Opinion ID: 2377543
Heading Depth: 1
Heading Rank: 6

Heading: Definition of mental retardation

Text: Although the United States Supreme Court has held that the execution of mentally retarded individuals violates the Eighth Amendment's prohibition against cruel and unusual punishment, Atkins, 536 U.S. at 321, 122 S.Ct. 2242, the Court did not prescribe a definition of mental retardation or procedures for determining when an individual is mentally retarded. Instead, the Court left  `to the State[s] the task of developing appropriate ways to enforce [this] constitutional restriction upon ... execution[s],'  id. at 317, 122 S.Ct. 2242 (first, third, and fourth alterations in original) (quoting Ford v. Wainwright, 477 U.S. 399, 416-17, 106 S.Ct. 2595, 91 L.Ed.2d 335 (1986)). The Nevada Legislature accomplished that task with the passage of NRS 174.098, which sets forth the procedure for raising mental retardation in a capital case and defines mentally retarded. The statute provides that upon motion by a defendant, [3] the district court must conduct an evidentiary hearing to determine whether the defendant is mentally retarded. NRS 174.098(1), (2); see also NRS 175.554(5). The defendant bears the burden of proving by a preponderance of the evidence that he is mentally retarded, NRS 174.098(5)(b), which the Legislature defines as significant subaverage general intellectual functioning which exists concurrently with deficits in adaptive behavior and manifested during the developmental period, NRS 174.098(7). This court has not yet had occasion to address the statutory definition of mentally retarded. We take this opportunity to do so. The definition of mentally retarded in NRS 174.098(7) was taken from NRS 433.174, which was adopted in 1975 and defines mental retardation for purposes of NRS Title 39 (Mental Health). See Hearing on A.B. 15 Before the Assembly Comm. on Judiciary, 72d Leg. (Nev., Feb. 25, 2003). The statutory definition conforms to the clinical definitions espoused by two professional associations that are concerned with mental retardationthe American Association on Mental Retardation (AAMR) [4] and the American Psychiatric Association (APA). [5] In particular, the statutory definition and the two clinical definitions share three concepts: (1) significant limitations in intellectual functioning, (2) significant limitations in adaptive functioning, and (3) age of onset. [6] Given the similarities between the statutory definition and the clinical definitions of mental retardation, the AAMR and APA provide useful guidance in applying the definition set forth in NRS 174.098. The first conceptsignificant limitations in intellectual functioninghas been measured in large part by intelligence (IQ) tests. Because there is a measurement error of approximately 5 points in assessing IQ, which may vary depending on the particular intelligence test given, Diagnostic and Statistical Manual of Mental Disorders 41 (4th ed. 2000), the clinical definitions indicate that individuals with IQs between 70 and 75 fall into the category of subaverage intellectual functioning, id. at 42. See also State v. McManus, 868 N.E.2d 778, 785 (Ind.2007); State v. Vela, 279 Neb. 94, 777 N.W.2d 266, 294 (2010); Ex Parte Briseno, 135 S.W.3d 1, 7 n. 24 (Tex.Crim.App.2004). Although the focus with this element of the definition often is on IQ scores, that is not to say that objective IQ testing is required to prove mental retardation. Other evidence may be used to demonstrate subaverage intellectual functioning, such as school and other records. See McManus, 868 N.E.2d at 787; Com. v. Vandivner, 599 Pa. 617, 962 A.2d 1170, 1187 (2009); see also Morris v. State, ___ So.3d ___, ___ (Ala.Crim.App.2010) (considering school records in determining whether defendant was mentally retarded), petition for cert, filed, 79 U.S.L.W. 3377 (U.S. Dec. 16, 2010) (No. 10-808). But the burden remains on the defendant to present evidence affirmatively establishing this element of mental retardation. See NRS 174.098(5)(b). To be found mentally retarded, an individual with subaverage intellectual functioning must also meet the second element, showing significant deficits in adaptive behavior. As the APA explains, individuals  `with IQs somewhat lower than 70'  would not be diagnosed as mentally retarded if there  `are no significant deficits or impairment in adaptive functioning.' Stripling v. State, 261 Ga. 1, 401 S.E.2d 500, 504 (1991) (quoting Diagnostic and Statistical Manual of Mental Disorders 37 (3d ed. 1980)); Myers v. State, 130 P.3d 262, 268 (Okla.Crim.App. 2005) (stating that IQ tests are not solely determinative of mental retardation issue). Thus, the interplay between intellectual functioning