Wash. Rev. Code § 10.16.110
It shall be the duty of the prosecuting attorney of the proper county to inquire into and make full examination of all the facts and circumstances connected with any case of preliminary examination, as provided by law, touching the commission of any offense wherein the offender shall be committed to jail, or become recognized or held to bail; and if the prosecuting attorney shall determine in any such case that an information ought not to be filed, he or she shall make, subscribe, and file with the clerk of the court a statement in writing containing his or her reasons, in fact and in law, for not filing an information in such case, and such statement shall be filed at and during the session of court at which the offender shall be held for his or her appearance: PROVIDED, That in such case such court may examine such statement, together with the evidence filed in the case, and if upon such examination the court shall not be satisfied with such statement, the prosecuting attorney shall be directed by the court to file the proper information and bring the case to trial.
RCW 10.16.110