Diminished capacity provides a defense for defendants who suffer from mental disease or deficiencies in their thought process to such an extent that the defendant's capacity to form the appropriate mens rea, or specific mental element required by the criminal statute, is impaired. Under diminished capacity the defendant's mental impairment does not rise to the level of an insanity defense, but does prevent the defendant from, for example, having the mental element of malice as required for a charge of murder. The cases that have dealt with the defense of Cultural Norms have the unique distinction of dealing almost exclusively with male immigrant defendants who have murdered their mates.
In People v. Aphaylath, 68 N.Y.2d 945, 502 N.E. 2d 998 (1986) Defendant, a Laotian refugee living in this country for approximately two years, was indicted and tried for the intentional murder of his Laotian wife of one month. At trial, defendant attempted to establish the affirmative defense of extreme emotional disturbance to mitigate the homicide on the theory that the stresses resulting from his status of a refugee caused a significant mental trauma, affecting his mind for a substantial period of time, simmering in the unknowing subconscious and then inexplicably coming to the fore. Although the immediate cause for the defendant's loss of control was his jealousy over his wife's apparent preference for an ex-boyfriend, the defense argued that under Laotian culture the conduct of the victim wife in displaying affection for another man and receiving phone calls from an unattached man brought shame on defendant and his family sufficient to trigger defendant's loss of control.
The defense was able to present some evidence of the Laotian culture through the cross-examination of two prosecution witnesses and through the testimony of defendant himself, although he was hampered by his illiteracy in both his native tongue and English. The trial court refused to allow defendant to present two expert witnesses concerning the stress and disorientation encountered by Laotian refugees in attempting to assimilate into the American culture. The appeals court found Defendant's ability to adequately establish his defense was impermissibly curtailed by the trial court's exclusion of the proffered testimony of the two expert witnesses. Because defendant was deprived of an opportunity to put before the jury information relevant to his defense of cultural norms, a new trial was ordered.
