State v. Yepez

                                                          Office of the Director        New Mexico
                                                           07:51:41 2021.03.30          Compilation
                                                                         '00'06-        Commission


            IN THE SUPREME COURT OF THE STATE OF NEW MEXICO

Opinion Number: 

Filing Date: February 25, 2021

No. S-1-SC-37216

CONSOLIDATED WITH

No. S-1-SC-37217

STATE OF NEW MEXICO,

      Plaintiff-Petitioner/Cross-Respondent,

v.

ANTHONY BLAS YEPEZ,

      Defendant-Respondent/Cross-Petitioner.

ORIGINAL PROCEEDING ON CERTIORARI
Mary Marlowe Sommer, District Judge

Released for Publication April 6, 2021.

Hector H. Balderas, Attorney General
Maris Veidemanis, Assistant Attorney General
Santa Fe, NM

for Petitioner/Cross-Respondent

L. Helen Bennett, P.C.
Linda Helen Bennett
Albuquerque, NM

for Respondent/Cross-Petitioner

                                          OPINION

NAKAMURA, Justice.

{1}   Defendant Anthony Blas Yepez (Yepez) was convicted of, among other crimes,
second-degree murder. At issue before this Court is the district court’s exclusion of
proposed expert testimony concerning Yepez’s alleged genetic predisposition to
impulsive violence—testimony Yepez offered on the issue of whether he had the
deliberate intent to kill. We hold that the district court did not abuse its discretion by
excluding the testimony. Accordingly, we reverse the Court of Appeals’ holding on this
issue, reject Yepez’s cross-appeal, and affirm his conviction.

I.      BACKGROUND

{2}   The relevant facts are undisputed and correctly summarized in the Court of
Appeals’ opinion, so we need not repeat them in detail here. State v. Yepez, 2018-
NMCA-062, ¶¶ 2-6, 

. Yepez and his girlfriend, Jeannie Sandoval
(Sandoval), lived with George Ortiz (Ortiz), the boyfriend of Sandoval’s adoptive mother.
On October 29, 2012, Yepez killed Ortiz during an argument, after which Yepez and
Sandoval set fire to Ortiz’s body. Id. ¶¶ 3-4. Ortiz’s autopsy concluded that his cause of
death was homicidal violence and thermal injuries, and that the manner of death was
homicide. Id. ¶ 6. The State charged Yepez with (1) first-degree murder, (2) conspiracy
to commit first-degree murder, (3) tampering with evidence, and (4) unlawful taking of a
motor vehicle.

A.      The Defense’s Proffered Expert Testimony

1.      Pretrial motions

{3}     Before trial, Yepez filed a motion in limine to admit expert testimony to the effect
that Yepez “experienced maltreatment in childhood” and has a genotype 1 that confers
low levels of monoamine oxidase A (MAOA)2 activity, which in combination produce
“maladaptive[] or violent[] behavior.” He emphasized that “[t]his testimony will serve as
almost the entire basis of [his] defense” to first-degree murder. One month later, Yepez
filed a so-called “Notice of Incapacity to Form Specific Intent,” stating his plan to call an
expert “on the issue of whether [Yepez] was incapable of forming the specific intent
required as an element of the crime charged,” namely, first-degree murder, and
referring to the proposed expert testimony on Yepez’s genetic predisposition to
violence. Yepez also filed an amended motion in limine clarifying that he was requesting
a hearing on the admissibility of this genetic evidence. Yepez identified a number of
potential experts in the foregoing motions, including a neuropsychologist, James S.
Walker, Ph.D., and a geneticist, David A. Lightfoot, Ph.D., whose report on Yepez’s
MAOA genotype was appended to the original motion in limine.

{4}   The State then filed its own motion in limine seeking to exclude the defense’s
proposed expert testimony. The State did not dispute the qualifications of the proffered

1“A genotype is an individual’s collection of genes. The term also can refer to the two alleles inherited for
a particular gene. The genotype is expressed when the information encoded in the genes’ DNA is used to
make protein and RNA molecules.” Nat’l Insts. of Health, Nat’l Human Genome Research Inst., Genotype
(Nov. 5, 2020), available at https://www.genome.gov/genetics-glossary/genotype (last visited Nov. 25,
2020).
2MAOA is an enzyme that exerts an effect on the metabolism of various neurotransmitters in the brain.
Avshalom Caspi et al., Role of Genotype in the Cycle of Violence in Maltreated Children, 297 Science
851, 851-54 (2002) (hereinafter the “Caspi study”), available at
http://local.psy.miami.edu/faculty/dmessinger/
c_c/rsrcs/rdgs/temperament/caspi2002.maltreatedgenotype.pdf (last visited Nov. 25, 2020).
experts but argued that the proposed evidence was not relevant or reliable under Rule
11-702 NMRA, Daubert v. Merrell Dow Pharmaceuticals, Inc., 

 (1993), and
State v. Alberico, 

, 

, 

. Specifically, the State
contended that the alleged predisposition to violence resulting from a low-activity MAOA
genotype and childhood maltreatment is not yet understood with sufficient precision to
be reliable or relevant as a predictor of violence in individuals. The State further argued
that Yepez’s self-reported childhood maltreatment was uncorroborated and self-serving.
Finally, the State contended that the proposed expert testimony would mislead and
confuse the jury due to the complexity of the testimony and the jury’s susceptibility to a
deterministic interpretation.

