Wash. Rev. Code § 35.13.380
(1) An eligible employee under RCW 35.13.370 may transfer into the civil service system for the police department by filing a written request with the civil service commission of the affected city, code city, or town and by giving written notice thereof to the legislative authority of the county. Upon receipt of such request by the civil service commission the transfer shall be made. The employee so transferring will:
(3) The thirty-six month period contained in subsection (2) of this section shall commence:
[ 1993 c 189 s 4.]