RCW 12.04.090Proof of service.Proof of service in either of the above cases shall be as follows: When made by a constable or sheriff his or her return signed by him or her and indorsed on the paper or process. When made by any person other than such officer, then by the affidavit of the person making the service.[ 2010 c 8 s 3007; Code 1881 s 1719; 1873 p 337 s 26; RRS s 1765.]
Washington Legal Code