The People of the State of Colorado, v. William Anthony Tunis
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COLORADO COURT OF APPEALS
2013 COA 161
_______________________________________________________________________________
Court of Appeals No. 09CA0593
Jefferson County District Court No. 07CR697
Honorable Margie L. Enquist, Judge
_______________________________________________________________________________
The People of the State of Colorado,
Plaintiff-Appellee,
v.
William Anthony Tunis,
Defendant-Appellant.
_______________________________________________________________________________
JUDGMENT AFFIRMED, SENTENCE AFFIRMED IN PART AND VACATED IN
PART, AND CASE REMANDED WITH DIRECTIONS
Division V
Opinion by JUDGE WEBB
Loeb, C.J., and Plank*, J., concur
Prior Opinion Announced August 2, 2012, WITHDRAWN
Announced December 5, 2013
_______________________________________________________________________________
John W. Suthers, Attorney General, Deborah Isenberg Pratt, Assistant Attorney
General, Denver, Colorado, for Plaintiff-Appellee
Leslie A. Goldstein, Attorney at Law, L.L.C., Leslie A. Goldstein, Steamboat
Springs, Colorado, for Defendant-Appellant
*Sitting by assignment of the Chief Justice under provisions of Colo. Const. art.
VI, § 5(3), and § 24-51-1105, C.R.S. 2013.
¶1
The victim in this criminal case was sexually assaulted in her
home. Defendant, William Anthony Tunis, was charged with the
offense and, at a subsequent jury trial, he was identified as the
assailant based on the victim’s testimony and DNA evidence,
including Y Chromosome-Short Tandem Repeat (Y-STR) evidence.
Defendant was ultimately convicted of sexual assault and second
degree burglary, both class three felonies, and sentenced to the
Department of Corrections for an indeterminate term of twelve years
to life. His sentence included a determination that he qualified as a
sexually violent predator.
¶2
Defendant appeals from the judgment of conviction and
sentence, challenging, as an issue of first impression, the reliability
of the Y-STR evidence. We affirm the judgment, but conclude that
the sexually violent predator portion of defendant’s sentence must
be vacated.
I. Y-STR Evidence
¶3
For three reasons, defendant contends that the Y-STR
evidence, which was admitted through expert testimony, was
unreliable and the trial court therefore erred by admitting it. “We
review a trial court’s admission of expert testimony for an abuse of
1
discretion and will reverse only when that decision is manifestly
erroneous.” People v. Rector, 248 P.3d 1196, 1200 (Colo. 2011)
(citing People v. Ramirez, 155 P.3d 371, 380 (Colo. 2007)). We
disagree with defendant and conclude that the trial court did not
abuse its discretion.
A. Y-STR Analysis Generally
¶4
The following was not disputed at trial:
¶5
Every person has a unique genetic code. This code consists of
a unique pattern of DNA on the twenty-three pairs of chromosomes
that all humans have. Twenty-two of these pairs, called autosomes,
are not sex-determinative. A mother and father contribute equally,
and randomly, to the composition of their offspring’s autosomes.
¶6
However, the last pair of chromosomes determines the
offspring’s sex, and are called sex chromosomes. In females this
pair consists of two X chromosomes, while in males this pair
consists of one X and one Y chromosome. Because females carry
no Y chromosome, a male’s entire Y chromosome comes from his
father. Therefore, excluding consideration of very small changes
due to random mutation, a male’s Y chromosome contains the same
DNA and genetic code as all members of his male lineage.
2
¶7
Traditional forensic DNA analysis identifies individuals by
looking for specific types of DNA at specific locations across the
twenty-two pairs of autosomes. Analysts can compare a suspect’s
DNA type at a specific location on a chromosome to the DNA type at
the same location on the same chromosome from a crime scene
sample. If the types match, the DNA in the sample may have come
from the suspect.
¶8
Analysts can obtain a more accurate match by executing this
comparison for many different DNA types at different locations on
different chromosomes. Because autosomes contain a random
combination of DNA from an individual’s mother and father, and
discrete DNA types at different locations are inherited
independently of one another, the accuracy of the identification
increases exponentially when analysts find a DNA type match at
more than one location. This statistical analysis is called the
product rule because the probability of a match at one location is
multiplied by the probability of a match at another location, and so
on, resulting in an astronomically small probability that a random
person’s overall DNA profile would match the profile observed in the
sample and the suspect.
