IN THE
SUPREME COURT OF THE STATE OF ARIZONA
STATE OF ARIZONA,
Appellee,
v.
CHRIS THOMAS GOMEZ
Appellant.
No. CR-19-0292-PR
Filed March 9, 2021
Appeal from the Superior Court in Pima County
The Honorable Bryan B. Chambers, Judge
No. CR20163385-001
Memorandum Decision of the Court of Appeals
Division Two
No. 2 CA-CR 18-0052
Filed August 8, 2019
VACATED AND REMANDED
COUNSEL:
Mark Brnovich, Arizona Attorney General, Brunn (Beau) W. Roysden III,
Solicitor General, Linley Wilson, Chief Counsel, Phoenix, Kathryn A.
Damstra (argued), Assistant Attorney, Criminal Appeals Section, Tucson,
Attorneys for State of Arizona
Richard C. Bock, Law Office of Richard C. Bock, Harley D. Kurlander
(argued), Law Office of Harley Kurlander, Tucson, Attorneys for Appellant
Daniel A. Arellano, Ballard Spahr, LLP, Phoenix, Yalda Godusi, Lewis Roca
Rothgerber & Christie, LLP, Phoenix, Attorneys for Amicus Curiae Arizona
Attorneys for Criminal Justice
STATE OF ARIZONA V. CHRIS THOMAS GOMEZ
Opinion of the Court
________________
JUSTICE BOLICK authored the opinion of the Court, in which CHIEF
JUSTICE BRUTINEL, VICE CHIEF JUSTICE TIMMER, and JUSTICES
GOULD, LOPEZ, BEENE, and MONTGOMERY joined.
_______________
JUSTICE BOLICK, opinion of the Court:
¶1 Defendant Chris Gomez was convicted of sexual assault. The
court of appeals reversed the conviction on the ground that DNA evidence
was improperly admitted because it was insufficient to identify anyone and
was therefore unfairly prejudicial. As the evidence was not used to
establish identity but to demonstrate that a man other than the victim’s
husband touched the victim’s genitals, we hold it was properly admitted
and therefore vacate the court of appeals’ decision. We remand the case to
that court to consider an unresolved issue.
BACKGROUND
¶2 Early one morning in July 2016, the victim, J.B., was driving
for Uber and picked up Gomez, who had requested a ride. Gomez sat in
the front passenger seat as J.B. drove him to an apartment complex.
According to J.B., as they were completing the trip, Gomez grabbed her
wrist, pulled her toward him, and restrained her. Gomez pushed her bra
and dress down, and kissed her face, neck, and breast. J.B. told him to stop
and scratched him, to no avail. Gomez pulled up her dress and put his
fingers in her vagina. She managed to push him away and get out of the
van. J.B. demanded that Gomez leave the van, and after trying to coax her
back inside, he complied. As Gomez walked toward her, J.B. got back
inside the van and locked the doors. Gomez started knocking on the
window, telling J.B. he wanted to talk about what happened, but she drove
off.
¶3 J.B. called her husband, R.R., and told him what had
happened. He told her to go somewhere safe, and she drove to a gas station,
where she called 911. After J.B. spoke to responding officers, she went to a
nearby hospital, where nurses performed a sexual assault examination,
2
STATE OF ARIZONA V. CHRIS THOMAS GOMEZ
Opinion of the Court
collecting DNA samples from her face, neck, chest, breasts, fingernails,
vagina, and external genital areas.
¶4 Uber identified Gomez as the passenger. Gomez also
messaged J.B. through the Uber application, saying, “Sorry about all that.
Way out of line.” However, during Gomez’s initial interview with the
police, he contended that “nothing happened” and he “never touched” J.B.
A grand jury indicted Gomez on one count of sexual assault for “placing
his finger(s) in her vagina.”
¶5 A DNA analyst matched Gomez’s DNA profile with samples
taken from J.B.’s face, neck, chest, and breasts but could neither include nor
exclude Gomez as a contributor to the DNA found under J.B.’s fingernails.