2.     Daubert/Alberico hearing

{5}    At the Daubert/Alberico hearing, Yepez presented the testimony of Walker, Rose
McDermott, Ph.D., a political scientist and psychologist with expertise in the behavioral
sciences, and Adrian Raine, Ph.D., a psychologist. All three witnesses based their
opinions on research purportedly supporting a relationship between childhood
maltreatment combined with low MAOA activity and predisposition to antisocial
aggressive behavior. Among the earliest research is a 1993 study from the Netherlands,
focusing on a family in which a genetic mutation resulted in a complete deficiency of
MAOA in certain males. H.G. Brunner et al., Abnormal Behavior Associated with a Point
Mutation in the Structural Gene for [MAOA], 262 Science 578, 578-80 (1993)
(hereinafter the “Brunner study”). 3 The study found a relationship between “isolated
complete deficiency of MAOA activity and abnormal aggressive behavior in affected
males.” Id. at 579-80. This complete deficiency of MAOA, characterized by impulsive
aggressive behavior, is known as “Brunner syndrome.”

{6}    This study was followed by the “classic” Caspi study in 2002, finding that
maltreated male children with a genotype conferring low levels of MAOA expression
were predisposed to develop antisocial behavior. See Caspi study, supra, at 851, 853.
Raine and Walker both testified that the Caspi findings have now been replicated in
numerous studies, citing a then-recent meta-analysis of twenty-seven peer-reviewed
studies by Amy L. Byrd and Stephen B. Manuck, MAOA, Childhood Maltreatment, and
Anti-Social Behavior: Meta-analysis of a Gene-Environment Interaction, 75 Biological
Psychiatry 9, 9-17 (2014) (hereinafter the “Byrd and Manuck study”). 4 The meta-analysis included a number of studies which had failed to replicate Caspi’s findings, but
concluded that the twenty-seven showed, “[a]cross male cohorts,” a “moderately reliable
interaction of MAOA variation and environmental risk factors, with childhood adversity
presaging antisocial outcomes more strongly in persons of low-activity, compared with
high-activity, MAOA genotype.” Id. at 14. McDermott also testified regarding her recent

3Available at https://ncbs.res.in/sitefiles/gb2012/Abnormal%20behavior%
20associated%20with%20a%20point%20mutation%20in%20the%20structural%20gene%20for%20mono
amine%20oxidase%20A.pdf (last visited Nov. 25, 2020).
4Available at
https://www.researchgate.net/publication/240308439_MAOA_Childhood_Maltreatment_and_Antisocial_B
ehavior_Meta-analysis_of_a_Gene-Environment_
Interaction (last visited Nov. 30, 2020).
experiment and report thereon, finding that participants maltreated as children who had
low-activity MAOA were more likely to want to punish a perceived aggressor relative to
participants with high-activity MAOA.

{7}     Walker conducted a forensic neuropsychological examination of Yepez and
requested genetic testing of Yepez as an aspect of that examination. In the
Daubert/Alberico hearing, Walker explained that he asked Lightfoot to look at Yepez’s
MAOA gene expression and “tell [him] whether or not Mr. Yepez had a low or high
activity of that gene.” Lightfoot’s report concluded that

       the deletion of the MAOA allele in [Yepez] encompasses one or both of
       the amplification sites. The size of the deletion cannot be determined
       without further experimentation. However, there can be no doubt that
       [Yepez] carries a rare mutation in the MAOA gene on [his] single X
       chromosome. . . . Outcomes to be predicted from an MAOA deletion
       would include aggressive behavior as characterized for Brunner’s
       syndrome . . . .

{8}     Walker opined, based on this report, that Yepez has “an extremely low function
of the [MAOA] gene,” though he conceded that “[w]e don’t know if Mr. Yepez really has
the Brunner syndrome, if he really has a no[-]activity gene.” Walker also testified that
Yepez credibly reported experiencing a “pretty horrific childhood” characterized by
significant abuse. When asked his opinion as to the implications of these findings,
Walker responded that Yepez “committed an act of impulsive, senseless violence in this
particular case,” and that Yepez’s “history of childhood abuse and . . . this low MAOA
activity gene made him exceptionally predisposed to committing violent behavior.”

{9}     After receiving evidence at the Daubert/Alberico hearing, the district court
identified the question it was being asked to decide as follows: “whether to allow
[Walker] to testify before the jury that—that [Yepez]—the fact that he has a history of
child abuse, a low MAOA activity gene made him exceptionally predisposed to
committing violent behavior.” The district court concluded—with respect to the
underlying science drawing connections between childhood maltreatment of males
having low levels of MAOA and increased violent behavior—that “in this case, the
Daubert factors were met.” The court went on, however, emphasizing that, under Rule
11-702 and Alberico, an expert opinion is not of assistance to the jury unless the
scientific technique or method upon which it is premised is reliable. Applying this
standard, the court stated, “I’m really kind of iffy on whether—whether we’ve satisfied—
whether it’s a scientific technique that’s reliable enough to prove what it [purports] to
prove,” observing that the thirty-year longitudinal study referenced in periodicals that the
defense provided to the court was “inconclusive” and that there is still “work to be done.”

{10} The district court then came to its overall conclusion and said, “here’s where I
find that the testimony is not going to be admitted.” The court explained that no expert
had interpreted, or demonstrated his or her qualifications to interpret, Lightfoot’s report
on Yepez’s MAOA genotype. The court noted the statement in Lightfoot’s report that
“the size of the deletion cannot be determined without further experimentation” and
found this to be significant, explaining that

       I don’t know how low—I didn’t hear any testimony educating me on—that
       this was a low MAOA, and I think what was missing was that you failed to
       call Dr. Lightfoot. . . . I can’t find that Dr. Walker’s testimony is going to be
       helpful to the trier of fact because I . . . don’t have any evidence before me
       from the person that did the testing that the result was a low MAOA.

