State v. Yepez

2021 NMSC 010, 483 P.3d 576
CourtNew Mexico Supreme Court
DecidedFebruary 25, 2021
StatusPublished
Cited by11 cases

This text of 2021 NMSC 010 (State v. Yepez) is published on Counsel Stack Legal Research, covering New Mexico Supreme Court primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
State v. Yepez, 2021 NMSC 010, 483 P.3d 576 (N.M. 2021).

Opinion

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: 2021-NMSC-010

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, 428 P.3d 301. 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., 509 U.S. 579 (1993), and State v. Alberico, 1993-NMSC-047, 116 N.M. 156, 861 P.2d 192. 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

Free access — add to your briefcase to read the full text and ask questions with AI

Related

State v. Armstrong
New Mexico Court of Appeals, 2025
State v. Soto
New Mexico Supreme Court, 2025
State v. Cano-Sammis
New Mexico Court of Appeals, 2024
Hernandez v. Reuter
New Mexico Court of Appeals, 2022
Collado v. Fiesta Park Healthcare, LLC
New Mexico Court of Appeals, 2022
Collado v. Fiesta Park Healthcare
New Mexico Court of Appeals, 2022

Cite This Page — Counsel Stack

Bluebook (online)
2021 NMSC 010, 483 P.3d 576, Counsel Stack Legal Research, https://law.counselstack.com/opinion/state-v-yepez-nm-2021.