Using a Y-STR (short tandem repeat) technique, the analyst examined DNA
samples from J.B.’s vagina and external genitals for Y (male) chromosomes.
Those tests found a “full profile” for R.R., with whom J.B. confirmed she
had sex earlier in the day. On the external genital swabs, the analyst also
found a minor DNA profile, consisting of “two additional male DNA
markers or . . . [a]lleles” that were contained in Gomez’s DNA profile.1
Because there were only two markers and the rest of the minor DNA profile
was absent, the analyst could not match the DNA to any particular person’s
profile but was able to conclude that it belonged to a male who was not R.R.
Thus, the minor Y-DNA profile on the external genital swabs was
“inconclusive” as to the contributor’s identity.
¶6 Before trial, Gomez filed a motion in limine to preclude any
testimony about the minor Y-DNA profile on the external genital swabs.
He argued the evidence was inadmissible under Arizona Rules of Evidence
401 and 702, contending that it was irrelevant because it was insufficient to
identify Gomez or to run a statistical probability and could confuse the jury.
The trial judge (citing Daubert v. Merrell Dow Pharms., Inc., 509 U.S. 579
(1993)) found that Gomez “would not be prejudiced by the jury hearing an
inconclusive DNA result. The DNA results pass Daubert and the Court
takes note of defense counsel’s argument as to relevancy; however,
precluding this specific DNA result from the jury may cause the jury to
speculate.” Thus, the court ruled the evidence admissible, subject to cross-
1 “DNA’s component parts include base pairs that determine genetic traits,
called alleles.” State v. Bigger, 227 Ariz. 196, 206 ¶ 33 n.17 (App. 2011).
3
STATE OF ARIZONA V. CHRIS THOMAS GOMEZ
Opinion of the Court
examination, but precluded the State from arguing that “this particular
result of the DNA test shows that [Gomez’s] DNA was there.” The court
added that if the State “infer[s] anything more than that, there might be a
curative instruction.”
¶7 During trial, Gomez testified that when he and J.B. arrived at
the apartment complex, they continued talking and he kissed her lips, neck,
chest, and breasts, all of which was consensual. She then pulled away and
told him that she was in a relationship. Gomez specifically denied that he
placed his fingers in J.B.’s vagina or did anything that was not consensual.
¶8 The DNA analyst testified at trial that the major Y-DNA
profile matched R.R. She also testified about the minor Y-DNA profile,
stating that the two markers were insufficient to make any sort of
comparison and were therefore inconclusive. Gomez objected, arguing that
the State was drawing an inference that the court had forbidden in response
to the motion in limine. The objection was overruled. The analyst then
testified that the two alleles were within Gomez’s profile but that they were
insufficient for identification and therefore inconclusive. The analyst had
earlier testified that the markers could belong to any male other than R.R. 2
¶9 During closing argument, the State noted that there were two
DNA “outliers” on J.B.’s external genitals that belonged to a male other than
R.R. The State acknowledged that they were inconclusive as to identity and
that only J.B. could identify who left the DNA there. Gomez requested a
mistrial based on that part of the closing argument, which the court denied.
The jury convicted Gomez as charged and he was sentenced to 5.75 years
in prison.
¶10 A divided court of appeals reversed. The majority concluded
that the minor Y-DNA evidence offered during trial was relevant under
Rule 401. State v. Gomez, No. 2 CA-CR 2018-0052, 2019 WL 3761642, at *6
2 Presumably some other males, in addition to R.R., lack the same two
alleles. However, the State did not make this point, as it did not use the
alleles to identify Gomez as the perpetrator.
