Opinion ID: 891607
Heading Depth: 3
Heading Rank: 1

Heading: Defendant Has Mental Retardation Under New Mexico Law

Text: {10} Mental retardation is defined by Section 31-9-1.6(E) as significantly subaverage general intellectual functioning existing concurrently with deficits in adaptive behavior. Thus, there are two prongs to the New Mexico statutory definition of mental retardation: (1) significantly subaverage general intellectual functioning and (2) deficits in adaptive behavior. This language closely tracks the definition of mental retardation found in the DSM but the DSM adds a third prong. See DSM at 41. Under the DSM, one's symptoms must have begun before age eighteen in order to be classified as mental retardation. Id. The State urges us to read in the age of onset requirement so that the definition in Section 31-9-1.6 would mirror the DSM definition. Under this formulation, Defendant, whose disorder did not begin until his mid-twenties, would not be classified as having mental retardation. {11} In interpreting a statute, our primary objective is to give effect to the Legislature's intent. State v. Davis, 2003-NMSC-022, ¶ 6, 134 N.M. 172, 74 P.3d 1064. In discerning legislative intent, we look first to the language used and the plain meaning of that language. Id. Under the plain meaning rule, when a statute contains clear and unambiguous language, we will heed that language and refrain from further statutory interpretation. State v. Rivera, 2004-NMSC-001, ¶ 10, 134 N.M. 768, 82 P.3d 939. We will not read into a statute any words that are not there, particularly when the statute is complete and makes sense as written. Burroughs v. Bd. of County Comm'rs of Bernalillo County, 88 N.M. 303, 306, 540 P.2d 233, 236 (1975). {12} Because the language used in Section 31-9-1.6(E) to define mental retardation is strikingly similar to that of the DSM, we can infer that the Legislature was aware of the DSM definition, and the critical third prong, and declined to adopt it. The Legislature's decision to exclude the age of onset factor is logical given that what is legally relevant are the symptoms probative of culpability at the time of the alleged crime and coherence at the time of trial, not the age at which those symptoms started to affect the individual. {13} To be sure, we have previously recognized the differing purposes of the legal and medical definitions of insanity: through the legal definition, the law seeks to assess accountability, whereas psychiatry's purpose is to diagnose and cure mental illnesses. State v. Neely, 112 N.M. 702, 707, 819 P.2d 249, 254 (1991) (internal quotation marks and citation omitted). Even the DSM itself warns of the significant risks of importing its categories and criteria to the legal setting: dangers arise because of the imperfect fit between the questions of ultimate concern to the law and the information contained in a clinical diagnosis. DSM at xxxii-xxxiii. Because the Legislature's omission of the age of onset requirement is clear and unambiguous and, further, because the age of onset of one's symptoms is not legally relevant, we affirm the Court of Appeals and hold that the New Mexico statutory definition of mental retardation does not contain such a requirement. See Rivera, 2004-NMSC-001, ¶ 10, 134 N.M. 768, 82 P.3d 939. Defendant has mental retardation under New Mexico law. We now turn to the more opaque issue: what the State may do when faced with a defendant who is dangerous, incompetent due to mental retardation, and without a substantial probability of gaining competence.