and adaptive behavior is critical to a mental retardation diagnosis. Adaptive behavior has been defined as the collection of conceptual, social, and practical skills that have been learned by people in order to function in their everyday lives, and thus, limitations on adaptive behavior are reflected by difficulties adjusting to ordinary demands made in daily life. Com. v. Miller, 585 Pa. 144, 888 A.2d 624, 630 (2005); see also In re Hawthorne, 35 Cal.4th 40, 24 Cal.Rptr.3d 189, 105 P.3d 552, 557 (2005); McManus, 868 N.E.2d at 787 (noting that Indiana's adaptive behavior prong most closely resembles the AAMR definition); Vela, 777 N.W.2d at 294; Briseno, 135 S.W.3d. at 7 n. 25; Diagnostic and Statistical Manual of Mental Disorders 42 (4th ed. 2000) (explaining that [a]daptive functioning refers to how effectively individuals cope with common life demands and how well they meet the standards of personal independence expected of someone in their particular age group, sociocultural background, and community setting). The final element in finding mental retardation is the age of onset. NRS 174.098(7) refers to onset during the developmental period. We must therefore delineate the boundaries of the developmental period referenced in the statute. To do so, we look to the purpose of the age-of-onset requirement, the clinical definitions of mental retardation, and other jurisdictions' definitions of mental retardation. The purpose behind the age-of-onset requirement is twofold. The requirement ensures that the mental retardation developed during the developmental period, as opposed to forms of brain damage that occur later in life, and, in the criminal arena, it precludes defendants from feigning mental retardation once charged with a capital crime. Alexis Krulish Dowling, Comment, Post-Atkins Problems With Enforcing the Supreme Court's Ban on Executing the Mentally Retarded, 33 Seton Hall L.Rev. 773, 805 (2003); see Penny J. White, Treated Differently in Life but Not in Death: The Execution of the Intellectually Disabled After Atkins v. Virginia, 76 Tenn. L.Rev. 685, 707 (2009) (stating that [t]he purpose of this [age] onset requirement is not to exclude some people with intellectual disabilities from the mental retardation category, but rather to differentiate between individuals with mental retardation and individuals with other mental deficits caused by injuries or diseases that occurred during adulthood); Nita A. Farahany, Cruel And Unequal Punishments, 86 Wash. U.L.Rev. 859, 884 (2009) (noting that [i]n medicine, age of onset helps a clinician to distinguish mental retardation from other mental disabilities). The clinical definitions adopted by the AAMR and the APA focus on the age of 18 years, requiring that subaverage intellectual functioning and adaptive behavior deficits manifest themselves before that age. Most jurisdictions are in step with the AAMR and APA and have required, either by statute or caselaw that these intellectual and adaptive deficits must originate before 18 years of age. [7] E.g., Ariz.Rev.Stat. Ann. § 13-753(K)(3) (2010); Ark.Code Ann. § 5-4-618(a)(l)(A) (2006); Cal.Penal Code § 1376(a) (West Supp.2011); Conn. Gen.Stat. Ann. § 53a-46a(h) (2009); Conn. Gen. Stat. § 1-lg (2009) (defining mental retardation); Del.Code Ann. tit. 11, §§ 4209(d)(3)(a), 4209(d)(3)(d)(2) (2007); Fla. Stat. Ann. § 921.137(1) (West 2006 & Supp. 2011); Idaho Code Ann. § 19-2515A(l)(a) (2004 & Supp.2010); 725 Ill. Comp. Stat. Ann. 5/114-15(d) (West 2006); La.Code Crim. Proc. Ann. art. 905.5.1(H)(1) (2008 & Supp.2011); Kan. Stat. Ann. § 21-4623(e) (Supp.2010); Kan. Stat. Ann. § 76-12b01(d) (1997); N.C. Gen. Stat. § 15A-2005(a)(l)(a) (2009); Okla. Stat. Ann. tit. 21, § 701.10b(B) (West 2002 & Supp.2010); S.D. Codified Laws § 23A-27A-26.1 (2004); Tenn.Code Ann. § 39-13-203(a)(3) (2010); Va.Code Ann. § 19.2-264.3:1.1(A) (2008 & Supp.2010); Wash. Rev. Code. Ann. § 10.95.030(2)(e) (West 2002 & Supp.2011); In re Brown, 457 F.3d 392, 396 (5th Cir.2006) (recognizing that Texas courts have adopted the AAMR definition of mental retardation providing that mental retardation must manifest before age of 18 years); Chase v. State, 873 So.2d 1013, 1027-28 (Miss.2004) (adopting AAMR and APA definition of mental retardation, including onset before age of 18 years); Com. v. Miller, 585 Pa. 144, 888 A.2d 624, 629-31, 630 n. 7 (2005) (same). A few jurisdictions, like Nevada, have statutes that refer more generally to the developmental period. Ala.Code § 15-24-2(3) (LexisNexis 1995 & Supp. 2010); Colo.Rev. Stat. § 18-1.3-1101(2) (2010); Ga.Code Ann. § 17-7-131(a)(3) (2008 & Supp.2010); Ky. Rev.Stat. Ann. § 532.130(2) (LexisNexis 2008); S.C.Code Ann. § 16-3-20(C)(b)(10) (2003). Courts