3
¶9
The physical process and methodology of Y-STR analysis is the
same as that of traditional forensic DNA analysis. In both cases,
the same techniques allow analysts, using one of several kits
manufactured by private companies, to compare DNA types at
specific locations. However, Y-STR analysis only examines DNA
types on the Y chromosome. Because the Y chromosome passes
from father to son largely unchanged, the DNA types at different
locations on the Y chromosomes are not inherited independently of
one another. Therefore, the product rule is inapplicable.
¶ 10
Instead of the product rule, analysts use what is known as the
counting method in Y-STR analysis. Analysts assemble a Y
chromosome profile from DNA found in a crime scene sample by
identifying different DNA types at specific locations on the Y
chromosome. If the profile from the sample matches the suspect’s
Y chromosome profile, he and his paternal relatives cannot be ruled
out as the source of the sample. Analysts then search for the same
DNA profile in a database of several thousand individuals’ profiles.
Based on the number of individuals in the database who share that
profile, analysts can then calculate what portion of the general
population shares that profile. In other words, if the matching
4
profile occurs at a rate of 5% in the database, about 95% of the
population represented by that database can be excluded as the
source of the sample.
B. Governing Law
¶ 11
The admissibility of scientific evidence in Colorado is governed
by CRE 702 and 403. People v. Shreck, 22 P.3d 68, 78 (Colo. 2001).
¶ 12
CRE 702 requires the scientific evidence be both reliable and
relevant. See id. at 77. “In determining whether the [scientific]
evidence is reliable, a trial court should consider (1) whether the
scientific principles as to which the witness is testifying are
reasonably reliable, and (2) whether the witness is qualified to opine
on such matters.” Id. (citing Brooks v. People, 975 P.2d 1105, 1114
(Colo. 1999)). This reliability inquiry “should be broad in nature
and consider the totality of the circumstances of each specific case,”
and need not turn on any particular factor or factors. Id. Also, a
trial court must issue specific findings as it applies the CRE 702
analysis. Id. at 79.
¶ 13
Because defendant challenges only the reliability of the
scientific principles underlying the Y-STR evidence, we need not
address the additional criteria set forth in Shreck and CRE 403.
5
C. Procedural History
¶ 14
The court conducted a pretrial Shreck hearing to determine
the admissibility of the Y-STR evidence offered by the prosecutor.
The court qualified as an expert witness the analyst from the
Colorado Bureau of Investigation (CBI) who conducted the Y-STR
analysis. She testified about the methodology and reliability of YSTR analysis generally, and in this case. At the conclusion of the
hearing, the court ruled that the Y-STR evidence was admissible
under CRE 702 and 403 because: (1) the basic science,
methodology, and procedures were substantially similar to the
traditional DNA analysis held to be reliable in Shreck; (2) there was
no risk of affirmative misidentification because the Y-STR evidence
was used only to show that defendant and his paternal male
ancestors could not be excluded as the assailant; (3) the Y-STR
evidence was relevant to the identification of the assailant; and (4)
the probative value of the Y-STR evidence was not outweighed by
the danger of unfair prejudice.
¶ 15
Later, at trial, the analyst testified to the following:
¶ 16
A DNA sample obtained from the victim’s inner thigh shortly
after the assault contained male and female DNA. To better analyze
6
only the male DNA, the analyst conducted a Y-STR analysis on this
sample. She sought to identify the DNA type at seventeen locations
on the Y chromosome and obtained interpretable results at seven of
those locations, resulting in a partial profile. At one of the seven
locations on the Y chromosome, she observed the presence of DNA
from more than one male. She then identified the major male
contributor and isolated it for further analysis. The major
contributor partial profile matched defendant’s profile. After
comparing these results to the YFiler Y-STR database and
conducting a statistical analysis using the counting method, the
analyst testified that she could not exclude defendant and members
of his male lineage as sources of the DNA in the inner thigh sample,
but she could exclude 99.6% of African Americans, 99% of
Caucasians, and 99.5% of Hispanics.
