RCW 72.23.170

Any person who procures the escape of any patient of any state hospital for the mentally ill, or institutions for psychopaths to which such patient has been lawfully committed, or who advises, connives at, aids, or assists in such escape or conceals any such escape, is guilty of a class C felony and shall be punished by imprisonment in a state correctional institution for a term of not more than five years or by a fine of not more than five hundred dollars or by both imprisonment and fine.