RCW 9A.12.010Insanity.To establish the defense of insanity, it must be shown that:(1) At the time of the commission of the offense, as a result of mental disease or defect, the mind of the actor was affected to such an extent that:(a) He or she was unable to perceive the nature and quality of the act with which he or she is charged; or(b) He or she was unable to tell right from wrong with reference to the particular act charged.(2) The defense of insanity must be established by a preponderance of the evidence.[ 2011 c 336 s 353; 1975 1st ex.s. c 260 s 9A.12.010.]
Washington Legal Code