3.     Motion for reconsideration

{11} Yepez filed a motion for reconsideration of the district court’s ruling excluding the
proffered expert testimony. He pointed out that the court had “seemingly determined
that the proposed testimony meets the requirements of Daubert and Alberico” yet also
that “the evidence would not be helpful to the trier of fact because . . . there was no
testimony from . . . Lightfoot that the test results indicated [Yepez] had a low functioning
MAOA gene.” Yepez argued that Rule 11-703 NMRA “allows an expert to base his
opinions on facts and data that he is aware of or has personally observed” and therefore
that the “separate admission of the laboratory results” is not required. Yepez attached
an affidavit from Raine, stating that Lightfoot’s report documenting a “rare” mutation on
the MAOA gene—namely, a deletion in the promoter region of that allele—“is consistent
with very low levels” of MAOA activity. An affidavit from Lightfoot confirmed this
interpretation. Yepez also submitted an affidavit from Walker, in which Walker stated
that he reviews reports like the one Lightfoot produced with some regularity and that the
report showed that Yepez has a low-activity MAOA genotype. Walker added that
“Yepez, due to his genetic characteristics and childhood maltreatment, is predisposed to
acts of impulsive violence and is substantially more likely to engage in acts of impulsive
violence than the ordinary person.”

{12} The district court denied Yepez’s motion. In its written order, the court impliedly
accepted the experts’ interpretations of Lightfoot’s report but found the proffered
testimony to be insufficiently reliable or relevant on the issue of whether Yepez formed
the specific intent to kill Ortiz. First, having explicitly identified Yepez’s recent filing of a
“notice of incapacity to form specific intent,” the court found that Yepez’s alleged
predisposition to violence did not meet the definition (provided in UJI 14-5101 NMRA) of
a mental disease or disorder which might render a person incapable of forming the
specific intent to kill. Second, as to whether Yepez’s alleged predisposition to violence
tended to show that, at the time of the murder, he did not have the specific intent to kill,
the district court concluded that Walker’s proffered opinion was not reliable or relevant.
Specifically, the consensus of the experts was that Yepez had low MAOA activity, but
not a complete deficiency of activity. And while the Brunner study found impulsive
violence to be a characteristic of a complete deficiency of MAOA activity, studies
regarding low MAOA activity combined with childhood maltreatment documented
increased outcomes of aggressive and antisocial behavior—not impulsive behavior or
impulsive violence as such. The district court determined that while the broad scientific
findings of the Caspi study and progeny met the Daubert factors, “Walker’s testimony
d[id] not meet the Daubert factors” and was “not grounded in established scientific
methods or principles” because it “misstate[s] . . . the results of the studies Dr. Walker
relies upon for his opinion.” (Emphasis added.)

B.     Trial and Sentencing

{13} After trial, the jury received instructions on conspiracy to commit murder; first-degree murder; the lesser included offenses of second-degree murder, voluntary
manslaughter, and involuntary manslaughter; tampering with the evidence; and unlawful
taking of a motor vehicle. The jury found Yepez guilty of (1) second-degree murder, (2)
tampering with evidence, and (3) unlawful taking of a motor vehicle. The district court
sentenced Yepez to twenty-two and one half years in prison.

C.     Opinion of the Court of Appeals

{14} Yepez appealed his conviction for second-degree murder, arguing that “the
district court improperly excluded expert opinion testimony related to his ability to form
deliberate intent and as a result, his conviction for second-degree murder should be
reversed and remanded for a new trial.” Yepez, 

, ¶ 1. Yepez also
argued that the proposed testimony would have constituted a defense to second-degree
murder, voluntary manslaughter, and involuntary manslaughter. Id. ¶ 35.

{15} In evaluating the admissibility of the expert testimony, the Court of Appeals did
not address the qualifications of the proffered experts because the State did not raise
the issue in the proceedings below. Yepez, 

, ¶ 24. The Court of
Appeals also assumed but did not decide that the underlying science supporting a
relationship between low MAOA activity accompanied by childhood maltreatment and
predisposition to antisocial and aggressive behavior was reliable. Id. ¶¶ 24, 31. It then
interpreted the district court’s basis for excluding the expert testimony as follows: “In
essence, the district court determined that there was an analytical gap between the
reliable scientific knowledge presented, including the Caspi study and the meta-study,
and . . . Walker’s affidavit testimony that [Yepez] is ‘predisposed to acts of impulsive
violence and is substantially more likely to engage in acts of impulsive violence than the
ordinary person.’” Id. ¶¶ 28-29 (concluding that the district court “believed that . . .
Walker’s testimony with respect to [Yepez’s] impulsivity went beyond the underlying
science” (emphasis added)).

{16} The Court of Appeals held that the district court’s exclusion of the testimony
based on an “analytical gap” was error and that the strength of the experts’ conclusions
based on the underlying MAOA science ought to have been left to the jury, relying on
this Court’s opinion in Acosta v. Shell Western Exploration & Production, Inc., 2016-
NMSC-012, ¶¶ 26-28, 370 P.3d. 761. Yepez, 

, ¶¶ 28-29. However, the
Court of Appeals also held that the error was harmless. Id. ¶¶ 32-36. It reasoned that
the expert testimony was only offered to “establish an impulsiveness” on Yepez’s part;
therefore, the testimony was pertinent to disproving that Yepez deliberated before killing
Ortiz but was not pertinent to any element of the lesser-included offenses—general
intent crimes for which no showing of deliberation was required. Id.
II.    DISCUSSION

{17} Both the State and Yepez seek this Court’s review of the Court of Appeals’
holdings. The State argues, consistent with the special concurrence of Judge Emil
Kiehne in the Court of Appeals, id. ¶¶ 38-41, that the Court of Appeals “improperly
reached out to decide that the district court abused its discretion,” given that any abuse
of discretion was harmless error. Therefore, the State urges, this Court ought to vacate
the portion of the Court of Appeals’ opinion dealing with the admissibility of the expert
testimony. Yepez, in turn, argues on cross-appeal that the district court indeed erred but
that the error was prejudicial and affected his constitutional rights. Yepez contends that
the proffered testimony was relevant not only to the first-degree murder charge but also
to the jury’s deliberation between second-degree murder and the lesser-included
charges of voluntary and involuntary manslaughter. For the reasons set forth below, we
hold that the district court did not abuse its discretion by excluding Yepez’s expert
testimony. For the same reasons, and because Yepez did not offer expert testimony on
any issue except the question of deliberate or specific intent to kill, we reject Yepez’s
cross-appeal.