4
STATE OF ARIZONA V. CHRIS THOMAS GOMEZ
Opinion of the Court
¶¶ 27–28 (Ariz. App. Aug. 08, 2019) (mem. decision). 3 The court also found
that the analyst’s expert testimony was “helpful,” as it “bore on the question
of Gomez’s guilt—albeit circumstantially.” Id. ¶ 29. But the majority was
concerned that “the analyst could not provide any statistical data regarding
the number of people who would have had those two alleles in their
profile.” Id. at *7 ¶ 33. Thus, the majority concluded that “the minimal
probative value of the evidence concerning the matching two alleles was
substantially outweighed by a danger of unfair prejudice and confusion”
and was therefore inadmissible under Rule 403. Id. at *8 ¶ 34 (citing Ariz.
R. Evid. 403). Because the error was not harmless, the court reversed
Gomez’s conviction and sentence. Id. at *10 ¶ 44.
¶11 Agreeing with the majority that the evidence was relevant,
the dissent observed that “[w]e ought to be loath to find prejudice when the
trial court, much closer to the question, found none.” Id. at *12 ¶ 51
(Brearcliffe, J., dissenting). The dissent concluded that “there was no risk
of confusion under Rule 403 that could not be ameliorated by cross-
examination. Further, the court expressly barred the state from raising any
inference that the testing positively identified the minor Y-DNA evidence
as Gomez’s DNA, and the state did not do so.” Id. ¶ 52.
¶12 We granted review on the question of whether the trial court
committed reversible error by admitting expert testimony that inconclusive
DNA evidence found on the victim had two alleles also present in the
defendant’s DNA profile. The use of DNA evidence in criminal
prosecutions is a recurring issue of statewide concern. We have jurisdiction
under article 6, section 5 of the Arizona Constitution and A.R.S. § 13-4036.
DISCUSSION
¶13 We review a trial court’s decision whether to admit DNA
evidence for an abuse of discretion and in the light most favorable to
3 Because the court reversed the conviction based on improper trial
testimony, it did not reach the dispute over closing arguments. Id. at *3 ¶ 15
n.4. For the sake of finality, and because the issues are essentially the same
and the parties argued them in their entirety, our decision encompasses the
closing arguments, so there is no need for remand on this issue.
5
STATE OF ARIZONA V. CHRIS THOMAS GOMEZ
Opinion of the Court
sustaining its ruling. State v. Escalante-Orozco, 241 Ariz. 254, 273 ¶ 44 (2017),
abrogated on other grounds by State v. Escalante, 245 Ariz. 135 (2018). We
review interpretation and application of our evidence rules de novo. State
v. Fitzgerald, 232 Ariz. 208, 210 ¶ 10 (2013).
¶14 Rule 403 provides in pertinent part: “The court may exclude
relevant evidence if its probative value is substantially outweighed by a
danger of one or more of the following: unfair prejudice, confusing the
issues, [or] misleading the jury . . . .” Ariz. R. Evid. 403. One verb and one
adverb in that provision are especially important to our analysis. First, if
the standard is met, the court “may” exclude relevant evidence. The term
“may” indicates discretion. State v. Lewis, 224 Ariz. 512, 515 ¶ 17 (App.
2010), aff’d, 226 Ariz. 124 (2011); In re Marquardt, 161 Ariz. 206, 210 (1989).
Second, the relevant evidence may be excluded if its probative value is
“substantially” outweighed by one of the listed dangers.
¶15 The conditions of admission of DNA evidence and expert
testimony, particularly from the standpoint of Rule 403 prejudice, are
necessarily fact-specific and dependent upon the context of the case. That
is why we rely so heavily upon, and defer so extensively to, the discretion
of the trial court, which is in a far better position than an appellate court to
weigh potential prejudice in the overall context of the case. See, e.g., State v.
Rodriguez, 186 Ariz. 240, 250 (1996).
