions in the tape lifts. McVicker explained that “[d]ue to the
movement when the impressions were made, portions of the outsole did not
impress” and he “couldn’t see the characteristics that [he] needed to make an
identification.” Thus, McVicker opined, that one of the tape lifts “corresponded to
. . . the left boot . . . in outsole design, physical size,” and that the crescent-shaped
wear characteristic corresponded “and therefore could have made this particular
impression,” but that the other tape lifts only “shared similar design features with
8
the left or the right boot.”
Outside the jury’s presence, the district court revisited the admission of
McVicker’s test impressions made by walking in Barnes’s boots. Barnes renewed
his objection, arguing that the conditions (weight, gait and movement) under
which the test impressions and the crime scene impressions were made did not
necessarily match. McVicker clarified that a colleague, who wore a size 13 shoe,
made the impressions under his supervision. The district court now admitted the
test impressions, finding that Barnes could cross-examine McVicker as to the
conditions.
McVicker then testified about how he created the test impressions,
explaining that he powdered Barnes’s boots with fingerprint powder and had a co-
worker who wore a size 13 shoe put the boots on and walk across a sheet of clear
adhesive paper to make an impression. McVicker then made a transparency of the
impressions so he could compare physical size characteristics by superimposing
the transparency over the crime scene impressions. McVicker stated that the
comparison method using a transparency was the standard procedure for analyzing
footwear impressions and that he had used that procedure in every footwear
investigation he had conducted. McVicker concluded, based on such a
comparison, that the physical size characteristics of the crime scene and test
9
impressions corresponded and that Barnes’s boots “could have made” the crime
scene impressions. Although the tape lifts “shared similar design features,” with
the boots, the quality of the tape lift impressions was insufficient to make a more
conclusive opinion.
On cross-examination, McVicker testified, inter alia, that the boots collected
from Barnes were made by Timberland, a popular brand. McVicker agreed that
everyone has a different gait and that the co-worker who wore the boot during the
test did not jump on a counter. McVicker explained that he used the words
“correspond” and “similar,” in their ordinary sense, not as scientific terms.
McVicker said that “correspond” means that “two things are similar,” not that they
are exact or identical. McVicker agreed that his opinion was only that the boots
“could have . . . made” the crime scene impressions, not that they did make them
and reiterated that it was not possible to determine definitively that Barnes’s
Timberland boots created the impressions found at the crime scene. On redirect
examination, McVicker agreed that he was also unable to eliminate the
Timberland boots with respect to any of the crime scene impressions.
E. Hair and Fiber Expert
Sandra Koch, an FBI trace evidence examiner, performed the hair and fiber
analysis in Barnes’s case. Koch testified that she conducts hair and fiber
10
examinations in special processing rooms where she separates the hair and fiber
from other evidence. She then mounts the material onto slides for examination
under a comparison microscope, which permits comparison of two samples side by
side at a very high magnification.
Using this microscope, Koch can identify whether the evidence is fiber or
hair and whether it is human or animal hair. For human hair, which has three
layers, Koch can examine its microscopic characteristics and determine whether
the source person has European, African, Asian or Native American ancestry, what
part of the body the hair came from, whether the hair was artificially treated and
whether there are any roots.
Koch advised, however, that hair is “not a means of positive identification
to one individual to the exclusion of all others because” the range of
characteristics from different people can overlap. Thus, using microscopic
comparison, Koch can: (1) conclude that the characteristics are “consistent” such
that a “person can be included as a possible source”; (2) reach a “nil conclusion”
because there are both similarities and differences; or (3) conclude that “a hair is
microscopically dissimilar and not consistent with having come from a known
sample.”
In Barnes’s case, Koch examined sample hairs from a “fake beard” and
11
found that the beard was made of real human head hair with Negroid
characteristics, but without roots. Koch also examined hair found in debris from
the back seat of a patrol car that transported Barnes. Using a comparison
microscope, Koch compared the layers (the cuticle, cortex and medulla), the
pigment distribution and the patterning within the two hair samples. Koch
observed that the hairs from the back seat of the patrol car were Negroid head
hairs that exhibited the same microscopic characteristics as the hairs from the fake
beard. Thus, Koch concluded that the “two samples were consistent with having
come from the same person or that the person whose head hair made up that fake
beard could have been the source of the hairs found in the debris collected from
the patrol car.”
On cross-examination, Koch reiterated that hairs were not a means of
positive identification. Koch admitted that it was also a possibility that the two
samples came from different sources. When asked if she could quantify how many
people the patrol car sample could have come from, Koch stated that she could
not, as follows:
You really can’t get quantifiable numbers with hair examinations.
