If an arrest is made in this state by an officer of another state in accordance with the provisions of RCW 10.89.010, he or she shall, without unnecessary delay, take the person arrested before a magistrate of the county in which the arrest was made, who shall conduct a hearing for the purpose of determining the lawfulness of the arrest. If the magistrate determines that the arrest was lawful, he or she shall commit the person arrested to await for a reasonable time the issuance of an extradition warrant by the governor of this state. If the magistrate determines that the arrest was unlawful, he or she shall discharge the person arrested.
RCW 10.89.020