A.     Standard of Review

{18} We review a district court’s admission or exclusion of evidence for an abuse of
discretion. State v. Downey, 

, 

, 

;
State v. Torres, 

, 

, 

. An abuse of
discretion occurs when the district court’s ruling “is clearly against the logic and effects
of the facts and circumstances of the case, is clearly untenable, or is not justified by
reason.” State v. Balderama, 

, 

, 

; see
also Alberico, 

, ¶ 63 (defining an abuse of discretion as a ruling that is
“obviously erroneous, arbitrary, or unwarranted”). Thus, while an appellate court should
not “rubber stamp[]” the district court’s admission of expert testimony, it should likewise
“be wary of substituting its judgment for that of the [district] court.” Alberico, 1993-
NMSC-047, ¶ 63 (explaining that the appellate court’s task is to conduct a “meaningful
analysis of the admission [of] scientific testimony to ensure that the [district] judge’s
decision was in accordance with the Rules of Evidence and the evidence in the case”).

B.     Admissibility of Expert Testimony on Yepez’s Alleged Predisposition to
       Impulsive Violence

{19} Admission of expert testimony in New Mexico is governed by Rule 11-702 and by
Rules 11-401 and 11-403 NMRA. Rule 11-702 provides that “if 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,” 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.” We have interpreted this rule to predicate the admissibility of expert
testimony “on the satisfaction of three requirements: (1) that the expert be qualified; (2)
that the testimony be of assistance to the trier of fact; and (3) that the expert’s testimony
be about scientific, technical, or other specialized knowledge with a reliable basis.”
Downey, 

 (citing Alberico, 

, ¶¶ 43-45). Rule 11-
401 also requires that expert testimony be relevant—that is, probative and “material to
the particular case.” Alberico, 

, ¶¶ 53, 55. However, if the prejudicial
effect of expert testimony substantially outweighs its probative value, Rule 11-403
allows a court to exclude such testimony. Id. ¶ 55. The district court’s role is to ensure
that the proffered expert evidence meets the foregoing requirements. See Parkhill v.
Alderman-Cave Milling & Grain Co. of N.M., 

, 

, 

 (holding that the district court must “ensure that an expert’s testimony rests on
. . . a reliable foundation and is relevant to the task at hand so that speculative and
unfounded opinions do not reach the jury”).

1.     Expert qualifications

{20} Because the State did not contest the qualifications of Yepez’s expert witnesses,
we assume without deciding that Walker and Raine are qualified by “knowledge, skill,
experience, training, or education” to testify about the relationship between certain
genotypes and behavioral traits, given the experts’ backgrounds in neuropsychology
and psychology and their knowledge in the area of behavioral genetics. See Downey,

. We therefore turn our attention to the remaining two,
interrelated requirements under Rule 11-702—that expert testimony assist the trier of
fact and have a reliable basis “in the knowledge and experience” of the expert’s
discipline. Alberico, 

, ¶ 45.

2.     Assistance to the trier of fact

{21} Whether expert evidence will assist the trier of fact is primarily a question of
relevance. Downey, 

 (citing Daubert, 

). Relevance
has two important aspects for our purposes. The first is reliability—also the heart of the
third requirement under Rule 11-702. See Alberico, 

, ¶ 53 (explaining
that only reliable evidence has probative value). The second is “fit” between the expert
evidence and the facts of the case. Downey, 

. These two
considerations together determine whether expert evidence is capable of “prov[ing]
what it purports to prove.” Id.; Alberico, 

, ¶ 53.

a.     Reliability of the scientific methodology

{22} Where an expert’s testimony is based on scientific knowledge, as in this case,
the proponent of the expert testimony must furnish “proof of [the] reliability of the
scientific technique or method upon which the expert testimony is premised.” Alberico,

, ¶ 53; see also Torres, 

 (“[I]t is error to admit
expert testimony involving scientific knowledge unless the party offering such testimony
first establishes the evidentiary reliability of the scientific knowledge.”). When
determining whether scientific evidence is reliable, the district court should consider the
Daubert factors, summarized by this Court in Torres:

       (1) whether a theory or technique can be (and has been) tested; (2)
       whether the theory or technique has been subjected to peer review and
       publication; (3) the known or potential rate of error in using a particular
        scientific technique and the existence and maintenance of standards
        controlling the technique’s operation; and (4) whether the theory or
        technique has been generally accepted in the particular scientific field.

 (brackets omitted) (internal quotation marks and citation
omitted). Additionally, the district court should “determine whether the scientific
technique is . . . capable of supporting opinions based upon reasonable probability
rather than conjecture.” Alberico, 

, ¶ 47.

{23} Here, the district court concluded that the scientific findings of low-activity MAOA
genotypes moderating the effects of childhood maltreatment to increase the likelihood of
antisocial and aggressive behavior in males satisfied the Daubert reliability factors. The
district court did not abuse its discretion in this regard, because both Raine and Walker
testified regarding the replication of studies supporting this relationship, the publication
of these studies in peer-reviewed journals, and the general acceptance of the findings in
the relevant scientific communities. The district court also recognized the Brunner
study’s finding that the rarer no-activity MAOA genotype was predictive of impulsive
aggressive behavior (i.e., Brunner syndrome). However, the district court concluded that
since Yepez has a low-activity MAOA genotype, not a no-activity MAOA genotype,
Walker’s testimony that Yepez is predisposed to impulsive violence was not based on
reliable scientific knowledge.

