Where any person is charged in the superior court in this state with a sex offense and it appears that such person is a sexual psychopath, the prosecuting attorney may file a petition in the criminal proceeding, alleging that the defendant is a sexual psychopath and stating sufficient facts to support such allegation. Such petition must be filed and served on the defendant or his or her attorney at least ten days prior to hearing on the criminal charge.
RCW 71.06.020