Wash. Rev. Code § 81.60.020
Any railroad corporation desiring the appointment of any of its officers, agents, or servants not exceeding twenty-five in number for any one division of any railroad operating in this state as railroad police officers shall file a request with the criminal justice training commission on an approved application form. The application shall be signed by the president or some managing officer of the railroad corporation and shall be accompanied by an affidavit stating that the officer is acquainted with the person whose appointment is sought, that the officer believes the person to be of good moral character, and that the person is of such character and experience that he or she can be safely entrusted with the powers of a police officer.
For the purposes of this section, "division" means the part of any railroad or railroads under the jurisdiction of any one division superintendent.
RCW 81.60.020