State v. MaloneAnnotate this Case
The Supreme Court affirmed Defendant's conviction for premeditated first degree murder, holding that a defendant who introduces expert evidence of a character trait for impulsivity to challenge premeditation cannot introduce evidence of brain damage to corroborate the existence of that trait.
On appeal, Defendant argued that the trial court abused its discretion by precluding expert testimony from a psychologist that Defendant likely had diffuse brain damage, meaning that he was more likely to have a character trait for impulsivity. The court of appeals agreed, holding that the trial court erred by precluding the testimony but that the error was harmless. The Supreme Court vacated the court of appeals' opinion and affirmed, holding (1) mental disease or defect evidence cannot be admitted to show that a defendant was less likely to have formed the mens rea element of a crime even if that evidence corroborates behavioral-tendency evidence; and (2) the trial court did not err in precluding the expert from testifying that Defendant suffered from brain damage even if the impairment made it more likely that Defendant had a character trait for impulsivity.