¶ 17
The Y-STR evidence from the victim’s inner thigh is the only Y-
STR evidence that suggested defendant was the assailant, and is
the only Y-STR evidence at issue on appeal.
D. Reliability of Y-STR Analysis
¶ 18
We disagree with defendant’s arguments that the scientific
principles underlying the Y-STR evidence were unreliable.
7
¶ 19
The Y-STR evidence was admitted through the testimony of the
analyst. Her background included extensive training and
experience with the types of partial mixture analyses at issue here,
she had been qualified as an expert in forensic DNA analysis in
several other cases, she had been conducting Y-STR analysis for
approximately one year, and she previously had given expert
testimony about Y-STR analysis. See Golob v. People, 180 P.3d
1006, 1012 (Colo. 2008) (expert qualification standard under CRE
702 is “liberal” and “expert may be qualified by any one of the five
factors specified in the rule: knowledge, skill, experience, training,
or education” (citing Huntoon v. TCI Cablevision of Colo., Inc., 969
P.2d 681, 690 (Colo. 1998))); People v. Lehmkuhl, 117 P.3d 98, 10304 (Colo. App. 2004) (that witness previously qualified and testified
as DNA expert was a fact supporting trial court’s ruling that witness
was qualified to opine about DNA evidence); see also Shreck, 22
P.3d at 77 (scientific evidence is reliable if the scientific principles
underlying the evidence are reliable and the expert testifying to the
evidence is qualified to opine on the evidence).
1. Scientific Standard
¶ 20
Defendant challenges the Y-STR analysis as unreliable
8
because, according to defendant, the analyst used her discretion
instead of a scientific standard to determine major and minor
contributors to the inner thigh DNA sample that contained a
mixture of DNA from two different males.
¶ 21
However, the record is to the contrary. The analyst testified
that she used a generally accepted scientific metric. Specifically,
she explained that when there is a mixture of two DNA types at a
particular location, the presence of at least three times the amount
of one type as the other type generally indicates that the type
present in the larger amount is the major contributor, and that this
three-to-one threshold for determining major and minor
contributors to a mixture sample was “a general rule of thumb [that
is] very commonly used across forensic labs.” See Shreck, 22 P.3d
at 77 (nonexhaustive list of factors courts may consider when
making reliability determinations under CRE 702 includes “whether
the technique has been generally accepted” (citing Daubert v. Merrell
Dow Pharm., Inc., 509 U.S. 579, 593-94 (1993))).
2. Y-STR Database Size
¶ 22
We also disagree that the allegedly small size of the database
used to generate the exclusion statistics rendered the statistics
9
unreliable.
¶ 23
Even when the underlying scientific evidence is reliable under
CRE 702, a separate CRE 702 analysis “is independently necessary
to show that statistical or numerical results are also . . . reliable.”
People v. Wilkerson, 114 P.3d 874, 877 (Colo. 2005); see Shreck, 22
P.3d at 77. Our examination of the record reveals no abuse of
discretion in the trial court’s determination that the exclusion
statistics were reliable.
¶ 24
In her testimony, the analyst explained how she used the
counting method to generate the Y-STR exclusion statistics. She
testified that she first determined that defendant’s Y-STR profile
matched the partial profile observed from the inner thigh sample.
Next, she looked for that same partial profile in the YFiler database
of 3,561 individuals’ Y-STR profiles. After determining how often
that partial profile occurred in the database, she applied a 95%
confidence value to the results and concluded that, while defendant
could not be excluded as the source of the DNA in the inner thigh
sample, 99.6% of African Americans, 99% of Caucasians, and
99.5% of Hispanics could be excluded. The analyst testified that
the statistical methods she used were “general statistical methods
10
that are used in several different fields,” that “[o]ther laboratories
use the same methods,” and that “the size of the database, which at
this point is about 3,500 people . . . is commonly used.”
¶ 25
In addition, the trial court considered decisions from other
jurisdictions that have upheld as reliable the counting method in
general, as well as its use with the specific YFiler database at issue
here. See State v. Calleia, 997 A.2d 1051, 1064 (N.J. Super. Ct.
App. Div. 2010) (Y-STR testing, including use of same YFiler
database at issue here, generally accepted in the scientific
community and therefore admissible), rev’d on other grounds, 20
A.3d 402 (N.J. 2011); State v. Bander, 208 P.3d 1242, 1255 (Wash.