¶16 In this case, the DNA evidence was not used to establish
identity. Gomez’s own testimony, along with a host of other evidence,
established that Gomez was in the front seat of the vehicle with J.B. and
kissed her face, neck, chest, and breasts. An essential element in
determining whether sexual assault was committed was whether Gomez
touched her genitals, which the State alleged and Gomez denied. Under
those circumstances, DNA evidence that only established that a man other
than J.B.’s husband touched her genitals was probative on that issue, and
indeed the court of appeals properly concluded both that the evidence was
relevant and that the expert’s testimony was helpful. Gomez, 2019 WL
3761642, at *6 ¶¶ 27–29.
¶17 The trial judge carefully circumscribed how the evidence
could be presented such that it would not prejudice the defendant or
confuse or mislead the jury by suggesting more than the DNA sample could
6
STATE OF ARIZONA V. CHRIS THOMAS GOMEZ
Opinion of the Court
demonstrate. Specifically, he ruled that “the State is not permitted to argue
to the jury that this particular result of the test show[s] that the Defendant’s
DNA was present.” The judge further provided that if the State went
beyond that, Gomez could cross-examine the expert witness and present
contrary evidence, and that the court would provide a curative jury
instruction if necessary.
¶18 The prosecutor and expert witness adhered scrupulously to
those boundaries. The witness repeatedly testified that the results were
“inconclusive,” meaning they could not be used at all to identify anyone.
Although she indicated that the minor Y-DNA profile was consistent with
Gomez’s, she did not suggest there was a DNA “match,” nor, as the court
of appeals observed, Gomez, 2019 WL 3761642, at *5 ¶ 22 & n.6, did she
testify that Gomez was “not excluded” as a DNA contributor. See, e.g., State
v. Johnson, 247 Ariz. 166, 200–01 ¶¶ 134–37 (2019) (holding that the term
“match” may be used where a very strong statistical probability links
defendant to DNA found at a crime scene); Escalante-Orozco, 241 Ariz. at
274 ¶¶ 49–50 (allowing the terms “not excluded” and “match” so long as
they are not “likely to mislead jurors to believe [defendant] was the source
of the profile rather than a possible source”).
¶19 In closing argument, the prosecutor emphasized the limited
yet crucial role played by the DNA evidence. She noted that the major DNA
contributor was J.B.’s husband. As to the minor Y-DNA sample, the
prosecutor stated it “is inconclusive for comparison purposes. There is not
enough for [the expert] to say and there never will be.” She then explained,
“What does inconclusive mean? What did [the expert] tell us? You can’t
say anything about it. You can’t say whether someone’s included or
excluded. There’s simply not enough.” Moreover, the prosecutor noted
that in cross-examination, defense counsel asked the expert, “[S]o it could
be anyone in the world and we just don’t know? She said, yeah, it’s true.
But when we look at the evidence in this case, who can tell us who the other
male was?”
¶20 At that point, the defendant requested a mistrial. After that
was denied, the prosecutor summed up the point of the DNA evidence.
“[T]he one person who can tell us the other male DNA that’s present on her
external genitalia swab was [J.B.],” she argued. “It’s not the DNA evidence
because that’s inconclusive. But you don’t have to take things in a vacuum
7
STATE OF ARIZONA V. CHRIS THOMAS GOMEZ
Opinion of the Court
when you decide this case. You decide this case based on the totality of the
circumstances, absolutely everything you’ve heard in this courtroom.”
¶21 The court of appeals divided the minor Y-DNA evidence into
two categories. It concluded that the “minor Y-DNA profile on the external
genital swabs was probative evidence showing that another male had
touched J.B.” and could not “say the trial court clearly abused its discretion
by concluding the probative value of that part of the DNA evidence was
[not] substantially outweighed by a danger of unfair prejudice or
misleading the jury.” Gomez, 2019 WL 3761642, at *7 ¶ 31.