{24} The district court’s determination had a clear basis in the evidence before it. The
classic finding in the Caspi study was that low MAOA activity “moderates the impact of
early childhood maltreatment on the development of antisocial behavior in males,”
acknowledging that “[a]ntisocial behavior is a complicated phenotype.” 5 Caspi, supra, at
852-53. The various indicators of antisocial behavior in the Caspi study were not
exclusive to impulsive violence; they included adolescent conduct disorder, convictions
for violent crimes, personality disposition toward violence, and antisocial personality
disorder. Id. at 852. Likewise, neither the 2014 Byrd and Manuck meta-analysis nor an
earlier meta-analysis referenced by the experts, J. Kim-Cohen et al., MAOA,
Maltreatment, and Gene-Environment Interaction Predicting Children’s Mental Health:
New Evidence and a Meta-Analysis, 11 Molecular Psychiatry 903, 903-13 (2006), 6
identified increased outcomes of impulsive violence in males with low MAOA activity
and a history of childhood maltreatment. Instead, these studies identified outcomes of
antisocial behavior, generally. Id. at 910-11; Byrd and Manuck, supra, at 14-15 (noting
that the “moderately reliable interaction” of low MAOA activity and childhood
maltreatment “predict[ed] outcomes . . . of . . . both violent and non-violent antisocial
behaviors,” suggesting that “the low-activity MAOA genotype heightens maltreatment-


5“Phenotype” is “an individual’s observable traits, such as height, eye color, and blood type. The genetic
contribution to the phenotype is called the genotype.” See Nat’l Insts. of Health, Nat’l Human Genome
Research Inst., Talking Glossary of Genetic Terms: Phenotype, available at
https://www.genome.gov/genetics-glossary/Phenotype (last visited Nov. 25, 2020).
6Available at https://www.researchgate.net/publication/6982612_MAOA_Maltreatment_and_Gene-Environment_Interaction_Predicting_Children’s_Mental_Health_New_
Evidence_and_a_Meta-Analysis/link/5402fd010cf2c48563afc517/download (last visited Nov. 30, 2020).
dependent risk for a range of conduct problems and not aggression or criminal violence
specifically”).

{25} While some studies speculate that MAOA may be involved in regulating impulse
control, others hypothesize that impulse control is a separate variable dependent largely
on frontal lobe brain function. Compare Byrd and Manuck, supra, at 15 (“It is possible
that [childhood] maltreatment . . . engenders antagonistic and antisocial motivations that
are abetted by MAOA-modulated impairments in inhibitory control.”), with C.J.
Ferguson, An Evolutionary Approach to Understanding Violent Antisocial Behavior:
Diagnostic Implications for a Dual-Process Etiology, 8 Journal of Forensic Psychology
Practice 321, 322-25, 335-36 (2008) (hypothesizing that the genetically-influenced
development of an antisocial personality and a deficiency in impulse control due to, for
example, frontal lobe brain injuries are separate variables influencing the ultimate
outcome of violent behavior). 7 These differences illustrate that it is not yet understood
how MAOA activity and childhood maltreatment increase the likelihood of antisocial
behavior. See, e.g., Kim-Cohen, supra, at 911 (“[A] statistical interaction between a
genotype and an environmental risk factor requires further research to uncover the
biological mechanisms involved in the interaction . . . [and] represents an important
launching pad for developmental neuroscience research into the underlying causal
mechanisms involved in the etiology of psychopathology.”).

{26} Indeed, Walker testified that the mechanism by which a low-activity MAOA
genotype increases the risk for violence is unknown and that there are “lots of different
theories,” some of which suggest the involvement of impulse-control functions and
some of which do not. Although Walker answered leading questions regarding
“impulsive violence” and characterized Yepez’s murder of Ortiz as “an act of impulsive,
senseless violence,” he expressed his own opinion during his testimony without
reference to impulsivity. More importantly, Walker did not explain or even assert in his
testimony or subsequent affidavit that the relevant body of research establishes a link
between low MAOA activity and impulsive violence. Similarly, Raine testified that the
combination of low MAOA activity and childhood maltreatment “is associated with
antisocial aggressive behavior, and a number of people think it’s especially with respect
to impulsive aggressive behavior.” He later stated that low MAOA activity and childhood
maltreatment “contribute to, for example, impulse control” and doing things without
planning, and “can affect cognition, also emotion.” But Raine did not explain the
foregoing opinions, or how he arrived at them, and the referenced studies furnish no
explanation.

{27} Accordingly, the district court was within its discretion to exclude as lacking in
scientific reliability an opinion that Yepez is predisposed to impulsive violent behavior.
The Court of Appeals held otherwise through a misinterpretation of our holding in
Acosta, 

. Yepez, 

, ¶¶ 28-29.




7Available for purchase at https://www.tandfonline.com/doi/full/10.1080/
15228930802199168 (last visited Nov. 25, 2020).
{28} In Acosta, a toxic tort case, the plaintiffs offered the expert testimony of Dr.
James Dahlgren, who was of the opinion that the plaintiffs’ exposures to certain toxic
chemicals produced by the defendants had caused the plaintiffs’ autoimmune diseases.