Ct. App. 2009) (hearing on use of counting method in Y-STR
analysis unnecessary, in part, because it is generally accepted in
scientific community (citing Frye v. United States, 293 F. 1013 (D.C.
Cir. 1923)).
¶ 26
Thus, we conclude that the court acted within its discretion by
determining that the scientific principles underlying the use of the
YFiler database with the counting method to generate the exclusion
statistics were reliable. Specifically:
• There was testimony that the statistical methods used were
11
generally accepted by other laboratories. See Shreck, 22 P.3d
at 77 (courts may consider “whether the technique has been
generally accepted” when making reliability determinations
under CRE 702 (citing Daubert, 509 U.S. at 593-94)).
• There was testimony that similar statistical methods were
used in several other fields. See id. at 77-78 (courts may
consider “the non-judicial uses to which the technique are
put” when making reliability determinations under CRE 702
(citing United States v. Downing, 753 F.2d 1224, 1238-39 (3d
Cir. 1985))).
• Other jurisdictions have admitted similar evidence as reliable.
See id. (courts may consider “whether such evidence has been
offered in previous cases” when making reliability
determinations under CRE 702 (citing Downing, 753 F.2d at
1238-39)).
3. Amount of DNA
¶ 27
Defendant also challenges the Y-STR evidence as unreliable
because it was obtained from an amount of DNA that, according to
defendant, was too small. Again, we disagree.
¶ 28
The analyst testified that the Y-STR evidence from the inner
12
thigh sample was generated from a DNA sample of .3 nanograms.
The manufacturer of the kit used here recommended that analysts
use between .5 and 1 nanogram of DNA. The analyst testified that
using less than .5 nanograms may preclude obtaining an
interpretable profile. However, she also testified that, based on
CBI’s own validation studies, if an interpretable partial profile can
be obtained from an amount of DNA less than .5 nanograms, as it
was here, the reliability of the partial profile will not be affected.
¶ 29
At the Shreck hearing, defendant unsuccessfully attempted to
qualify as an expert a witness who would have testified that using
less than .5 nanograms of DNA diminishes the reliability of the
resulting profile. Although defendant made an offer of proof in the
trial court, he does not argue on appeal that the court erred by
refusing to qualify his witness. Consequently, the court heard, and
was entitled to rely on the unrefuted evidence that using less than
.5 nanograms did not affect the reliability of the DNA analysis. See
Shreck, 22 P.3d 68, 82 (once evidence deemed admissible,
additional challenges to its reliability go to weight); see also People
v. Gillis, 883 P.2d 554, 559 (Colo. App. 1994) (an offer of proof is not
evidence but shows what counsel expects to prove by the excluded
13
evidence); cf. Hudson v. Park Dev. Co., 493 P.2d 379, 381 (Colo.
App. 1972) (not published pursuant to C.A.R. 35(f)) (“The weight to
be accorded expert testimony is within the sound discretion of the
trier of fact and will not be disturbed on review in the absence of an
abuse of that discretion.”).
II. Sleeping Juror
¶ 30
Defendant contends that the court erred by releasing a juror
who repeatedly fell asleep, and replacing him with an alternate
juror. We review for abuse of discretion, which, in this context,
means a ruling that is “manifestly arbitrary, unreasonable, or
unfair.” People v. Lee, 30 P.3d 686, 690-91 (Colo. App. 2000) (citing
Jurgevich v. Dist. Court, 907 P.2d 565 (Colo. 1995)). We see no
abuse of discretion here.
¶ 31
Although defendant is entitled to a trial by fair and impartial
jurors, he is not entitled to any particular juror. People v. Johnson,
757 P.2d 1098, 1100 (Colo. App. 1988) (citing People v. Tippett, 733
P.2d 1183 (Colo. 1987)). Moreover, a trial court “shall replace
jurors who, prior to the time the jury retires to consider its verdict,
become unable or disqualified to perform their duties.” § 16-10105, C.R.S. 2011. To obtain relief as the result of a court’s
14
releasing and replacing a juror, the defendant must show that the
remaining jurors were unfair or biased, or that he was actually
prejudiced by the dismissal and replacement of the original juror.