It really is an examination where you need a known sample. So I will
leave open the possibility that it could have come from somebody else
because the range of characteristics of different individuals can overlap.
However, I’d have to see another known sample to make a more
definitive statement.
12
When defense counsel pressed Koch to say whether the patrol car sample could
have come from ten other people or ten thousand other people, Koch said, “I
would probably not say ten thousand,” but when asked if it could have come from
five thousand people, Koch responded, “I cannot give you a number.” Koch
explained that she could not say how many other people in the world have hair
with the same microscopic characteristics because “there is no actual reliable way
to database hair analysis.”
On redirect, Koch acknowledged that hair analysis allowed her to draw only
one of three conclusions: (1) the hair was “consistent with a known sample or that
it exhibits the same microscopic characteristics” such that “the person or object
that those hairs came from could be included as a possible source of those hairs”;
(2) the “hair exhibits similarities and differences, and I cannot make a conclusion
because of those differences”; or (3) the hair is “microscopically dissimilar and is
not consistent or that person or that object could not have been a possible source
of those hairs.” In Barnes’s case, Koch’s conclusion was that “the hairs that came
from the debris from the back seat of the patrol car and the fake beard item . . .
exhibit the same microscopic characteristics” and that the fake beard “could be
included as a possible source of the items from the patrol car.”
F. Adhesive Expert
13
Maureen Bradley, an FBI chemist, analyzes paints, polymers and adhesive
materials. Bradley analyzed the black latex-like substance found (1) in the right,
front seat of the suspect vehicle, (2) in the pocket of the white, long-sleeved shirt
and (3) in the back seat of the patrol car that transported Barnes. Bradley
compared these substances to the black rubber material found on the fake beard
and found that they all had the same physical appearance, that is, they all were
black and elastomeric (or rubbery). Based on her visual examination, Bradley
concluded that the black latex-like substances found in the suspect vehicle, the
shirt pocket and the patrol car were “physically consistent to . . . the black material
on the fake beard.”
Bradley also analyzed the chemical composition of the samples using two
different instrumental methods and found that “they were comparable to one
another in chemical composition.” However, Bradley could not say definitively
that all the samples came from the same source because the material was
polyisoprene, or rubber cement, which was a common adhesive formulation, and
there were “not techniques that would necessarily differentiate different sources of
polyisoprene.”
On cross-examination, Bradley admitted that polyisoprene was a common
adhesive formulation that could be used for a number of different purposes.
14
Bradley could not say how many different people used the adhesive in Alabama in
the last two or three years.
G. Convictions and Sentence
At the close of the evidence, Barnes moved for a judgment of acquittal,
arguing, inter alia, that the government failed to prove that Barnes was the man
who robbed the bank. The district court denied the motion, finding that the
evidence was sufficient to support a guilty verdict.
The jury found Barnes guilty on all three counts. The district court
sentenced Barnes to a total sentence of 159 months’ imprisonment. Barnes filed
this appeal.
II. DISCUSSION
A. Officer Cutcher’s Lay Opinion Testimony
Defendant Barnes argues that the district court improperly admitted Officer
Cutcher’s testimony that Barnes was the passenger in the suspect vehicle. Barnes
contends that this testimony was not based on Officer Cutcher’s personal
knowledge as required by Federal Rules of Evidence 602 and 701.2
Under Rule 602, “[a] witness may testify to a matter only if evidence is
2
We review a district court’s decision to admit evidence for abuse of discretion. United
States v. Smith, 459 F.3d 1276, 1295 (11th Cir. 2006).
15
introduced sufficient to support a finding that the witness has personal knowledge
of the matter. Evidence to prove personal knowledge may consist of the witness’s
own testimony.” Fed. R. Evid. 602. A witness’s lay opinion is admissible if, inter
alia, it is “rationally based on the witness’s perception.” Fed. R. Evid. 701. This
limitation on lay opinion testimony is “‘the familiar requirement of first-hand
knowledge or observation.’” United States v. Jayyousi, 657 F.3d 1085, 1102 (11th
Cir. 2011) (quoting the advisory committee’s note to Rule 701).
The record belies Barnes’s claim that Officer Cutcher’s identification of
Barnes was not based on personal knowledge. Specifically, Officer Cutcher
testified that, during the vehicle chase, he learned that the bank robbers had worn
fake beards. He also saw the suspects throw black, fluffy objects from their
vehicle. After the crash, Officer Cutcher saw the passenger run from the suspect
vehicle, and he pursued the passenger on foot, staying within about forty feet of
him. Indeed, Officer Cutcher was able to observe the passenger’s physical
features and clothing and described them in detail.