, ¶¶ 1, 6. Dahlgren’s opinion was based on a number of animal and
human studies, including a study conducted by Dahlgren himself on the plaintiffs, all of
which linked the toxic agents to autoimmune diseases in humans. Id. ¶¶ 6-16. The
district court excluded the testimony for lack of relevance to the issue of general
causation—that is, whether the toxic agents were capable of causing autoimmune
diseases in humans. Id. ¶ 29. Citing the United States Supreme Court’s opinion in
General Electric Co. v. Joiner, 

 (1997), the district court explained that
there was too great an “analytical gap” between the underlying data and the inference
drawn on causation. Acosta, 

, ¶ 26. Specifically, the district court found
that the study conducted by Dahlgren had failed “to bridge the gap from association to
causation,” and that Dahlgren’s extrapolation from the animal studies was insufficient to
establish causation in humans. Id. ¶¶ 18, 39 (internal quotation marks omitted). The
plaintiffs appealed the district court’s grant of summary judgment based in part on the
exclusion of Dahlgren’s opinion, and the Court of Appeals affirmed the district court. Id.
¶¶ 18-19.

{29} This Court reversed, holding that Dahlgren’s testimony should have been
admitted. Id. ¶ 2. We observed that New Mexico has never adopted the Joiner rule that
a judge may reject expert testimony where the “analytical gap” between the underlying
evidence and the expert’s conclusions is too great. Acosta, 

, ¶ 27.
Indeed, we concluded that a rule is “inconsistent with longstanding New Mexico law that
leaves credibility determinations and weighing of the evidence to the trier of fact.” Id. ¶
28 (citation omitted). We held that, in the context of first-exposure toxic tort cases,
where scientific analysis on a particular causal relationship may not be fully developed,
expert testimony on general causation may nevertheless be reliable and admissible
when it is based on appropriate methodology. Id. ¶¶ 30-34. We noted that Dahlgren had
given an explanation, utilizing such widely accepted scientific guidelines for the
interpretation of epidemiological studies, as to why the association found in his study
was causal. Id. ¶¶ 32-35, 40-42. He also offered a scientific basis for his extrapolation
from the various animal studies to humans, accounting for the differing dose response
relationship as between mice and humans. Id. ¶¶ 37-38. We therefore concluded that
Dahlgren’s methodology supported a valid scientific inference that was probative of
causation, and that the district court had “improperly blurred the line between [its]
province to evaluate the reliability of Dahlgren’s methodology and the jury’s province to
weigh the strength of Dahlgren’s conclusions.” Id. ¶ 41.

{30} In contrast to Dahlgren, who explained the methodology behind his interpretation
of his own study and his extrapolation from animal studies, see id. ¶ 42, neither Walker
nor Raine set forth the steps they took, methodologically speaking, from the research to
their conclusions. Specifically, neither Walker nor Raine explained how they arrived at
an opinion that low MAOA activity and childhood maltreatment predispose males to
impulsive violence when the studies upon which they relied documented increased
outcomes of antisocial aggressive behavior without reference to impulsivity.
Accordingly, their opinions were properly excluded not because they made a novel
extrapolation across an analytical gap but because of the absence of scientific
methodology in support of the specific conclusion reached.

b.    Whether the scientific methodology was properly applied to the facts

i.    Fit between Brunner syndrome and Yepez’s genotype

{31} Another way of understanding the district court’s order is that it found a lack of
“fit” between the proffered expert testimony and the facts of the case. Specifically, the
court found no fit between the experts’ apparent reliance on the findings of the Brunner
study and Yepez’s genotype.

{32} To explore this issue, we first consider whether the findings of the Brunner study
would be “directly related” to the theory of Yepez’s case. See Balderama, 2004-NMSC-
008, ¶ 24. Here, Yepez was charged with first-degree murder, a crime requiring the
State to prove that Yepez had the specific or deliberate intent to kill the victim. See
NMSA 1978, § 30-2-1(A)(1) (1994) (defining first-degree murder as “any kind of willful,
deliberate and premeditated killing”). The deliberate intent to kill another person is
defined in UJI 14-201 NMRA, in part, as follows:

      The word deliberate means arrived at or determined upon as a result of
      careful thought and the weighing of the consideration for and against the
      proposed course of action. A calculated judgment and decision may be
      arrived at in a short period of time. A mere unconsidered and rash
      impulse, even though it includes an intent to kill, is not a deliberate
      intention to kill. To constitute a deliberate killing, the slayer must weigh
      and consider the question of killing and his reasons for and against such a
      choice.

One defense to a first-degree murder charge is that, due to a mental disease or
disorder, the defendant was incapable of forming the deliberate intent to kill. See UJI
14-5110 NMRA; State v. Boyett, 

, 

, 

(holding that expert testimony would have been required to show that the defendant’s
alleged “organic brain damage caused his inability to form specific intent”). An
alternative approach is for the defendant to submit evidence with a tendency “to make
the existence of deliberation . . . less probable,” or in other words, evidence tending to
negate the element of deliberate intent. Balderama, 

 (holding
that expert testimony that the defendant had neurological deficits and multiple
psychiatric diagnoses resulting in difficulty planning or controlling angry impulses was
evidence “tending, to some degree, to refute the element of deliberation necessary for
first-degree murder”).

{33} The purpose of the expert testimony tendered by Yepez clearly focused on
whether Yepez formed the specific or deliberate intent to kill Ortiz. However, it is
somewhat unclear whether the purpose was to show an incapacity to form such intent
due to a mental disease or disorder or to show a low probability that Yepez did, in fact,
form the specific intent to kill Ortiz. Despite Yepez’s arguments to the contrary, we
conclude that both Yepez’s arguments in motion practice and the experts’ opinions
themselves point to the latter purpose. The Court of Appeals reached the same
conclusion. Yepez, 

, ¶¶ 30-31. Even if Yepez advanced both theories,
there was no evidence that Yepez’s alleged predisposition was a mental disease or
disorder or that any disease or disorder rendered him incapable of deliberating and
planning—and indeed, the testimony was to the contrary. For instance, Walker testified
that Yepez has some capacity to act intentionally and to consider the consequences of
his actions. Walker also testified that he can make no “clear connection” between
Yepez’s genetic predisposition and what happened on the night of Ortiz’s death since a
predisposition does “[n]ot directly” cause a person to behave in a certain way. Thus, we
consider only whether the proffered expert testimony tended to negate the element of
deliberate intent.