See Johnson, 757 P.2d at 1100. An appellate court will not assume
prejudice. See id.
¶ 32
During trial, the court noticed that one of the jurors seemed to
be having trouble staying awake. The court stated, “[I]t is
observable that his head falls. He appears not to be awake.” When
the court indicated that it was inclined to release the sleeping juror,
defense counsel requested that the court question the juror about
whether he was sleeping. The court did so, and the juror indicated
that he was having trouble staying awake and admitted to nodding
off during the trial. The court then released the juror and replaced
him with an alternate. Defendant moved for a mistrial based on
being denied a jury of his choice, and the court denied the motion.
¶ 33
The court’s decision to replace the sleeping juror was not an
abuse of discretion. See Lee, 30 P.3d at 691 (decision to dismiss
juror who had been victim of juror intimidation not an abuse of
discretion because the court gave valid reasons for dismissal);
compare People v. Evans, 710 P.2d 1167, 1168 (Colo. App. 1985)
15
(court abused its discretion by failing to replace juror with alternate
where court knew that juror was sleeping during closing argument),
with People v. King, 121 P.3d 234, 241-42 (Colo. App. 2005) (court
did not abuse its discretion by failing to replace juror with alternate
because there was not sufficient evidence to show that he was
sleeping during the trial).
¶ 34
Nonetheless, defendant contends that he was prejudiced
because the alternate juror was biased in favor of DNA evidence.
For support, defendant relies on an equivocal statement made by
the alternate juror during voir dire that he may have “some sort of
bias, either positively or negatively” about DNA evidence. However,
the alternate juror went on to say that he “would make every effort
to be fair and impartial.” Thus, in the absence of any other
assertion of bias, the trial court was well within its discretion to
dismiss the sleeping juror and to replace him with the alternate
juror. See People v. Woellhaf, 87 P.3d 142, 151 (Colo. App. 2003)
(court within its discretion to deny challenge for cause to juror who
expressed doubt about the defendant’s innocence, but indicated
“that she would try to put her biases aside,” would “want to listen to
the evidence,” and “thought she could be fair”), rev’d on other
16
grounds, 105 P.3d 209 (Colo. 2005); People v. Griffin, 985 P.2d 15,
20-21 (Colo. App. 1998) (court within its discretion to deny
challenge for cause to juror who expressed concerns about ability to
be fair, but stated that “he would try his best and would be as fair
as he could”).
III. Sexually Violent Predator
¶ 35
The supreme court granted certiorari on the issue of
“[w]hether the determination that petitioner is a sexually violent
predator based upon the criterion that he ‘promoted a relationship
primarily for the purpose of sexual victimization’ was appropriate
given that the evaluators relied solely upon the actual assault.”
Then it remanded to this court for reconsideration in light of People
v. Gallegos, 2013 CO 45. On remand, the parties submitted
supplemental briefs concerning Gallegos. After considering those
briefs and based on Gallegos, we conclude that the trial court’s
determination that defendant is a sexually violent predator within
the meaning of section 18-3-414.5(1)(a)(III), C.R.S. 2013, must be
set aside.
¶ 36
Section 18-3-414.5(2) directs the trial court to issue an order
concerning whether the defendant is a sexually violent predator
17
“[b]ased on the results of the [screening instrument].” The evidence
must support those results. See People v. Cook, 197 P.3d 269, 281
(Colo. App. 2008) (affirming trial court’s designation of the
defendant as sexually violent predator because the “evidence
supports the screening [instrument] and, therefore, the findings and
ruling by the trial court”). We review a court’s factual findings for
clear error, but review de novo whether those findings are sufficient
to support the legal conclusion that defendant is a sexually violent
predator. See People v. Tuffo, 209 P.3d 1226, 1230 (Colo. App.
2009).
¶ 37
As relevant here, the sexually violent predator designation
applies to an offender “[w]hose victim was . . . a person with whom
the offender established or promoted a relationship primarily for the
purpose of sexual victimization.” § 18-3-414.5(1)(a)(III). When a
defendant is convicted of an offense to which the designation
potentially applies, the probation department shall complete the
sexually violent predator risk assessment screening instrument.