in two of those states have answered the same question that we face in this casewhat is the developmental period? Those courts have defined development period as the time before an individual reaches 18 years of age, consistent with the age of onset used in the clinical definitions and in a majority of jurisdictions. Holladay v. Campbell, 463 F.Supp.2d 1324, 1341-42 (N.D.Ala.2006); Ex Parte Perkins, 851 So.2d 453, 456 (Ala.2002); Stripling v. State, 261 Ga. 1, 401 S.E.2d 500, 504 (1991) (observing that Georgia's statutory definition of mental retardation is consistent with APA, which identifies developmental period as before age 18). We conclude that the approach to the age-of-onset requirement taken by the AAMR and APA and the majority of jurisdictions that a person suffered from mental retardation prior to the age of 18 yearsbest serves the purpose behind the requirement. Focusing on the period before a person reaches 18 years of age ensures that the person suffers from mental retardation rather than some other mental impairment that occurred later in life and that a criminal defendant cannot feign mental retardation to avoid a capital sentence. Considering the purpose behind the age-of-onset requirement, the guidance provided by the AAMR and APA, and the consensus among most jurisdictions, we conclude that the developmental period referenced in NRS 174.098(7) is the period before a person reaches 18 years of age. Accordingly, subaverage intellectual functioning and adaptive behavior deficits must originate before 18 years of age to meet the definition of mental retardation contemplated by NRS 174.098. [8] With this understanding of the elements of mental retardation in mind, we turn to the district court's decision and Ybarra's challenges to it. To begin with, we must address the standard of review that applies when a district court's decision regarding a claim of mental retardation is reviewed on appeal. While some courts have reviewed such decisions for an abuse of discretion, see Rondon v. State, 711 N.E.2d 506 (Ind.1999); State v. White, 118 Ohio St.3d 12, 885 N.E.2d 905 (2008), or clear error, see Com. v. Crawley, 592 Pa. 222, 924 A.2d 612, 616 (2007) ([O]ur standard of review [for mental retardation determinations] is whether the factual findings are supported by substantial evidence and whether the legal conclusion drawn therefrom is clearly erroneous.), others have treated it as a mixed question of fact and law, see Walker v. Kelly, 593 F.3d 319, 322-23 (4th Cir.) (applying Virginia law to mental retardation determinations, appellate courts review district court's factual findings for clear error and legal conclusions de novo), cert. denied, 560 U.S. ___, 130 S.Ct. 3318, 176 L.Ed.2d 1215 (2010); Cherry v. State, 959 So.2d 702, 712 (Fla.2007) (noting that in reviewing mental health determinations, appellate courts employ[ ] the standard of whether competent, substantial evidence supported the [postconviction] court's determination and questions of law are reviewed de novo). In our view, the determination whether a capital defendant is mentally retarded is based on factual conclusions but requires distinctively legal analysis to determine whether the elements of mental retardation have been proven, and therefore, we will review such a determination as a mixed question of fact and law. See Hernandez v. State, 124 Nev. 60, ___, 188 P.3d 1126, 1131 (2008) (We have noted that review of a district court's decision as a mixed question of law and fact is appropriate where the determination, although based on factual conclusions, requires distinctively legal analysis.). Accordingly, we will give deference to the district court's factual findings so long as those findings are supported by substantial evidence and are not clearly erroneous, but we will review the legal consequences of those factual findings de novo. See Lader v. Warden, 121 Nev. 682, 686, 120 P.3d 1164, 1166 (2005) (applying mixed-question standard of review). Matters of credibility in this area remain, however, within the district court's discretion. See Mann v. State, 118 Nev. 351, 356, 46 P.3d 1228, 1231 (2002) (observing that on remand for evidentiary hearing the district court will be better able to judge credibility). See generally Mulder v. State, 116 Nev. 1, 15, 992 P.2d 845, 853 (2000) (The trier of fact determines the weight and credibility to give conflicting testimony.). For the reasons explained below, we conclude that Ybarra failed to show that the onset of any subaverage general intellectual functioning and adaptive behavior deficits occurred before he reached age 18. Accordingly, the district court did not err by denying the motion to strike the death penalty on this ground.