¶22 However, the court decided that the testimony “concerning
the two alleles found in the minor Y-DNA profile and Gomez’s profile” was
excessively prejudicial or confusing for two distinct but related reasons. Id.
at *7–8 ¶¶ 32, 34. First, “testing of the external genital swabs established an
‘inconclusive’ minor Y-DNA profile, yet the analyst stated that the two
alleles from the minor profile were consistent with Gomez’s profile in terms
of their numbers and locations.” Id. at *7 ¶ 33. Second, “the analyst could
not provide any statistical data regarding the number of people who would
have had those two alleles in their profile,” thus rendering the allele
testimony inadmissible under Rule 403. Id.
¶23 The court based its holding that such evidence was
insufficiently probative and excessively prejudicial on State v. Fulminante,
193 Ariz. 485 (1999). Gomez, 2019 WL 3761642, at *7 ¶ 32. In Fulminante, the
Court excluded on Rule 403 grounds inconclusive DNA evidence that the
expert concluded was negative as to whether a sexual assault had been
committed. The Court reasoned that “[i]f the state’s expert was forthright
enough to say that the findings were so inconclusive he had to reach a
negative conclusion, then admitting the evidence so that the jury could
reach a different conclusion merely invited the jury to speculate and posed
a serious threat of misleading.” Fulminante, 193 Ariz. at 504 ¶ 67.
¶24 We disagree with the court of appeals’ approach. First,
contrary to its analysis, the State did not separate the minor Y-DNA profile
genital swab evidence from the alleles but rather presented the evidence as
a coherent whole, establishing the sole fact that a male other than J.B.’s
husband had touched her genitals. The evidence was only used to exclude
R.R., not to identify any possible individuals who might have left the alleles.
8
STATE OF ARIZONA V. CHRIS THOMAS GOMEZ
Opinion of the Court
¶25 Moreover, Fulminante is inapposite because it involved a
murder in which sexual assault was not charged; hence, the DNA evidence
was not probative. Id. And unlike Fulminante, here the DNA evidence and
the expert’s testimony were not inconsistent. To the contrary, as the expert
and prosecutor repeatedly emphasized, the inconclusive DNA evidence
could have come from any male other than R.R. The alleles could not
establish, or even imply, the identity of the DNA contributor; that could
only come from J.B.’s testimony and circumstantial evidence.
¶26 We reject for similar reasons the court of appeals’ reasoning
that the allele testimony was inadmissible under Rule 403 because it was
not accompanied by statistical evidence showing the likelihood that Gomez
was the DNA source. All the cases cited in support of this proposition by
Gomez and the court of appeals involve the use of DNA to identify a
suspect, which is markedly different from the limited purpose for which
the allele testimony was presented here.
¶27 The court of appeals acknowledged that this Court “has
suggested that statistical evidence is not always necessary in quantifying
DNA results.” Gomez, 2019 WL 3761642, at *5 ¶ 24 (citing State v. Boles, 188
Ariz. 129, 132 (1997) and State v. Hummert, 188 Ariz. 119, 124 (1997) for the
proposition that expert DNA testimony may be supported by personal
experience). Despite those rulings, however, the court of appeals
concluded such statistics were required here, noting that other jurisdictions
have required statistical analysis as a prerequisite for presenting DNA
evidence. Id. at *6 ¶ 25 (citing People v. Coy, 620 N.W.2d 888, 899 (Mich. Ct.
App. 2000)).
¶28 But when a sample is inconclusive, the expert cannot quantify
the likelihood that it matches a specific person. State v. Bander, 208 P.3d
1242, 1245 ¶ 9 (Wash. Ct. App. 2009). Had the expert been required to
present statistical probability, presumably she would have had to testify
that, by the inconclusive allele evidence alone, there was an incalculable
possibility that the DNA belonged to Gomez. A categorical rule that
statistical probabilities are necessary to introduce DNA evidence would
therefore necessarily preclude the use of inconclusive DNA evidence
altogether.