§ 18-3-414.5(2), C.R.S. 2013. Based on the results of the screening
instrument, the trial court shall make specific findings of fact and
enter an order concerning whether the defendant is a sexually
18
violent predator. Id.
¶ 38
Here, at the end of the sentencing hearing, the trial court
found that defendant was a sexually violent predator because he
had promoted a relationship with the victim primarily for the
purpose of sexual victimization. It explained that defendant met
“the criteria of promoted a relationship . . . under the [screening
instrument]” by:
waiting until the middle of the night, going into
someone’s house, breaking in when to [sic]
know no one else is there. Taking steps to
make sure to facilitate the commission of the
sexual assault.
¶ 39
However, because section 18-3-414.5 “does not grant the
SOMB the authority to define” the phrases “‘established a
relationship’” or “‘promoted a relationship,’” Gallegos, ¶ 10, we must
disregard the two-step inquiry and underlying criteria identified in
the screening instrument. Instead, we examine the court’s findings
and the testimony at the sentencing hearing using the definition in
Gallegos, ¶ 14 (a defendant “‘promoted a relationship’” with the
victim if “excluding the offender’s behavior during the commission of
the sexual assault that led to his conviction, he otherwise
encouraged a person with whom he had a limited relationship to
19
enter into a broader relationship primarily for the purpose of sexual
victimization”) (emphasis added).
¶ 40
At the sentencing hearing, the evaluators explained that before
going to the victim’s house on the night of the assault, defendant
had asked a local bartender whether the victim’s husband was
home. This query, followed shortly thereafter by the assault,
supports the finding that defendant took steps to facilitate
commission of the assault. However, such planning did not
encourage the victim “to enter into a broader relationship primarily
for the purpose of sexual victimization.” (The same would be true of
the Attorney General’s assertion that defendant planned the crime
by asking the victim’s husband, again some time before the assault,
how to handle the couple’s large dogs.)
¶ 41
Otherwise, the evaluators relied on the circumstances of the
assault, as do the remainder of the court’s findings. But this is now
precluded by the “during the commission of the sexual assault”
exclusion in Gallegos.
¶ 42
Nevertheless, the Attorney General’s supplemental brief
asserts that defendant sought to broaden the relationship with the
victim when, “a few months before the crime,” he “arrived at the
20
victim’s house by himself with a baby blanket made by his
grandmother after the victim’s son was born.” This assertion is
unpersuasive because the nature of the gift does not support the
Attorney General’s assertion that defendant was “placating the
victim with gifts to earn her trust.” And the passage of significant
time before the crime occurred, makes inferring that defendant
acted to broaden the relationship “primarily for the purpose of
sexual victimization” speculation.
¶ 43
These conclusions are informed by the examples in People v.
Tixier, 207 P.3d 844, 848 (Colo. App. 2008), cited with approval in
Gallegos, ¶ 15, where the division explained that “promoted” would
be shown if the offender:
encouraged the victim to be with him or her
more often and away from the usual place of
their limited relationship, and if the offender
encouraged the victim to participate in
activities not otherwise included in the limited
relationship . . . .
Here, regardless of defendant’s intent, the gift did not have either
effect on the victim’s behavior toward him.
¶ 44
Alternatively, the Attorney General asks that, if we “decide that
the trial court’s factual findings were not sufficient to support the
21
SVP designation, the case should be remanded for [sic] the trial
court for findings in light of the recent changes in the law.”
However, the citation of Gallegos to support this request is
misplaced. There, the supreme court remanded to this court with
instructions to remand to the trial court for findings on “promoted a
relationship” because the trial court had not made any findings on
this criterion, having relied solely on the “established a relationship”
criterion. Gallegos, ¶ 18. Here, the trial court did the converse: it
addressed “promoted a relationship,” but did not address
“established a relationship.” Thus, no purpose would be served by
remanding for further findings.
¶ 45
Therefore, we conclude that the sexually violent predator
portion of defendant’s sentence must be vacated.
¶ 46
The case is remanded to the trial correct for correction of the
mittimus to remove the designation of defendant as a sexually
violent predator. The judgment and sentence are otherwise
affirmed.
CHIEF JUDGE LOEB and JUDGE PLANK concur.
22
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