Although Officer Cutcher very briefly lost sight of the passenger as he
climbed a steep embankment, Officer Cutcher saw nine seconds later (1) a white,
long-sleeved shirt (like the one worn by the passenger) lying on the ground, and
(2) standing sixty feet away, Defendant Barnes, who looked like the passenger in
16
every respect except that he was not wearing the white, long-sleeved dress shirt.
Defendant Barnes seemed surprised and winded. Defendant Barnes also had a
black, sticky substance on his face and hands, which was consistent with having
recently removed a fake beard.
Contrary to Barnes’s argument, nothing in the record suggests that Officer
Cutcher’s opinion was based on subsequent investigation. Rather, it is clear from
Officer Cutcher’s testimony that he believed Barnes was the passenger of the
suspect vehicle at the time he arrested Barnes and that Officer Cutcher’s belief was
based on his own observations during the chase.
In short, Officer Cutcher testified from personal knowledge about his
pursuit of the passenger in the suspect vehicle, as required by Rule 602. And,
Officer Cutcher’s opinion that Defendant Barnes was that passenger was rationally
based on his perceptions during the chase, as required by Rule 701. Therefore, the
district court did not abuse its discretion in admitting Officer Cutcher’s testimony
that Defendant Barnes was the passenger in the suspect vehicle whom he chased.
B. Forensic Expert Testimony
Defendant Barnes argues that the testimony of the three forensic
experts—McVicker (the boot print expert), Koch (the hair and fiber expert) and
Bradley (the adhesive expert)—should have been excluded as unreliable under
17
Daubert.3
Rule 702 of the Federal Rules of Evidence provides that:
A witness who is qualified as an expert by knowledge, skill, experience,
training, or education may testify in the form of an opinion or otherwise
if:
(a) the expert's scientific, technical, or other specialized
knowledge will help the trier of fact to understand the evidence or to
determine a fact in issue;
(b) the testimony is based on sufficient facts or data;
(c) the testimony is the product of reliable principles and methods;
and
(d) the expert has reliably applied the principles and methods to
the facts of the case.
Fed. R. Evid. 702. Barnes does not challenge the qualification of the three
forensic experts or argue that their testimony did not assist the trier of fact. Barnes
argues only that their opinions were unreliable. See United States v. Frazier, 387
F.3d 1244, 1260 (11th Cir. 2004) (en banc) (explaining that the proponent of
expert testimony has the burden to show qualification, reliability and helpfulness
to the jury).
In Daubert, the Supreme Court provided a non-exclusive list of factors for
district courts to consider in determining whether expert testimony is sufficiently
reliable. Daubert, 509 U.S. at 593-94, 113 S. Ct. at 2796-97. These factors
3
We review for abuse of discretion a district court’s decision regarding the admissibility
of expert testimony and the reliability of an expert opinion. United States v. Frazier, 387 F.3d
1244, 1258 (11th Cir. 2004) (en banc).
18
include: “(1) whether the expert’s theory can be and has been tested; (2) whether
the theory has been subjected to peer review and publication; (3) the known or
potential rate of error of the particular scientific technique; and (4) whether the
technique is generally accepted in the scientific community.” Frazier, 387 F.3d at
1262; see also United States v. Brown, 415 F.3d 1257, 1267 (11th Cir. 2005).
These factors also apply to assess the reliability of the expert’s opinion based on
experience or training rather than a rigorous scientific methodology. Frazier, 387
F.3d at 1262. The inquiry “is a flexible one” and “whether Daubert’s specific
factors are, or are not, reasonable measures of reliability in a particular case is a
matter that the law grants the trial judge broad latitude to determine.” Brown, 415
F.3d at 1267-68 (quotation marks omitted). Thus, not all factors “will apply in
every case, and in some cases other factors will be equally important in evaluating
the reliability of the proffered expert opinion.” Frazier, 387 F.3d at 1262.
First, Defendant Barnes asserts that McVicker’s testimony about the boot
print evidence was not based on reliable principles and methods. Specifically,
Defendant Barnes contends that “conditions must be identical to produce reliable
results,” and, thus, a test print created by a person of “unknown height, weight,
and gait” cannot be reliably compared to an impression made by another person
with a different height, weight, and gait.
