Washington Revised Code Title 10. Criminal Procedure § 10.34.010. Officer may arrest defendant in any county

If any person against whom a warrant may be issued for an alleged offense, committed in any county, shall either before or after the issuing of such warrant, escape from, or be out of the county, the sheriff or other officer to whom such warrant may be directed, may pursue and apprehend the party charged, in any county in this state, and for that purpose may command aid, and exercise the same authority as in his or her own county.