Trigger Dr has raised an interesting point. The RCW does not appear to allow the City to legally destroy these guns!
9.13.040 Disposal of forfeited firearms.
Any firearms seized by and forfeited to the City pursuant to State law shall be turned over to the chief law enforcement officer, who may to the extent allowed under RCW 9.41.098 dispose of said firearms as follows:
(a) The chief law enforcement officer may retain legal forfeited firearms for Police Department use, subject to the limitations of RCW 9.41.098(2)(b);
(b) The chief law enforcement officer may sell legal forfeited firearms at auction, or in any other manner allowed by law;
(c) Illegal forfeited firearms, defined as those firearms that are illegal to possess, must be destroyed. (Ord. 01-702 § 5; Ord. 08-864 § 1).