{34} The finding of the Brunner study was that those with a no-activity MAOA
genotype are impulsively aggressive. Brunner study, supra, at 578-79. If Yepez had this
characteristic of impulsive aggression, it would tend to negate the element of deliberate
intent. But for the findings of the Brunner study to be applicable, the record would have
to show that Yepez in fact has the rare no-activity MAOA genotype. Downey, 2008-
NMSC-061, ¶ 34 (holding that scientific knowledge must be properly applied and that,
while an expert may base his or her opinion on factual assumptions, those assumptions
“must find evidentiary foundation in the record”). The record contains no such evidence;
further tests would have been required to ascertain this information. Nevertheless,
Walker and Raine seemingly imported the findings scientifically attributable to Brunner
syndrome and concluded, on the basis of Yepez’s low-activity MAOA genotype, that
Yepez was predisposed to impulsive aggression. We agree with the district court that
this apparently unfounded reliance on the Brunner study renders the proffered expert
opinions merely speculative and therefore irrelevant. See Downey, 

 (“Expert testimony may be received if, and only if, the expert possesses such facts
as would enable him to express a reasonably accurate conclusion as distinguished from
mere conjecture.” (internal quotation marks and citation omitted)); see also
Christopherson v. St. Vincent Hosp., 

, 

 (holding
that, if a scientific technique requires certain data in order to render the expert’s opinion
relevant, “the district court acts within its discretion to exclude testimony not based on
such data”).

ii.    Fit between low-activity MAOA genotype and Yepez’s behavior

{35} We are also persuaded by the district court’s broader finding, set forth in its initial
order following the Daubert/Alberico hearing, regarding a lack of fit between the science
and the facts of Yepez’s case. The district court observed that there still was “work to be
done” in the field of MAOA research, taking up the State’s contention that the alleged
predisposition to violence resulting from a low-activity MAOA genotype and childhood
maltreatment is not yet understood with sufficient precision to be reliable or relevant as
a predictor of violence in individuals. Assuming for the sake of argument that a
predisposition to antisocial aggressive behavior in maltreated children with low MAOA
activity includes at least some statistically significant predisposition to impulsive violent
behavior, is such scientific knowledge, as presented in this case, relevant to whether
Yepez formed the specific intent to kill Ortiz? We think not, and we explain why.

{36} The Caspi study notes that the environmental factor of childhood maltreatment
alone increases an individual’s risk of criminality in adulthood by fifty percent. Caspi
study, supra, at 851. Raine and Walker testified that other environmental risk factors for
antisocial aggressive behavior include poor parenting, poor nutrition, presence of drug
or alcohol abuse in the home, and bad neighborhoods. Raine and Walker also testified
to the “wide array of biological risk factors that can be associated with increased
violence” such as “poor functioning in the frontal region of the brain,” low resting heart
rate, (high) testosterone levels, low IQ, antisocial personality, and psychopathic
personality. Raine could not say what percentage of those with a low-MAOA genotype
in fact go on to commit violent behavior. Although Walker testified that low MAOA
activity plus childhood maltreatment increases the risk of committing a violent act to
85% (the source of that figure is unclear), he acknowledged that “we don’t know in any
given individual exactly how factors interact to produce a certain set of behavior” and
that there was no “clear connection” between Yepez’s MAOA variant and what
happened when Yepez killed Ortiz.

{37} Ambiguity surrounding the significance of the MAOA genotype to a complex and
multivariable behavioral phenotype is acknowledged in the 2006 meta-analysis by Kim-Cohen et al., which noted that the statistical interaction between low MAOA and
childhood maltreatment is “likely to be one of myriad factors involved in the
development of biological sensitivity to stress and . . . social context.” Kim-Cohen,
supra, at 911. Likewise, a 2011 meta-analysis concluded that, although many studies
had produced statistically significant results consistent with those of the Caspi study, the
observed interactions between low-activity MAOA and childhood maltreatment

       tended to be limited in magnitude, accounting for only a small portion of
       the variance in the models. The small magnitude of the interaction effects
       suggests that the contribution of these interactions to antisocial [behavior],
       over and above the main effect of maltreatment exposure, may be
       somewhat limited in scope.

D.M. Fergussen et al., MAOA, Abuse Exposure and Antisocial [Behavior]: 30-Year
Longitudinal Study, 198 The British Journal of Psychiatry 457, 462-63 (2011) (also
observing that further research is required “to validate the role of MAOA genotype in
antisocial behavior” since at least one study found no link between MAOA genotypes
and MAO levels in the brain). 8

{38} These uncertainties and the introduction of so-called genetic susceptibility
testimony (regarding MAOA and other genes linked to increased risk of aggression) in
the sentencing phase of a murder case in Italy caused a group of clinical geneticists,

8Available at https://www.cambridge.org/core/services/aop-cambridgecore/content/view/B32E1FFD94CA5CB43EFFE9039536D4BB/S0007125000255438a.pdf/maoa_abuse_
exposure_and_antisocial_behaviour_30year_longitudinal_study.pdf (last visited December 22, 2020).
bioethicists, and others to express concern that “[g]iven the state of the art in genetics,
the possibility of using genetic variants to evaluate the actual mental capacity of a
person at a given time is far from being established.” Francesca Forzano et al., Italian
Appeal Court: A Genetic Predisposition to Commit Murder?, 18 European Journal of
Human Genetics, 519, 519 (2010). 9 This article, cited by the State in motion practice
before the district court, questions the use of such “susceptibility testing” in legal
proceedings, noting that

        [t]he vast majority of these tests, if not all, are still purely research-based
        and have not received any formal evaluation in terms of clinical validity
        and utility. In our opinion, no susceptibility test should as yet be used in
        forensic or . . . judicial settings. The use of genetic tests in forensic
        contexts should be restricted to tests with proven clinical utility for the
        diagnosis of a disease relevant to the case judged.