19
Barnes offers no authority or evidence to support his proposition that
footwear impression analysis is reliable only if a person of the same height, weight
and gait is used to make the comparison print. Moreover, McVicker testified that
the methods he used were the standard procedures for footprint analysis generally
accepted throughout the world.
Barnes also argues that all three expert opinions should have been excluded
as unreliable because they “r[an] afoul of the scientific requirement of at least
some degree of quantification.” Barnes relies on United States v. Frazier, 387
F.3d 1244 (11th Cir. 2004) (en banc), but Frazier imposes no such requirement.
Frazier does not require all experts to provide a quantitative basis for their
opinions, as Barnes suggests.4 Rather, Frazier requires experts who provide
probabilistic opinions to also provide quantitative bases for them, such as
scientific studies or quantified personal experiences. See id. at 1265.5
4
In Frazier, the district court excluded a forensic investigator’s opinion that some transfer
of hair, fibers or fluids from the perpetrator of a sexual assault to the victim “would be
expected.” Id. at 1252. This Court affirmed because: (1) the meaning of “expected” was
imprecise and could mean a virtual certainty, a strong probability, a possibility that was more
likely than not or just a possibility; and (2) the expert offered no reliable foundation, in the form
of either studies or experience, to support “his ‘expectancy’ opinion.” Id. at 1265-66. This Court
explained that the reliability of the expert’s opinion “that expresses an intrinsically probabilistic
or quantitative idea” cannot be assessed when the expert does not provide the basis for that
probabilistic or quantitative idea. Id. at 1265.
5
The two other decisions Barnes cites are also inapposite and, in any event, are not
binding precedent. See Kunz v. DeFelice, 538 F.3d 667, 675-76 (7th Cir. 2008) (concluding
district court properly excluded police officer’s expert witness who would have testified to
20
Here, the challenged experts did not express probabilistic or quantitative
opinions. That is, none of the experts expressed a degree of likelihood or
probability; rather, they said that something was a possibility and explicitly
declined to opine as to probability. For example, McVicker testified that the test
impressions he made with Barnes’s boots “corresponded” (i.e., was “similar” ) to
the crime scene impressions and that Barnes’s boots “could have” made the prints
left on the bank’s counter top. However, McVicker did not testify to how likely it
was that Barnes’s boots, as opposed to any other person’s boots, made the
impressions. In fact, McVicker explained that the crime scene impressions were
too distorted by movement to draw a more conclusive opinion.
Similarly, Koch testified that the hairs found in the back seat of the patrol
car were “consistent” with hairs from the fake beard. Although Koch opined that
it was possible the two hair samples came from the same source, she did not
quantify how likely it was. Indeed, Koch explained that hair analysis, which
compared hair evidence to known samples, could not provide this sort of
quantitative information.
arrestee’s ability to recall events after using heroin because, among other things, the expert
“knew neither a baseline against which to judge whether [the arrestee] was impaired, nor [the
arrestee’s] habituation level”); United States v. Carroll, 450 F. App’x 937, 940 (11th Cir. 2012)
(concluding that district court was within discretion to exclude polygraph evidence “when no
expert witness was present to explain the meaning of and context of the results”).
21
For this reason, we agree with the government that the expert opinions in
this case are more akin to the expert opinion in United States v. Brown, 415 F.3d
1257 (11th Cir. 2005). In Brown, the district court admitted, over the defendant’s
Daubert objection, two chemists’ opinions that the chemical structures of 1.4-
butanediol, an industrial solvent, and GHB, a “date rape” drug, were “substantially
similar.” Brown, 415 F.3d at 1260. At trial, the chemists conceded that their
“method and conclusions were not quantifiable or testable by the scientific
method” but instead “were based on visual comparisons of the molecular models
combined with expert knowledge of chemistry.” Id. at 1267. The government did
not submit any studies or papers indicating that this visual comparison
methodology or the chemists’ opinions had been subjected to peer review. Id.
But, the chemists did testify that visual compariscon was the generally accepted
methodology. Id. This Court affirmed, stressing the flexibile nature of the
Daubert inquiry and the deferential abuse-of-discretion standard applied to a
district court’s reliability determination. Id. at 1267-68.
As in Brown, the forensic experts here used methodologies that did not
allow for quantification, but that were generally accepted. Moreover, Defendant
Barnes has not presented any evidence to the contrary. Under the circumstances
of this case, we cannot say it was an abuse of discretion to admit the expert
22
opinions.
For all these reasons, we affirm Barnes’s convictions.
AFFIRMED.
23