The History Leading to the Current Definition of Mental Retardation

In Nixon v. State, 2 So. 3d 137, 141 (Fla. 2009), the Supreme Court of Florida summarized the history leading up to the current definition of mental retardation in Florida: In 2001, the Florida Legislature enacted section 921.137, Florida Statutes (2001), which barred the imposition of a death sentence on the mentally retarded and established a method for determining which capital defendants are mentally retarded. See 921.137, Fla. Stat. (2001). The following year, the United States Supreme Court issued its opinion in Atkins v. Virginia, 536 U.S. 304, 122 S. Ct. 2242, 153 L. Ed. 2d 335 (2002), holding that execution of mentally retarded offenders constitutes "excessive" punishment under the Eighth Amendment. In response to Atkins and section 921.137, the Court promulgated Florida Rule of Criminal Procedure 3.203, which specifies the procedure for raising mental retardation as a bar to a death sentence. Pursuant to both section 921.137 and rule 3.203, a defendant must prove mental retardation by demonstrating: (1) significantly subaverage general intellectual functioning; (2) concurrent deficits in adaptive behavior; (3) manifestation of the condition before age eighteen. See 921.137(1), Fla. Stat. (2007); Fla. R. Crim. P. 3.203(b). The Nixon Court also summarized the appropriate standard of review for mental retardation determinations: When reviewing mental retardation determinations, we must decide whether competent, substantial evidence supports the trial court's findings. See Cherry, 959 So. 2d at 712 (citing Johnston v. State, 960 So. 2d 757 (Fla. 2006)). The Court do not "reweigh the evidence or second-guess the circuit court's findings as to the credibility of witnesses." Brown v. State, 959 So. 2d 146, 149 (Fla. 2007) (citing Trotter v. State, 932 So. 2d 1045, 1049 (Fla. 2006)). However, we review the trial court's legal conclusions de novo. See Sochor v. State, 883 So. 2d 766, 771-72 (Fla. 2004). Id.