9
STATE OF ARIZONA V. CHRIS THOMAS GOMEZ
Opinion of the Court
¶29 This Court has emphasized that “there is no single or specific
scientific method” of introducing DNA evidence, “but, rather, different
ways of explaining the significance in a forensic setting.” Hummert, 188
Ariz. at 124. Depending on the totality of the circumstances, it is
permissible to use DNA evidence in a carefully limited way when “the jury
[can] readily understand th[e] limitation.” Escalante-Orozco, 241 Ariz. at
273–74 ¶ 48.
¶30 Coy and other cases that require a showing of statistical
probability as a prerequisite for introducing DNA evidence involve the use
of such evidence to show that it is likely that the defendant committed the
crime. Here, in stark contrast, the DNA evidence was not used to prove
identity but a fact: specifically, that a crime was committed. Indeed, the
expert could only identify one man, R.R., as not being the person who
touched J.B.’s genitals. But with this limited use of the allele evidence to
demonstrate that a man other than her husband touched J.B.’s genitals, the
State was able to corroborate J.B.’s testimony (and discredit Gomez’s),
showing circumstantially that it was more likely that the man who was in
the car and who kissed and touched her also placed his fingers in her
vagina.
¶31 Put another way, the State did not need the allele evidence to
identify Gomez. That evidence did not show that Gomez was the person
who touched J.B.’s genitals. Instead, the prosecutor emphasized in closing
argument that the identity of the man who left the DNA on J.B.’s genitals
would have to be determined from other evidence. The DNA evidence
corroborates J.B.’s testimony that Gomez touched her genitals.
¶32 This limited use of inconclusive DNA evidence to establish
that a crime occurred does not raise the concerns implicated by Rule 403.
Its probative value for the limited purpose is high. See Gomez, 2019 WL
3761642, at *12 ¶ 54 (Brearcliffe, J., dissenting) (evidence consisted of
“confirmed male DNA which, in part, matched Gomez, but did not match
her [husband], and was where, in essence, the victim said it would be”).
That limited use also reduces its prejudicial impact, because the DNA
evidence is used only to show that someone other than R.R. touched J.B.’s
genitals. If the allele evidence was the only proof the State had that Gomez
sexually assaulted J.B., he would go free. Gomez’s identity had to be
established by other evidence. At the same time, without the allele
10
STATE OF ARIZONA V. CHRIS THOMAS GOMEZ
Opinion of the Court
evidence, which the court of appeals correctly held was competent to
establish that a sexual assault occurred, the case largely would come down
to a he-said, she-said dispute. And as the trial court observed, jurors would
have had to speculate about whether DNA evidence existed that J.B.’s
genitals were touched.
¶33 Given the careful presentation of the testimony, the
opportunity for cross-examination, and the State’s characterization of the
testimony during closing argument, the evidence was neither unfairly
prejudicial to Gomez nor confusing to the jury. See Escalante-Orozco, 241
Ariz. at 275 ¶ 59 (no Rule 403 violation because the “jury could understand
the limited probative value of the DNA evidence without danger of
confusion”). The State was entitled to present as full a picture as possible
without exaggerating or drawing undue conclusions. When “an expert’s
scientific testimony rests upon good grounds, . . . it should be tested by the
adversary process—competing expert testimony and active cross-
examination—rather than excluded from jurors’ scrutiny for fear that they
will not grasp its complexities or satisfactorily weigh its inadequacies.”
State v. Bernstein, 237 Ariz. 226, 230 ¶ 18 (2015) (citation omitted) (internal
quotation marks omitted).
¶34 It was certainly within the trial court’s broad discretion to
admit the allele testimony for the specified limited purpose of showing that
a crime occurred. The court carefully circumscribed the testimony to that
purpose, and the prosecutor hewed to that purpose in her closing remarks.
We find no error.
DISPOSITION
¶35 The court of appeals did not resolve the issue of whether a
detective’s response to a question at trial constituted fundamental error.
Gomez, 2019 WL 3761642, at *10 ¶ 44 n.10. We therefore remand to that
court to resolve this remaining issue and otherwise vacate its memorandum
decision.
11