Wash. Rev. Code § 9A.12.010
Insanity
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) H…