Id. at 519-20. The State also cited psychology literature indicating that genetic tests for
genotypes “predictive of antisocial behavior and violence are not yet widely employed”
because they have not yet been shown to meet validity requirements applicable to
forensic psychological tests. See C.J. Ferguson, supra, at 335. A validity coefficient (an
index that “reflects how well an assessment instrument predicts a well-accepted
indicator of a given . . . criterion”) 10 of 0.4 or greater is generally required for
psychological tests. See C. J. Ferguson, supra, at 336.

{39} This issue raises a still broader point. The question, it seems to us, is whether a
person has the phenotype, or trait, of impulsive antisocial behavior, not whether that
person is at risk for developing the phenotype. We acknowledge the probabilistic nature
of proof tending to negate the element of deliberate intent; in Balderama, we expressed
the relevance of testimony about the defendant’s mental condition as tending “to some
degree, to refute the element of deliberation necessary for first-degree murder.” 2004-
NMSC-008, ¶ 27. But there, the defendant’s likelihood of having deliberated or planned
the killing could be weighed based on an objective diagnosis of “neurological deficits,”
“impulse-control disorder, polysubstance abuse, and antisocial personality disorder” and
the known effects of these conditions. Id. Here, Walker diagnosed Yepez with
depression and addiction but offered no testimony that the symptoms of these
conditions include increased impulsive aggression. Walker also testified that Yepez has
an IQ within the low-average range and that he performed well on tests designed to rule
out brain injury and measure higher order reasoning and problem-solving. He did not
testify that Yepez had any neural deficits or other symptoms or signs consistent with
impulsivity or impulsive aggression. Walker apparently identified the killing of Ortiz as
the evidence that Yepez had the relevant impulsive antisocial phenotype. The problems
with such a circular opinion are obvious. As the scientists in the Forzano article stated,

9Available at
https://www.researchgate.net/publication/41849562_Italian_appeal_court_A_genetic_predisposition_to_c
ommit_murder (last visited Nov. 25, 2020).
10American Psychological Association, Dictionary of Psychology, validity coefficient (2020), available at
https://dictionary.apa.org/validity-coefficient (last visited Nov. 25, 2020).
“[a] person should be judged on the basis of his actual condition and mental capacity at
the moment of the act, independent of any theoretical predisposition to develop some
disease or inappropriate [behavior].” Forzano, supra, at 520. We are also wary of the
risks of stigmatization associated with simplistic interpretations of the “causal relations
between genetic variants associated with violence or aggression and actual violent or
aggressive [behavior].” Id. (warning that overemphasis on genetic susceptibility might
inappropriately justify labeling an individual as more prone to recurrent crime).

{40} We hold that evidence of mere genetic susceptibility to a given mental condition
is not relevant on the issue of deliberate intent, at least in the absence of evidence that
such susceptibility is so well understood and has such strong predictive value as to be
clinically validated as an indicator of the mental condition.

C.     Yepez’s Cross-Appeal Alleging Prejudicial and Constitutional Error

{41} Yepez contends that the district court erred in excluding the proffered testimony
because it was relevant not only to the first-degree murder charge but also to the jury’s
consideration of whether to convict Yepez for second-degree murder, voluntary
manslaughter, or involuntary manslaughter. We agree with the Court of Appeals that
Yepez offered expert testimony only on the issue of whether Yepez deliberated before
killing Ortiz. Yepez, 

, ¶¶ 35-36. The issue of deliberation was irrelevant
to the lesser included offenses—general intent crimes requiring no proof of deliberation.

 To the extent Yepez now claims that the expert testimony was relevant on an issue
other than deliberate intent, that claim was not presented to the district court and was
therefore not preserved for appeal. State v. Lopez, 

, 

, 

. This Court reviews an unpreserved claim on appeal only for
fundamental or jurisdictional error. “The doctrine of fundamental error applies only under
exceptional circumstances and only to prevent a miscarriage of justice.” State v. Barber,

, 

, 

. This Court need only correct errors
that “shock the conscience,” a phrase used regarding “cases with defendants who are
indisputably innocent, and cases in which a mistake in the process makes a conviction
fundamentally unfair notwithstanding the apparent guilt of the accused.” Id. ¶ 17
(internal quotation marks and citation omitted). Given our holding that the district court
did not abuse its discretion in finding the proffered expert testimony unreliable and
inadmissible, the exclusion of the testimony did not render Yepez’s conviction for
second-degree murder fundamentally unfair. We therefore deny Yepez’s request for a
new trial.

III.   CONCLUSION

{42} For the reasons set forth hereinabove, we reverse the Court of Appeals’
determination on the admissibility of Yepez’s proffered expert testimony, reject Yepez’s
cross-appeal requesting a new trial, and affirm Yepez’s conviction for second-degree
murder.

{43}   IT IS SO ORDERED.
JUDITH K. NAKAMURA, Justice,
Retired, Sitting by Designation

WE CONCUR:

MICHAEL E. VIGIL, Chief Justice

BARBARA J. VIGIL, Justice

C. SHANNON BACON, Justice

DAVID K. THOMSON, Justice