Wash. Rev. Code § 9A.12.010
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:
[ 2011 c 336 s 353; 1975 1st ex.s. c 260 s 9A.12.010.]