PDFRCW 18.165.060
Armed private investigator license authority—Registration of firearms.
(1) An armed private investigator license grants authority to the holder, while in the performance of his or her duties, to carry a firearm with which the holder has met the proficiency requirements established by the commission.
(2) All firearms carried by armed private investigators in the performance of their duties must be owned by the employer and, if required by law, must be registered with the proper government agency.